Rhine-Maas Delta

	Rhine-Maas Delta
	The confluence of the Rhine and Maas from the west. Front: Rotterdam ports and Haringvliet ; Middle right: mouth of the Meuse
	Data
location	Netherlands , Germany , Belgium
River system	Rhine and Scheldt
Important waters of the delta area	Rhine , Waal , Merwede , Nieuwe Merwede , Noord , Nieuwe Maas , Nederrijn , Lek , (Gelderse) IJssel , Maas , Schelde , Oude Rijn , Vecht , Hollandse IJssel , Linge (for more see the section on water list ) Coordinates: 51 ° 44 ′ N , 4 ° 43 ' O 51 ° 44' N , 4 ° 43 ' O;
Catchment area	240,140 km² (rounded); Rhine: 218,300 km², Scheldt: 21,863 km²

The Rhine-Maas delta , more rarely called the Rhine-Maas-Scheldt delta , is the joint area of the mouth of the rivers Rhine , Maas and Scheldt in the northwest of mainland Europe into the southern North Sea . The Meuse flows into the Rhine, but was an independent river between 1904 and 1970. The transitions to the estuaries of the Scheldt estuary are smooth. It is a complex post-glacial deposit that has existed for about 6000–7000 years BC. Formed by extensive river deposits. Whether the designation as a river delta does justice to the character of the estuary is controversial due to the strong influence of the tides (see section estuary type ) , which means that there are no clear criteria for spatial delimitation. The horizontal and vertical interlocking of the different sediment bodies is hardly clear. The delta includes river branches and shifts, former and still existing estuaries, bays , coastal dunes , beach ridges , polder landscapes , depressions and peat-excavated lakes.

General

Dating

Radiocarbon calibration curve

The abbreviations commonly used in the literature are used for the times. In this article, different units are used for Holocene and Pre-Holocene information:

Times for the Holocene:

BC = Before Christ = v. Chr.
AD = Anno Domini = AD

Information for older periods:

mya = million years ago = million years ago today, e.g. B. 2.6 mya = 2,600,000 years ago

BP = Before Present = before today, e.g. B. 780,000 BP (partly based on 1950)

All dates of the Holocene age are converted into BC / AD information below. The uncalibrated dates obtained by the C-14 method and found in the literature have been converted.

designation

The simpler term Rhine delta also applies to the Rhine delta on Lake Constance . The extended expression Rhine-Maas-Schelde-Delta includes the seamlessly adjacent estuary of the Scheldt with its two large estuaries , especially with regard to the overarching hydraulic engineering measures of the Delta Works .

Muzzle type

The Wax Lake Delta in the mouth of the Mississippi fulfills classic ideas of a river delta

Estuarine delta of the Amazon : branches (delta formation) and estuary funnels (estuaries)

Older geological definitions understood a river delta to be an area of river deposits that is formed by rivers branching off and extends convexly beyond a coastline. According to more recent definitions, the southern part of the Rhine-Maas-Scheldt delta is an estuard delta. Estuard deltas are characterized by sedimentation and erosion . In the Rhine-Maas Delta there are areas due to the rise in sea level in which sedimentation initially predominated, so that the rise of the river beds caused ramifications, while later storm surges and tidal currents widened estuaries to form estuaries. Because erosion has predominated in the last few centuries, some authors refuse to refer to the confluence of the Rhine and Maas as a delta .

overview

Location and characteristics

Blue: areas in the Netherlands below sea level, bodies of water

The delta is part of a flat coast that stretches from Artois to Denmark . It consists of marshland areas that range from 30 km ( Bergen op Zoom ) to 125 km (Rhine bifurcation near Millingen ) inland, with wadden and dune areas in front of them. The mouths of larger rivers have been widened to estuaries by the tides flowing in and out . Of these, those from (Gelderser) IJssel , Maas and Schelde are closely linked to the mouth of the Rhine. Large areas are up to 6.7 meters below sea level (north of Rotterdam ) due to polders or peat extraction .

Most of the mouths of the Rhine, Meuse and Scheldt are located in the Netherlands . Small parts are located in Germany (beginning of the Holocene sedimentation area on the Lower Rhine near Emmerich ) and in Belgium (inner parts of the Scheldt estuary). The pre-Holocene deltas or mouths of the Rhine were located between the discharge of the Rhine from the Rhenish massif (near Bonn ) and the English Channel (sea level depression in cold periods ).

Large parts of this delta were created in the classic way through sedimentation and the resulting avulsions (shifts of the main streams from sanded up river arms to newly formed ones). The estuaries In the southern area, i.e. the province of Zeeland , a system of interconnected estuaries has arisen due to the action of the sea, mainly coastal subsidence , storm surges and tidal currents . The fact that these mainly branch out towards the sea shows, however, that the sea incursions followed estuaries by rivers.

Relief map of the Netherlands, also drawn the provincial borders

Core areas of the Holocene Delta are formed by fluvial deposits that extend roughly between Rotterdam and Amsterdam in the west and Nijmegen and Emmerich in the east, and the valley of the (Gelders) Issel in the northeast has been added since around 200 AD. The delta sediments are between 1 and 25 meters thick and essentially consist of sediment bodies from the Rhenish system. These fluvial sediments are interspersed horizontally and vertically with marine , tidal and other sediments. Marine and similar deposits are found particularly in the west and north, from Zealand to the IJsselmeer . Neighboring the Holocene delta areas are Pleistocene, partially sand- and loess-covered moraine and terraced areas . (See the chapter Elements of the Holocene Delta .)

The hydrogeography of the current river delta is characterized by river arms of different sizes, tidal waters, estuaries, lakes, small drainage and large ship canals. Since around 1100 AD, many rivers have been separated ("dammed") from the active river system by dams and have served since then, like the dense canal system, for draining the polders. There are only a few active drainage routes left. Their names change frequently due to the many natural and artificial river shifts (avulsions and canal constructions). The two river divisions in the uppermost part of the Rhenish system near Millingen and Arnhem as well as various regulatory measures lead to the following three main strands:

Northeast region of the delta. On the right the (Gelderse) IJssel , on the left (green) the terminal moraine range of the Veluwe , above the IJsselmeer

Rhein - Waal - Boven (Obere) Merwede - Nieuwe (Neue) Merwede : The Waal was created around 200 BC and developed into by far the strongest, most water-rich delta arm in the first millennium AD. After the Meuse confluence, Hollands Diep and Haringvliet are widened , created from former sea bays. At the Haringvlietdamm the river arm reaches the North Sea. The Neue Merwede as the left arm of the Upper Merwede replaced the so-called Maas estuary near Rotterdam as the most important Rhine outlet in the 19th century and takes in the main water volume, especially when there is a large water flow. The Beneden (Lower) Merwede, which branches off to the right, is more important as a shipping route than the New Merwede. For historical reasons, the name Waal is sometimes used collectively for the Waal – Merwede – Noord section (see below).
Nederrijn - Lek : This middle delta arm was created in the first millennium BC at the latest. Nederrijn and Lek later lost their position as the main delta arm on the Waal (see above). At the turn of the century, the Lek gradually replaced the lower course, which ran further north towards Amsterdam and is now only marked by the small watercourses Kromme Rijn and Oude Rijn (see below). Often the entire delta arm is called Nederrijn , the actual Nederrijn sometimes just Rijn . Further to the west, it joins the Noord, which comes from the Waal, and passes the city center of Rotterdam as the New Maas (see below).
IJssel : The IJssel branches off in a bifurcation near Arnhem from the Nederrijn to the north, flows through the IJsselmeer and flows into the North Sea via outlets at the dike . The connection between Nederrijn and Issel (see below), which flows in from the right today , was not established until around 200 AD. The IJssel follows the course of an earlier arm of the Rhine that can be proven up to the last pleniglacial (approx. 73,000–14,500 years BP).

The right arm of the Merwede, the Beneden Merwede, is divided into two roughly equal arms near Dordrecht:

The Noord as the right arm unites with the Lek and flows into the North Sea as the Nieuwe (Neue) Maas and Nieuwe Waterweg . The New Maas roughly marks the northern edge of the former so-called Maas estuary, which was the main outlet for the Meuse and Rhine (Lek, Waal) since the first millennium BC.
The Oude (Alte) Maas as the left arm flows into the Nieuwe Maas in the port of Rotterdam. The Dordtsche Kil branches off to the south-west of Dordrecht . This short connection to Hollands Diep was artificially created a few centuries ago.

The main arm of the delta was the Kromme-Rijn - Oude-Rijn stretch until around 850 BC , which is sometimes simply called Oude Rijn. After its water flow had decreased in favor of the Lek, it was separated by a dam in 1122 AD and thus became an independent body of water that flowed into the North Sea at Katwijk .

Over the past millennia, the Meuse has flowed into side arms or, since the Waal has been the most important arm of the Rhine (1st millennium AD), at various points into the main arm of the Rhine. In 1904, however, the mouth of the Meuse was relocated downstream for flood protection reasons; following its course in Roman antiquity , it was connected to the Amer (lower course of the Donge ), whose estuary had already become an estuary of the Rhine with the construction of the Nieuwe Merwede in the years 1861 to 1874.

The Scheldt initially flowed separately from the Rhine and Meuse. During the great sea invasions in the first millennium AD, however , new tidal beeches and numerous cross connections formed between the original Scheldt estuary ( Oosterschelde ) and the Maas estuary near Rotterdam. In addition, the Westerschelde developed south of the Oosterschelde as the second Scheldt estuary . So the mouths of the three (or four with the Donge that feeds the Amer ) rivers.

Water distribution and amounts of water

Average proportions of the various branches of the estuary in the runoff of the Rhine and Maas;
Salinity: IJsselmeer, Markermeer u. Grevelingen low, Oosterschelde high

The mean flow rate of the Rhine (length approx. 1235 km) is around 2300 m³ / s (min. 620, max. 13,000) significantly higher than that of the Meuse (length 925 km) with approx. 357 m³ / s (min. 30, max . 3000). The mean annual runoff of the Scheldt (430 km) is 127 m³ / s (max. 2300).

The water of the Rhine (100%, 2200 m³ / s) is distributed over the main delta arms in a controlled manner as follows: At the Rhine bifurcation near Millingen the Waal receives 67% and the Nederrijn 33% of the Rhine water. After the junction of the Gelders IJssel, it carries 11%, the Nederrijn-Lek-Strom still 22% of the Rhine water. 65% of the stream Waal-Obere-Merwede flows into the Neue Merwede (that is 44% of the total Rhine water) and 35% into the Untere Merwede (23% of the total Rhine water). The normal distribution of Rhine water over the Waal, Nederrijn and IJssel in the ratio 67:22:11 is changed to 75: 16: 9 at low tide and to 66:11:23 at high tide. The various barrages and weirs are controlled in such a way that around 1500 m³ / s reach the North Sea via the most important shipping route, the Nieuwe Waterweg.

Mouth points

At present, Rhine water still flows into the sea at five points (partly via former sea bays). From south to north these are

The gates of the Haringvliet dam. Here, depending on the Lobith gauge on the Lower Rhine, it is decided in which proportions the water from the Rhine with Maas reaches the North Sea here or via the Nieuwe Waterweg in Rotterdam.
The Nieuwe Waterweg with the parallel Hartel Canal . Your water flow is kept as constant as possible. In years of low water flow from the Rhine, around half of the water from the Rhine and Maas reaches the sea.
Amsterdam-Rijn-Kanaal - the IJ - Noordzeekanaal
The two tidal barriers in the closing dike of the IJsselmeer from Den Oever ( Stevinsluizen ) and Kornwerderzand ( Lorentzsluizen ) . The IJssel reaches the sea via these mouths .

Until the 17th century, the Scheldt had two parallel estuaries, the Westerschelde and the Oosterschelde . Today all water of the Scheldt reaches the sea through the Westerschelde, which was not changed when the delta was redesigned. The Oosterschelde silted up in the course of the 17th and early 18th centuries near its point of departure and was finally dammed, but received water from the Meuse for centuries. Today it is a sea bay protected from storm surges by an elaborate barrage with only a small headwater (inflow from the inland).

List of waters

The river system of the Rhine and the Rhine-Meuse delta

The Rhine-Maas Delta comprises the following more important bodies of water:

Current or earlier estuarine waters and arms with sections:

the Rhine (Rijn) with the sections of the Bijlandskanaal and the Boven Waal (Obere Waal)

the Waal with the sections of the Beneden Waal (Untere Waal) and the Upper Merwede (Boven Merwede)

the Nieuwe Merwede (New Merwede)

the Dorche Kil

the spui

the Bernisse

the Lower Merwede (Beneden Merwede)

the Noord (formerly t noort diep , "Nordtief"), which after merging with the Lek forms the Nieuwe Maas (New Maas) flowing through Rotterdam

the Oude Maas (Alte Maas), which takes up the Spui and, after merging with the Nieuwe Maas, forms the Scheur and then the Nieuwe Waterweg (New Waterway, Rotterdam Waterway, the most important mouth of the Rhine)

the Pannerdens Canal , also De Nieuwe Rijn (The New Rhine)

the Nederrijn (Lower Rhine), the Lek

the IJssel , also known as Gelderse (Geldersche) IJssel to distinguish it from the Dutch IJssel (see below), with the Keteldiep estuary

the Maas , last called the Bergsche Maas and the Amer , flows into the lake-like arm of the Rhine in Holland's Diep around 40 km before reaching the North Sea

the Vechte with the mouth section Zwarte Water (black water), flows into the IJssel-See and thus reaches the North Sea as a tributary of the IJssel

the Scheldt

The Bergsche Maas with the Keizersveer bridge, branching off to the right the Oude Maasje

Estuaries

Hollands Diep , active, upper inlet of the Haringvliet

Haringvliet , outflow of the Hollands Diep, active, at the mouth of the Haringvlietdam tidal barrier
Volkerak , suspended from the upper water, formerly the southern branch of the Hollandsdiep
Grevelingen , dammed, formerly the northern branch of the mouth of the Volkerak
Oosterschelde , tides preserved, storm surge barrier , suspended from the upper water together with Volkerak, formerly tributaries from the Rhine, Maas and Scheldt
Westerschelde , active

Other rivers or stretches of rivers (partly inactive due to damming):

Issel (Oude IJssel), today tributary of the IJssel, once its upper course
the Berkel , tributary of the IJssel
the Schipbeek , tributary of the IJssel
the Kromme Rijn (Krummer Rhein) passing into the Oude Rijn (Old Rhine) and the Leidse Rijn (Leidenscher Rhein)

the Utrechtsche Vecht which flows into the IJsselmeer

Hollandse IJssel , which flows into the Nieuwe Waterweg (only dammed in the upper reaches, transports Rhine water despite damming)

the Linge , whose water is branched off from the Pannerdens Canal and flows to the Waal

the Afgedamde Maas (Dammed Maas), the Oude Maasje ( diminutive of Alte Maas)

the Vliet

the Brielse Maas (Brielsche Maas, formerly also the Brielse Diep - "Brielsche Tief " - called)

the Gedempte Devel

the Oude Waal (Alte Waal, on the division of the Rhine)

the Oude Waal (Alte Waal, Altarm west of Dordrecht)

the Old Rhine / Oude Rijn (on the division of the Rhine), the Jezuitenwaai, De Keel

Inactive (dammed) creeks u. Ä .:

Alblas, Aa, Aar, Amstel, Does, Drecht, Gouwe, Kromme Angstel, (Kromme) Mijdrecht, Rotte, Schie, Vlaarding, Ziel and others

Wetlands rich in water:

Biesbosch (with Bakkerskil, Steurgat and others)

Lakes:

the IJsselmeer (the "Isselsee", former names: Zuiderzee, Flevosee, Almere, Eemmeer), IJ , Haarlemmermeer , Leidsemeer , Braassemermeer , Westeinderplassen , Grevelingenmeer (Grevelingen) with Volkerak, Haringvliet (Westerleek; second most important Rhine mouth point ( ), Holland's most important confluence point of the Rhine "Dutch Depth"), Brielse Meer ("Brielscher See"), Oostvoornse Meer ("Ostvoornscher See")
Grevelingen , dammed estuary, s. O.

The North Sea Canal at IJmuiden

Channels:

Vaartse Rijn , Kanaal door Voorne , Kanaal van Steenenhoek , Merwedekanaal , Maas-Waalkanaal , Canal von Sint Andries , Amsterdam-Rijnkanaal , Schelde-Rijnkanaal , Noordzeekanaal , Heudens Kanaal , Rijn-Schiekanaal (Vliet, Delftse Vliet,)

Former waters (selection):

Maas estuary (Maasmond, Ostium Helinium), Leiden estuary (mouth of the Oude Rijn, see above)
Ur-IJ (connection between Lake Flevo and the North Sea in the area of today's North Sea Canal)
Flie (connection between Lake Flevo and the North Sea in the north)
former rivers: Benschop, Werkhoven, Linschoten, Houten, Werken, Dort, Dubbel u. v. a.

Hydrogeographic description

The following hydrogeographic descriptions refer to the current waters of the delta area.

Along the main stream

The eastern border of the Holocene sedimentation area and thus the area known today as the delta lies near the current and earlier river divisions below Emmerich. Up until the eighteenth century, the main route of the Rhine divided for centuries at Schenkenschanz and Lobith .

First fork in the Rhine (near Millingen): to the left the Waal, to the right the Nederrijn

At the current division of the Rhine, in the immediate vicinity of the Dutch-German state border at Millingen , the Rhine initially forks into two main arms flowing westwards, the northern Nederrijn ("Niederrhein", but here called Nederrijn to avoid confusion with the German section of the Rhine) and the southern Waal. Shortly afterwards the third main arm branches off from the Nederrijn to the north, the (Geldersche) IJssel.

The Meuse used to flow into the Waal at Gorinchem , and between 1904 and 1970 it reached the Hollands Diep bay, separated from the Rhine system via Bergse Maas and Amer. Today it is re-integrated into the system of water in the mouth of the Rhine through the Haringvliet dam. Until 1421, the Maas flowed a little south of the current Merwede-Oude Maas line towards the North Sea and formed a common, archipelago-like estuary with the Waal and Lek . The westernmost estuary, at the level of the dune chains interrupted here, was already called in ancient times at the latest and is still called the Meuse Estuary today (left Maasmond, in geographical literature mostly Maas estuary ).

The Waal near Loevestein

The Waal is the main river of the delta and carries about 67% of the Rhine water. Without the Rhine water regulation, the Waal would possibly carry all of the Rhine water. The first section to around Gendt (municipality of Lingewaard ) and the section of the Rhine between the current division of the Rhine and the earlier upstream section at Schenkenschanz, once the uppermost section of the Waal, is man-made and is called the Bijland Canal.

At the current approach to the river near Heerewaarden , the Maas used to flow into the Waal, later the Maas water looked for a new route to the southwest. The two currents used to mix here, probably not only during floods. Opposite Gorinchem the Meuse flowed from the left until 1904, the remaining arm is called Afgedamde Maas . From this former Meuse confluence, the Rhenish main delta arm is called Merwede. The name Waal used to extend further downstream - an indication of this is given by the name Waal for the small river course between North and Old Maas northwest of Dordrecht in the area of an earlier course.

The Biesbosch. In the foreground the Maas (Amer), in the middle distance the New Merwede

Below Gorinchem, the main delta arm is called Boven Merwede (Obere Merwede). The Neue Merwede branches off at Werkendam and takes over 65% of the Upper Merwede. The Neue Merwede has been artificially expanded to its current capacity and directs around 44% of the entire Rhine water to the sea and thus more than any other of the five estuaries of the Rhenish system. It flows through the western part of the Biesbosch and through the former Hollands Diep bay to the North Sea.

Like the IJsseldelta, the Biesbosch ("rush forest") is a relatively active young delta area and lies between Merwede in the north and Amer in the south. The Biesbosch is mainly fed by Rhine water (Merwede), but to a very small extent also by Maaswasser (Amer, Bergse Maas).

Area Untere Merwede, Noord, Neue Maas

The Beneden Merwede (Untere Merwede) takes over about 35% of the water volume of the Upper Merwede. The Untere Merwede divides at Dordrecht into the Noord and the Alte Maas. The North merges into the New Maas. In the mouth of the Rhenish Delta, the name of the Meuse is mainly used, which has its reasons in the historical course of the Meuse (see palaeographic development ).

From the north, a river called Waal branches off to the left about halfway, marking an earlier course of a delta main arm. At Krimpen aan de Lek the Lek flows from the right. From here on the river is called Neue Maas. Shortly below the confluence of the Lek , the Dutch IJssel also flows from the right, at Krimpen aan den IJssel. The Old Maas flows from the south in the area of the old port of Rotterdam. Between Rotterdam and the North Sea, the New Maas forms the backbone and northern border of one of the largest port facilities in the world. In this context, the last kilometers of the New Maas, from around Maassluis, were expanded to the Nieuwe Waterweg ("New Waterway"). In the Maassluis area, the course of the river is also called Scheur, after an earlier branch. The mouth of the New Maas is called Maasmond ("Maas mouth", seldom Mond van de Maas) and represents the entrance to the ports of Rotterdam. The most recent facilities of the port of Rotterdam were built in the area of the Maas mouth (first Europoort , later Maasvlakte ).

The Alte Maas begins at Dordrecht as the left branch of the Merwede. Just below Dordrecht, the Dordtse Kil branches off to the left, which joins the Hollands Diep after a few kilometers. At Heerjansdam a small river called Waal flows from the right, marking an earlier course of the Waal or a delta main arm. At Oud-Beijerland , the Spui branches off to the left, which flows through the former island of Putten and flows into the Haringvliet. At Spijkenisse , the Brielsche Maas branches off to the west. The Bernisse lies between the Spui and the Brielschen Maas.

The Brielse Maas branches off from the Old Maas at Spijkenisse. Its confluence with the North Sea was blocked off and built so that it now has the character of a still water. The inland waters of Brielsemeer and Oostvoornse Meer can now be found in the former estuary area. The Brielse Maas flowed parallel to the New Maas and essentially forms the southern border of the Rotterdam port facilities.

Nederrijn area

The Nederrijn near Arnhem

The Nederrijn is also called Pannerdense Kanaal between its beginning near Millingen and the confluence of the oxbow lake Oude Rijn ("Old Rhine"), an artificially created river section of the 18th century named after the nearby town of Pannerden . The Oude Rijn, which flows into Loo, marks an earlier course of the (Neder-) Rijn when the Rhine was divided further upstream. At Pannderden, the Linge branches off to the left from the Pannerden Canal. The IJssel branches off at Arnhem. The landscape north of the Nederrijn and west of the IJssel is called the Veluwe , the landscape south of the Nederrijn Betuwe . The Gelderse Vallei ("Geldersche Tal") stretches north from Wageningen to the former Zuiderzee . At Wijk bij Duurstede, the Krumme Rhine, which is now dammed, branched off, the main stream continues in the Lek.

The Lek at Lekkerkerk

Mouth of the Oude Rijn near Katwijk.

Even if the river dike is already called Lekdijk ("Lekdeich") from Amerongen (municipality of Utrechtse Heuvelrug ) - the middle main delta arm is only called Lek after the branching off of the Crooked Rhine. The Dutch IJssel branches off at Nieuwegein . At Krimpen aan de Lek, the Lek flows into the New Meuse.

The IJssel near Deventer

The IJssel is also called Geldersche IJssel to distinguish it from the Dutch IJssel (tributary of the Lek). Several longer tributaries flow into locks from the right: the Issel (Oude IJssel, Alte Issel), the Berkel and the Schipbeek. Up to the confluence of the Alte Issel, the IJssel is also called Nieuwe IJssel (Neue Issel). The IJssel flows into the sweet IJsselmeer, where it forms its own active delta, the main arm of which is called Keteldiep. The mouth of the IJssel overlaps with that of the Vechte, whose main delta arm is called the Zwarte Water. Until the Zuiderzee was dammed , the IJssel was under the influence of tides up to Katerveer (near Zwolle).

The IJsselmeer represents the southern part of the former Zuiderzee bay ("Südersee", "Südliches Meer"). In Roman times, the bay, which was also an inland lake for a certain time, was called Lacus Flevo, and in the Middle Ages it was also called Almere or Eemmeer. In the southwest, the IJ and Oer-IJ made a connection via Amsterdam to the North Sea. The bay of the Zuiderzee became the sweet IJsselmeer with the construction of the dike in 1932 . Subsequently, about half of the IJsselmeer was drained as part of the Zuiderzeewerke . The North Sea Canal is located in the area of the IJ and Oer-IJ, the former western connection between the Zuiderzee and the North Sea.

In the moor areas between Amsterdam and Oude Rijn, peat extraction meant that the existing moor lakes became larger and larger. The most important were the Haarlemmermeer and Leidsemeer. Most of the parts have now been drained; the Amsterdam Schiphol Airport is one area of the former Haarlemmermeer.

Crooked Rhine

The Oude Rijn (in the following not translated to differentiate it from various branches of the Old Rhine) is usually called Kromme Rijn in its upper reaches up to just before Utrecht , and also Leidse Rijn in Leiden . Contrary to the expectations that its name "Rhine" generates, the Oude or Krumme Rhein branching off the Nederrijn at Wijk bij Duurstede is only a small river. It even has the character of a still water, as it has been dammed since 1122 and is only supplied with water from the Nederrijn when the water level is very low. Otherwise it serves as a drainer for the surrounding polders. The Vecht (also called Utrecht Vecht) branches off to the north near Utrecht and flows into the IJsselmeer. The Oude Rijn flows into the North Sea near Katwijk. Today a canal follows this path. The original connection between Kromme and Oude Rijn has been completely cut - the water of the Krumme Rhine flows entirely into the Vecht. The landscape on the lower reaches of the Oude Rijn is called Rijnland ("Rhineland"). A little north of the Oude Rijn begins the Amstel , a developed tidal creek that flows into the IJ in Amsterdam .

The Dutch IJssel near IJsselstein

The Linge and the Dutch IJssel are two longer side arms that have been dammed since the Middle Ages. The Linge branched off to the left opposite Pannderden from the Nederrijn (Pannerdenscher Canal). The Linge used to branch off to the right here from the Waal. The Linge accompanies the Waal for many kilometers, flowing parallel to the north. Below Gorinchem the Linge flows into the Merwede. The Dutch IJssel branched off northwards from the Lek at Nieuwegein and flowed into the New Maas at Krimpen on the IJssel. At Gouda , the former Gouwe tidal creek branches off to the north from the IJssel and flows into the Oude Rijn at Alphen aan den Rijn . The Hollandse IJssel between Lek and Gouda no longer receives water from the Rhenish system, but only serves as a drainage device.

Meuse area

At Heerewaarden there is a river convergence between the Meuse and the Waal, which was not only the place of the (temporary or partial) confluence of the two rivers during floods. The Meuse used to flow into the Waal here, later at Woudrichem. From Heusden the Maas has been flowing since 1904 in the artificially developed bed of the Bergschen Maas and in the area of the Biesbosch as Amer, only to merge shortly afterwards in Hollands Diep with the Neue Merwede. Until 1904, most of the water from the Meuse flowed north at Heusden to flow into the Waal at Gorinchem. The old arm of Afgedamde Maas is evidence of this. The Heusdens Kanaal was built between the Bergse Maas and the Afgedamde Maas.

Area of the estuaries and the Scheldt

Zeeland 1580

The mouth of the Scheldt around Antwerp

Between the Belgian-Dutch state border in the south and the so-called Maas estuary in the north, the dune wall along the coast was breached in many places or never closed, especially during the late antique and medieval transgression phases. This is also due to the streams and rivers that flow here (Rhine, Maas, Scheldt), which have made it easier for the sea to penetrate behind the dune wall. From north to south, four major cuts can be seen today:

Haringvliet with Hollands Diep
Grevelingen (sea) with Volkerak
Oosterschelde
Westerschelde

The Scheldt flows into the Westerschelde. Between the incisions there are islands or former island areas. So there were water connections between the indentations. Some of these were removed as part of land reclamation, but shipping is still possible through the Rhine-Scheldt Canal between Antwerp in the south and the Volkerak in the north. The whole area underwent repeated massive changes through storm surges and human interference, most recently through the Delta Works . With the exception of the Wester- and Oosterschelde, all sea bays were separated from the sea by means of large barriers. This led to the extensive sweetening of the bays. The islands between the bays grew together partly through land reclamation with one another or with the mainland. The former extreme seclusion, especially of the Zeeland islands, was lifted by the use of the dams for road construction. The sea bay called Maasmond north of the Haringvliet, the Maas estuary, also belonged to these southwestern estuaries for a long time. The Maas estuary has been drained for the most part over the course of time, and the Rotterdam port facilities are now located in this area.

Creeks

The perimarinen, tidal dyke break channels and the tidal rivers must be separated from the river waters of the delta . They never had a natural connection to the Rhine and Maas, the existing connections were only established by humans by building canals. These canals and creeks were gradually used to drain the peat areas at low tide, giving them a river-like character. At high tide, estuarine sediments were deposited. Only a few of the creeks and canals that no longer exist have been dated. Some of the most important of these special waters are: Alblas, Lange Linschoten, Aa, Aar, Amstel, Does, Drecht, Gantel, Gießen, Gouwe, Kromme Angstel, Kromme Gießen, Lake, Lier, Lopikerwatering, Meije, Mijdrecht, Oude Waver, Rotte, Schie, Vlaarding, aim. Many of these creeks and canals were dammed in the late Middle Ages, as well-known place names testify (e.g. Amsterdam, Rotterdam, Schiedam). Modern equivalents are the so-called "Killen" of the Biesbosch.

Ship canals

Utrecht and the surrounding area: while the Amsterdam-Rhine Canal can be clearly seen, Krummer Rhein , Oude Rijn and Vecht are difficult to make out

The Amsterdam-Rhine Canal connects Amsterdam to the Waal via Utrecht and the Lek. The Merwede Canal runs from the Merwede over the Lek to Utrecht. The Waal-Maas Canal connects the two eponymous rivers near Nijmegen. The Scheldt-Rhine Canal begins at the Antwerp port facilities and extends north to the Volkerak, from where there is a connection to Hollands Diep. The North Sea Canal gives Amsterdam direct access to the North Sea. The Rhine-Schie Canal (sometimes called Vliet for short), which was built by the Romans, now connects the Neue Maas and Oude Rijn and stretches from Schiedam via Voorburg near The Hague to the Oude Rijn near Leiden (its three main sections are from south to north Delftse Schie , Called Delftse Vliet and Vliet).

Course of the tides in the delta

On the Waal, the tides make themselves felt as far as Werkendam (Rhine kilometer 960). The tidal wave initially flows into the Rotterdam ports. Part of the water flows over the Hartel Canal to the Oude Maas, the rest to the New Maas. The water reaches Hollands Diep via the Alte Maas and Dortse Kil. After around 45 minutes, the flood reaches the junction of the Old Maas (Rhine kilometer 1013) and 15 minutes later Rotterdam (Rhine kilometer 1000). Another 30 minutes later you have reached Krimpen an der Lek. After a total of two hours, the maximum water level is in Dordrecht (Rhine kilometer 975) and after three hours it is finally in Werkendam. In Moerdijk on Hollands Diep, the highest water level is only reached after 5 hours. The lowest water levels are all a little earlier. All values given are only approximate values, as the tide height and the water levels in the rivers change daily.

Paleogeographic evolution

Research history and methods

The center of geoscientific and palaeogeographic exploration of the Rhine-Meuse Delta is the informal Fluvial research group (also Fluvial group or Grupo Fluvial) in the Department of Physical Geography of the Faculty of Geosciences at the University of Utrecht . From this geological and geomorphological mapping work (scale 1: 10,000) was carried out in the second half of the 20th century, based on around 200,000 drill core descriptions (30–350 drillings per km²), 1,200 C14 data and data on 36,000 archaeological artifacts . The results of the work, which lasted around 40 years up to 2001, were published in 2001 for the first time in a combined and summarized form (Berendsen / Stouthamer 2001). The decade-long coordinator Henk JA Berendsen died in 2007, his successor is H. Middelkoop.

To reconstruct the paleogeographic development, Berendsen and Stouthamer described, named and dated 206 erosion remains of river beds in their standard work published in 2001. To date and connect these 206 riverbed fragments, they used the following methods: geological and geomorphological mapping, measurement of calcium carbonate content , analysis of soil formation , measurement of the relative depth of deposits outside the river beds (flood deposits), determination of the surface gradients of the river bed deposits (sand) and natural ones Dikes, pollen analysis , analysis of archaeological finds and historical documents and maps, dendrochronology and C-14 dating . A river bed (“channel belt”) is defined as an element that consists of river sediment bodies and flood plains bounded by dykes. The dykes themselves and river sediments deposited outside the dykes are not included. The river courses were reconstructed by connecting (dated) fragments of the riverbed that existed at the same time. The investigated river bed fragments and the river courses derived from them were in turn grouped into seven river systems (see chapter River systems ).

Development up to the beginning of the Pleistocene

Size and distance relationship between the moon and earth

After the formation of the moon (tides!) And the origin of the water cycle in the Hadean (about 4,570 to 3,800 mya ) formed probably in the Archean (ca. 3800-2500 mya) the continents , tide-influenced oceans and rivers. Among other things, the different climates , the drifting of the continents and other tectonic processes caused different sea levels. Mountains were formed and eroded.

The mountain complex of the Rhenish Massif was formed during the Variscan orogeny in the Devonian about 370 mya. The continent of Laurasia divided about 150 mya, and the North Atlantic emerged as a result. The current ground plans of the continents slowly formed. Another collision with the African plate caused the Alps to fold (since 100 mya).

The alluvial plains between Artois and the Baltic States

In the Miocene (about 23 to 5.3 mya ago), the North Sea basin was formed by further tectonic expansion movements. The oldest Rhine sediments also date from this epoch, when the Rhine was still a small river. It swelled on the northern edge of the Rhenish Slate Mountains, drained the ditch of the Lower Rhine Bay and flowed into the North Sea in North Rhine-Westphalia, working its way from the beginning of the alluvial plain near Bonn in a north-west direction to Cologne and Düsseldorf. From a geological point of view, the beginning of the first Rhine delta is near Bonn , where the Rhine leaves the Rhenish massif and enters the North Sea basin. The similarly small Meuse flows a little further west, but swells into the Ardennes ; the direction of flow was therefore northeast. The North Sea coast moved roughly along the Belgian-Dutch border to the then mouth of the Rhine in North Rhine-Westphalia and from there to the north to today's Dollart . The area of the Rhenish Slate Mountains and the Ardennes rose, the catchment areas of the Rhine and Maas increased; both processes shaped the entire neogene period and continue to this day.

In the Pliocene (about 5.3 mya before - in northwestern Europe - 2.6 mya) the coastline was essentially the same as in the Miocene. The Rhine in particular expanded its catchment area very significantly and encompassed large parts of the Moselle, Main and Neckar areas, its upper course perhaps following that of the Alsatian Ill . In the late Pliocene, the coastline shifted somewhat to the northwest. Rhine deposits can be found to the west and south of the current course of the Rhine in a wide strip between the Eifel along the Rur via Limburg and far to North Brabant .

Development in the Pleistocene

In contrast to the classification of the IUGS, the boundary between Pliocene and Pleistocene in northwestern Europe is set at 2.6 mya, the beginning of the Pleistocene and Quaternary thus coincide. The Pleistocene therefore includes all cold ages of the current Ice Age . It ends with the end of the last glacial period ( Vistula glaciation ) about 11,650 years ago (9,650 years BC).

Scree on the Baltic coast near Rostock

The Pleistocene is characterized by the frequent alternation between cold periods (glacials) and warm periods (interglacials). These phases are in turn divided into cooler and warmer times ( stadials and interstadials ), which is why instead of cold and warm times, the term "complexes" is often used (e.g. "Cromer complex" instead of "Cromer warm period") . Climate and climate change had a strong influence on the geomorphological development: in cold periods, areas further away from the poles were also icy, the sea level sank rapidly by many dozen of meters, the coasts shifted far seaward due to the flat character of the North Sea basin, the rivers were larger and led more debris with it, the vegetation went back to the eisnahen areas, the surface has been exposed to environmental influences stronger. During warm periods the sea rose and flooded or destroyed existing land and delta areas, the rivers carried less water and rubble, the vegetation stabilized the earth's surface. Characteristic of the Rhine-Maas Delta is the very strong influence of the glaciation in northwestern Europe during the Pleistocene glaciation, especially the Saale glaciation (see below).

During the cold periods, the south-western North Sea basin was on the one hand a replenishment point for scree from the Rhine (which was now draining parts of the Alpine ice sheet), but in the early Pleistocene it was still predominantly for the Baltic river system (Elbe, Weser), the scree brought in from the east by the Scandinavian ice sheet. During the cold ages, the flow of the Rhine was up to ten times higher than it is today. Since the North Sea basin is very shallow, the Pleistocene low-level deltas (cold periods) and high-level deltas (warm periods) are far apart. The current Holocene delta of the neo-warm period is a high-level delta and is therefore not located on previous low-level deltas, but on Pleistocene gravel plains . However, thin delta sediments consisting of short interstadials can also be found in these gravel. Old Pleistocene delta deposits can be found under the Pleistocene nondelta sediments. Only a few parts of the seaward Pleistocene low-level deltas of the Rhine-Maas system have been preserved.

During the Quaternary the area between the Middle Rhine and the Dutch-German border was raised, while the North Sea basin with the Netherlands sank. The dividing line between extensive sedimentation and extensive erosion also roughly coincides with the state border on the Rhine. River terrace series were created in the uplift area due to uplift and the alternation of warm and cold periods . In the subsidence area, the quaternary layer is up to 1000 m thick. From a geomorphological point of view, almost all of the Netherlands can be described as a delta plain.

Old Pleistocene

In northwestern Europe, the Old Pleistocene (approx. 2.6 mya - 780,000 years BP) is subdivided into the following five complexes:

Pre-Tegelen complex (Brüggen glacial period)
Tegelen complex (Tegelen warm period)
Eburon complex (Eburon glacial period)
Waal complex (Waal warm period)
Menap complex

In the Old Pleistocene, the Rhine tapped the Aare, which up until then had drained into the Saône , and pushed its catchment area into the Alps. The Meuse penetrated into what is now the upper reaches of the Moselle in the Vosges. Both events can be read from the changed sediment composition of the Pleistocene terraces below the current delta.

In the Middle Tegelen (about 2.1 mya) the coastline was similar to that of the Old Pliocene. In the area of the Rhine deposits (Eifel-Rur-North Brabant), however, there are now two separate areas that indicate a division of the Rhine in the area between Aachen and Cologne. Coming from the southwest, the Maas flows north of Aachen into the eastern arm of the Rhine. In the Younger Tegelen (about 1.9 mya) the concave coastline had been transformed into a convex one and extended far beyond the current coastline into the North Sea. The ice sheets in Scandinavia and in the area of the British Isles that formed during the cold ages were not in contact, the Rhine flowed into the sea roughly in the area of the Dogger Bank . The border between Rhine sediments and those of the Baltic river system run in an east-west direction at the level of the Zuiderzee south bank. Up until the Waal warm period (about 1.5–1.2 mya) the Baltic rivers (Elbe, Weser) expanded their deposit area to the south as far as the Lek and Waal. The rivers Rhine and Maas underwent significant changes: In North Rhine-Westphalia, the broad Rhine bed shifted to the east, roughly to its current position, in order to turn sharply west at Wesel . The Maaslauf only flowed into the Rhine in the southern Netherlands.

Middle Pleistocene

Braided River , typical type of river in cold climates. Makarora River and Lake Wanaka , New Zealand

Structure of the Middle Pleistocene (approx. 780,000–128,000 years before today) in the area of the Rhine-Meuse Delta:

The catchment area of the Rhine also enlarged in the Middle Pleistocene and worked its way into the area of the Alpine Rhine (before that the tributary of the Danube). During the penultimate glacial period, the Saale glacial period, the Moselle cut off the upper reaches of the Meuse.

After the Waal Warm Period, the supply of the Baltic river system stopped. In the young Cromer, the coastline was similar to today's, Rhine sediments covered almost the entire Netherlands north of the Waal. Meuse sediments can be found in the Maastricht-Eindhoven area, essentially west of the current course. During the Holstein warm period, Rhine sediments can be found in the area of the IJsselmeer and Gelderscher IJssel, the Maas flows into the Rhine around Arnhem.

The Saale glacial period brought the greatest advance of glaciers from the north to today's delta area. The southern border of the largest glaciation (Amersforter Stadium) runs right through today's delta area, for example, coming from Ipswich , via Haarlem, Utrecht and Nijmegen and on to Krefeld and Essen. The remains of the glacial activity that can still be seen are up to 100 m high terminal and compression moraines, which can be found above all in the Veluwe, in the Utrecht hills and near Nijmegen - between the Waal and the Maas. The Lower Rhine ridge is the continuation of the German Lower Rhine Plain. The terminal moraine walls still partially determine the extent of the current post-Pleistocene delta. In the preceding Elster glacial period, the ice sheet only reached the northern edge of the Netherlands.

Both during the Elster and Saale Glaciers, the north-flowing Rhine and Maas were diverted to the west by the ice edge. During the maximum state of the Saale cold time, the Rhine was already diverted at the edge of the ice near Düsseldorf, the Rhine and Maas beds merged roughly in the area of northern Limburg. To the west of today's coast, the Rhine flowed southwest through the current Dover Strait and the English Channel , to flow northwest of Brittany into the Atlantic. He had previously recorded the Thames and Seine . The continental shelf at that time was largely above the sea, the nearest shoreline retreated from Ireland to the south in the Bay of Biscay . During the Saale glaciation, but after the ice had retreated from the Netherlands, the Rhine broke through the terminal moraine walls near Düsseldorf to the north, left the present-day Rhine bed roughly near Wesel in order to advance further north into the valley of the Gelders IJssel and north of the Vechte to turn sharply to the west again. The Meuse remained south of the terminal moraines and flowed west in the area of the Merwede.

Young Pleistocene

The Young Pleistocene (approx. 128,000–11,650 years BP) is structured as follows in the area of the Rhine-Maas Delta:

Eem warm period , approx. 128,000–117,000 years BP
Vistula glacial period , approx. 117,000–11,650 years BP

The Vistula glacial period is divided into these three sections:

Early glacial, approx. 117,000–73,000 years BP
Pleniglacial (high glacial), approx. 73,000–14,500 years BP
Late glacial, approx. 14,500–11,650 years BP

This climatic level forms the last section of the pleniglacial:

Oldest Dryas , Stadial, approx. 18,000-14,500 years BP, cooler

The late glacial is divided into the following four climate levels:

Bølling , Interstadial, approx. 14,500–14,000 years BP, milder
Older Dryas , Stadial, approx. 14,000–13,900 years BP, cooler
Allerød , Interstadial, approx. 13,900–12,850 years BP, milder
Younger Dryas , Stadial, approx. 12,850–11,650 years BP, cooler

The course of the coast during the Eem warm period (based on Van der Heide 1965)

During the Eem warm period, the penultimate warm period, the sea level was sometimes higher than it is today. The sea had advanced far into the mainland, the coastline in some cases ran considerably further east than it is today. From the west the sea in the area of Noord-Holland and the IJsselmeer had penetrated far to the east and had flooded the Rhine valleys at that time. The Rhine, which had maintained its course from Wesel to the valley of the Gelders IJssel and through this to the north, flowed into the large bay in the area of the IJsselmeer east bank. The Meuse remained in its course in the area of today's Merwede. Flat deposits of the Meuse and Scheldt can be found in an area from South Holland to Zealand and Belgium.

The ice sheet did not reach the Netherlands during the Vistula glaciation. After the sea level fell, the coast followed a similar course as in the previous cold periods. The Rhine sediments show two large, separate main beds for the early glacial period:

The northern main bed: this moved first to the north through the valley of the Gelders IJssel, then to the west through the IJsselmeer and North Holland, and finally to the southwest, presumably to unite with the southern main bed in what is now the North Sea area. The northern main bed was abandoned during the pleniglacial.
The southern main bed: this branched off to the west in the area north of Wesel and then passed through what is now the central delta area. The upper section of the southern main bed ran further south at times: it already branched off to the west at Moers and passed through the present-day valleys of Niers and Maas to the west. It is unclear whether these two spatially separated areas of the upper southern main bed existed one after the other or (at least partially) at the same time. The Rhine course through the Nierstal probably existed up to the Allerod-Interstadial.

The Maas reached the southern main bed of the Rhine in the area of today's Niers estuary.

In the pleniglacial the sea level was about 120 meters lower than today. In the area of today's coastline, deep, late glacial valleys were created, which still influence the appearance of the coast and the course of the river today. Also in the pleniglacial, the sea level began to rise (but did not reach today's coast until after the Pleistocene). During the warm Bolling-Allerod interstadial of the late glacial, the river type changed : so-called braided rivers ( a river bed with several rivers, sedimenting, shifting frequently and unsystematically) became deeper, meandering streams (again short in the younger dryas Braided Rivers). Braided rivers are typical of all cold periods (permafrost, vegetation that is not very secure) and can also be found in cold regions today.

During the middle and late Vistula cold period, two important terraces were formed (not only) in the area of today's delta:

in the pleniglacial and in the late glacial the so-called "low terrace" was graveled (approx. 50,000-13,000 BP)
in the Younger Dryas and in the early Holocene, the so-called "Terrace X" was formed (also "Younger Dryas Terrace", approx. 13,000-10,000 BP)

The north-south intersection of the two terraces is near Rotterdam. Both terraces are covered with thick loamy deposits from rivers beginning to meander from the Allerød and Early Holocene periods (Wijchen member of the Kreftenheye formations). At the end of the Late Glacial (Younger Dryas) large parts of the Netherlands were covered with Aeolian sands (so-called deck sands) due to a dry and windy climate . There was extensive dune formation with up to 20 meters high, parabolic dunes that can still be seen in the landscape today and were the site of the first settlements. The orientation of the dunes shows prevailing wind directions from the southwest and north.

Aspects of development in the Holocene

Outline of the Holocene

The end of the last colder phase of the Vistula Ice Age (Younger Dryas) around 9650 BC marks the transition from the Pleistocene to the Holocene . The Holocene only consists of the Neo-Warm Period (also known as the Flemish Warm Period), the current warm phase. This warm phase is divided into five climatic stages based on the ascertainable vegetation development:

Preboreal : approx. 9650–9000 BC: reforestation, rapid rise in temperature
Boreal : 9000–6000 BC: further warming
Atlantic : 6000–3000 BC: Holocene climatic optimum, summer temperatures 2–3 ° C higher than today
Subboreal : 3000–500 BC: cooling, agriculture
Subatlantic : since 500 BC: more humid and cooler climate

Some of the climate levels are summarized as follows:

Early Holocene: Preboreal and Boreal, approx. 9650–6000 BC
Middle Holocene: Atlantic and Subboreal, approx. 6000–500 BC

Elements of the Holocene Delta

The Oude Rijn near Bunnik. The Oude Rijn was part of the main arm of the Rhine Delta between about 3000 and 850 BC

The Rhine-Maas Delta can be subdivided into areas according to the prevailing sediment types, some of which are strongly interlinked in the marine area:

Area without marine deposits:
- Area of fluvial deposits: characterized by meandering rivers, 1–2 km wide river beds and comparatively narrow flood plains
Areas only with or also with marine deposits: beach ridges and coastal dunes as well as a strip of land reaching around 25–30 km inland, in the area of the Haringvliet protruding far to the east, including the Biesbosch
- Areas with a strong fluvial influence (also called “perimarines” area): Narrow, weakly meandering, straight anastomosing river belts with large dike breakage cones. The large floodplains contain thick layers of peat
- Areas of deposit of tides, estuaries and lagoons: peat-covered tidal deposits of subboreal and Atlantic ages
- Beach ridges and coastal dunes: can also be found in the south-west and north, but only closed in Holland

Since the Middle Ages, large areas of peat have been mined by humans, which later resulted in many lakes, most of which were drained from around 1450. The land is therefore particularly deep at these points (e.g. the area between Rotterdam and Amsterdam).

The coastline itself can be broken down as follows:

southwest coast: large tidal bays, including the Scheldt estuaries
Dutch coast: no tidal bays, wave movements are the dominant process
northern coast: islands, tidal bays, Wadden Sea

Main factors

The following main factors have been identified for the development of the Holocene Rhine-Meuse Delta and the Holocene river and coastal plains:

The moon causes the tides , which in turn are a factor in delta and coastal development

Morphology of the Pleistocene land surface: broad valley of the Late Softening Period, bounded in the north by terminal moraines. The location and size of the Pleistocene valley had a major influence on the formation of the Holocene delta, as the sea first penetrated into the mouths of the late Pleistocene river valleys near Rotterdam and Alkmaar and the course of the Holocene rivers was mostly limited by the higher Pleistocene plains.
Sea level: Eustatic sea level rise: caused the rivers to rise, which in turn made avulsions possible in the first place as the rivers changed from incisive to sedimenting rivers. Both the delta and the area of possible avulsions migrated eastward as the sea level rose. This eastward migration was stopped or slowed down around 4000 BC by the Peel Edge Fault.
Neotectonic movements: isostatic subsidence of the land area, tectonic subsidence of the North Sea basin and the Rur trench. The Zentralgraben, a tectonic ditch complex, stretches in a north-west-south-east direction from the North Sea Basin via Holland and the central delta area into the Cologne Bay: its most important tectonic structures are: Rurgraben, Roer Valley Graben , Peel-Horst and Venloer Graben. The boundary line between the first two, the peel boundary fault , represents the most active fault .

In 1992 the earthquake of Roermond struck her with a magnitude of 5.9 on the Richter scale . In the last 14,000 years the Rurgraben sank about two meters. The lowering process increases the (discharge) gradients of the rivers crossing the fault line and gives them a corresponding gradient advantage. At the same time the peel eyrie rises. Its elevation could have led to the diversion of the Nederrijn to the north between Rhenen and Amerongen. The Nederrijn shifted there in the direction of the Saalischer terminal moraine and even cuts it at Rhenen. The Rurgraben, on the other hand, could have favored the leaving of the late Pleistocene valley by the Rhine near Gouda. It can also be observed that there were frequent avulsions in the area of the peel clumps.

Changes in runoff volumes and sediment loads: Two main trends can be identified:

At the beginning of the Holocene there was a decrease in runoff due to the decrease in permafrost and the increase in vegetation, which led to a reduction in river beds.
The flow rate increased again from around 800 BC, and so did the sediment load since around the turn of the century, also due to human influence (clearing in the catchment area of the Rhine and Maas, stronger slope erosion). The discharge peaks increased significantly. This second main tendency led to larger meanders, more river beds and more avulsions (maximum around the turn of the ages). The result was a completely new delta network around 300 AD.

River flood deposits: River floods increased sharply after 500 BC. Abandoned river beds were re-occupied.
Peat formation in the coastal plain behind the beach ridges, caused by a rapid rise in groundwater in the wake of rising sea levels. At the turn of the ages, peat formation ended.
Coastal developments: The presence of Pleistocene sands on the flat North Sea floor led to the formation of beach ridges and coastal dunes, which played an important role in the preservation of the Holocene deposits in the lagoons behind the beach ridges .
Springtidenhub (about two meters): greater influence in Maasästuar than in Rheinästuar because runoff and sediment of the Meuse had to oppose the tide less.
Influence of humans: since around 1100 AD, the dikes of rivers and damming of smaller delta arms, reduction of the sediment areas to the flood plains of three remaining delta branches (Waal, Nederrijn, IJssel)

Aggradation

Aggradation by rivers occurs when sedimentation outweighs erosion. Aggradation leads to the formation of natural dykes ( dam bank river ) and to the elevation of the river bed above the surrounding flood surface due to sedimentation on the bank and at the bottom of the river bed. With the onset of aggradation in the early Atlantic (6000 BC), the formation of the Holocene Delta began when the sea level reached the present coast, thus reducing the runoff gradients of the rivers. The sea first penetrated the Pleistocene valleys (in the north west of the IJsselmeer, in the south in the area of southern South Holland / northern Zealand). With the further rise in sea level, the runoff gradients of the rivers also decreased further inland, so that the area of the aggradation, i.e. the eastern border of the Holocene delta, also migrated steadily inland. The superficial interface between the pleniglacial terrace and the Holocene deposits was at the time of the onset of the aggradation around 6000 BC at the level of Rotterdam and quickly migrated eastwards. This shift slowed down somewhat at the tectonic height and uplift zone of the Peel Horst. Later, the relocation of the interface slowed down, presumably due to the ever decreasing sea level rise. Around 500 BC the eastern border of the Holocene deposits ran around Millingen , today it is near Emmerich .

Avulsion

The key process in the paleogeographical evolution of the Rhine-Meuse Delta is the avulsion, that is, the short or long-term, complete or partial abandonment of an existing river bed or river belt in favor of a new one. For the period of the last 5000 years 91 avulsions could be localized and dated. 30 of these are considered significant. A distinction is made between complete and partial avulsions. An avulsion is complete when the old river bed - whenever - is abandoned. A persistent partial avulsion is a bifurcation (river belt division). In 50% of cases, the old and new river belt coexisted for more than 200 years (gradual avulsion). Nodal avulsions are more than two avulsions in (almost) the same place.

The most important parameters are: the frequency of avulsions, the duration of an avulsion and the duration of a river belt (interavulsion period). On average, an avulsion occurred every 500 years. The average duration of an avulsion process was about 325 years (less than 200 to over 1000 years). The average lifespan of all 206 identified river beds is around 1000 years. The river bed with by far the longest existence is that of the Oude Rijn with around 4500 years, the one with the shortest span is that of the Spijk with around 310 years.

Aggradation is often a prerequisite for natural avulsion. The concrete starting point of a natural avulsion was probably always the break of a dike created by the river itself. Especially in the period from 4000 to 2000 years ago, many avulsions seem to be related to tectonic movements of the Peel Horst and Roer Valley Graben. The comparatively rapid subsidence of the area southwest of the Peel Boundary Fault created new backfill space and preserved an effective flow gradient for the rivers. All of this increased the incidence of avulsions on the Peel Boundary Fault.

The most important factors for avulsions are the rate of sea level rise, the size of the runoff and the siltation of river beds, but also human influence:

Due to human influence, natural avulsions only existed until around the year 1000.
The river shifts caused by the construction of canals or watercourses are also known as avulsions. The most important artificial avulsions are the Pannerdens Canal (1707), the Neue Merwede (1851–1860) and the Bergsche Maas (1904).

Without human influence, there would have probably been some natural avulsions in the last few centuries. The current river beds have existed longer than they would have existed without humans. Artificial dykes, groynes and dredging maintain and fix river belts and prevent avulsions. In the future, increased efforts will be necessary to maintain this situation.

Main avulsions:

Approximate time (year)	New river bed	Old river bed	Closest place	Remarks
1904 AD	Bergsche Maas	Afgedamte Maas	Veluwe (German: Well )
1421 AD	New Merwede	Waal (Merwede)	Hardinxveld	Partial avulsion caused by the Elisabeth flood, then narrow tidal bays and creeks, dredging 1851–1860
1250 AD and 1060 AD	Afgedamte Maas	Alm-Werken and Oude Maasje	Rijswijk and Hedikhuizen
325 AD	Waal (from Tiel)	Linge	Tiel
300 AD	Oude Rijn (from De Meern)	Heroine	De seas
250 AD	Geldersche IJssel	Nederrijn	Arnhem	Partial avulsion
145 AD	Hollandse IJssel	Hollandse-IJssel-Linschoten	Montfoort
At the turn of an era	Lek	Kromme-Rijn-Oude-Rijn and Ravenswaay-Hagestein	Wijk bD and Hagestein
50 BC	Waal (from Lobith)	Ressen	Lobith
50 BC	Maas (from Nederasselt)	Huisseling demen	Nederasselt
210 BC	Linge	Real eld	Ochten
300 BC and 100 BC	Vecht	Oud-Aa and Angstel	Breukelen and Loenen	300 BC partial avulsion
550 BC	Nederrijn	Ressen	Lobith
1050 BC	Kromme Rijn	Houten	Wijk bD

River patterns and types

The increase in the average temperature in the preboreal and boreal areas led to an increase in vegetation and a decrease in the maximum discharge and sediment load. In the latter, the proportion of fines increased. Since then, the predominant type of river in the area of the pleniglacial terraces has been the incising and meandering river.

The development of the delta was associated with changes in river types and patterns. One can observe an inland, spatial progression of river patterns. This process can be represented in a space-time model with four zones. In this model, zone 1 is the easternmost and zone 4 is the westernmost, so the zones extend in an east-west direction. These zones migrated eastwards with the sea rise, which is why zones 3, 2 and 1 are found under zone 4 (etc.). The further west you go, the weaker the runoff gradient of the rivers - this fact also means that the rivers to the west increasingly tend towards the straight river type. Zones 2 to 4 correspond to the central delta area.

east	Zone 1	Pleistocene Terraces	between Emmerich and Bonn, meandering, cutting and eroding rivers with natural dykes		easily erodible sand deposits, still relatively high gradient
	Zone 2	Holocene Terraces (Holocene Delta)	young and flat areas, rivers strongly meandering, lateral sedimentation (accretion)	anastomosing flow type, aggradation	easily erodible sand deposits, still relatively high gradient
	Zone 3	Holocene Terraces (Holocene Delta)	weakly meandering, natural dykes	anastomosing flow type, aggradation	predominantly thick, resistant layers of clay and peat, hence narrow and deep rivers
west	Zone 4	Holocene Terraces (Holocene Delta)	tidal, straight river type, islands	anastomosing flow type, aggradation	predominantly thick, resistant layers of clay and peat, hence narrow and deep rivers

This scheme has existed at least since 6000 BC and is only valid for the central areas of the delta, as easily erodible sandy deposits predominate in the eastern, southern and northern peripheral areas. Strongly meandering rivers with lateral aggradation or increased dike erosion dominate these marginal areas.

River systems

The investigated river bed fragments and the river courses derived from them were grouped by Berendsen / Stouthamer into seven river systems (see section research methods ). The criteria for grouping these river systems were age, area of origin, flow rate and direction of flow. The following river systems were defined:

Benschop river system
Utrecht river system
Krimpen River System
Meuse river system
Est river system
Graaf river system
Linschoten river system

Development in the Holocene

Until about 250 BC

Due to the melting of the ice sheets during the Vistula Glaciation, the sea level rose very quickly in the early Holocene, by about 1 meter in 100 years. The coastlines and thus the estuary areas of the rivers have been moved further and further back. The British Isles on the opposite side of today's delta were separated from the mainland. The later slowing down of this increase is also due to isostatic lowering. With the rise in sea level, there was also a constant increase in the groundwater level.

The global warming at the beginning of the Holocene also caused a change in river patterns: the Braided Rivers of the Younger Dryas in the preboreal became deeply cutting, weakly meandering or straight flowing rivers. The flow rates decreased sharply, and there were no river shifts. There were numerous river courses throughout the delta area. This oldest Holocene river system existed between about 7800 and 5800 BC. Due to the rise in sea level and the resulting rise in groundwater, these rivers were later filled with peat.

In the first centuries of the Holocene there was no delta formation due to the incised rivers. The formation of the delta only began between 7000 and 6000 BC with the aggradation in what is now the coastal area, the sedimentation now outweighed the erosion. The aggradation and formation of the current delta was only made possible by the rise in sea level, which lowered the runoff gradient of the rivers. The developing Early Holocene Delta was in the area of the Younger Dryas delta. The west of the Early Holocene Delta, near today's coastline, was eroded by later tidal systems.

The Netherlands around 5500 BC: light green tidal areas (Wadden Sea etc.), dark brown marshland, clay and loam areas. Coastline between Zealand and North Holland to the east, at Texel to the west than today. Numerous river divisions in the marshland, Rhine and Maas essentially separated

The relatively strong rise in sea level caused the aggradation area, ie the area of the delta formation, to expand eastwards from 6000–2000 BC. With this, the border between the Holocene deposits and the older Pleistocene terraces also moved eastward. Around 4000 BC the eastern expansion of the Holocene delta at the Peel Horst, a tectonic uplift zone, was slowed down, and then continued again, despite lower sea level rise. Avulsions occurred in the area of the Holocene Delta. In the area of the Pleistocene deposits neither aggradation nor avulsions took place, there the Early Holocene beds were fixed until extensive Holocene deposits set in in the Pleistocene sediments. With the continuing rise in sea levels, the decrease in runoff and the increase in vegetation, the rivers became narrower and slower flowing between 5500 and 2000 BC. Around 5000 BC beach ridges were probably formed west of today's coast, which were later eroded again by the rising sea.

The Benschop river system existed between 5650 and 3400 BC. It stretched between Gorkum / Vianen and Rotterdam / Gouda. The main arm of this system emptied into a tidal basin north of Rotterdam that stretched from The Hague to Schouwen. This basin probably resembled today's Wadden Sea and was located in the area of the late glacial river valley, where the sea could penetrate well. Around 4550 BC this main arm shifted from the late glacial valley to an area of late glacial Aeolian sands. The Benschop river system was a complex of anastomosing rivers in straight beds and with numerous large dike breakage cones. From the main stream, numerous small river branches branched off to the southwest, which flowed into the Meuse estuary and were probably created after dike breaches. Since they were mostly abandoned around 4000 BC, they can also be viewed as "unsuccessful avulsions". The course of the Meuse at that time can hardly be reconstructed.

The tidal and estuary deposits that occur in the area behind the beach walls were formed in two transgression phases during the Atlantic (6000-3000 BC, Calais transgression) and the sub-Atlantic (since 500 BC, Dunkirk transgression). In the meantime, in the sub-boreal region (3000–500 BC), extensive layers of peat formed behind the beach walls where the beach wall coast had closed (Holland).

The Netherlands around 3850 BC: Loss of land, expansion of the tidal and marshland areas, relocation of the main arms of the Rhine to the north

Around 3300 BC there were large sea bays in the area of the Pleistocene valley paths in Zealand-South Holland and North Holland-IJsselmeer. At this point in time, during the first phase of transgression, the oldest preserved beach ridges were formed, especially between these two bays , in the north the forerunners of today's West Frisian Islands . They formed partly to the east and partly to the west of today's coast. To the east of these walls, a state similar to that of the Wadden Sea developed with tidal sands, mud plains and tidal creeks. The slowed down transgression no longer eroded these walls, but instead created new beach walls and coastal dunes to the west (!) Of the older walls. This ended the phase of retrogradation (shifting the coastline or the delta front towards the land) and began a progression phase (shifting the coastline towards the sea, especially between The Hague and Alkmaar) that lasted until the turn of the century . Between 3000 and 2500 BC the character of the coast changed from an open coast to a coast with a chain of walled islands.

As early as around 3550 BC, a significant avulsion, possibly due to a dyke flood cone, had occurred near Wijk bD, which led to the Benschop course being abandoned around 3400 BC and the Utrecht river system being formed. This system mainly consisted of the rivers Werkhoven and Oude Rijn, both of which were initially just streams or small rivers. Despite many avulsions, the Utrecht river system initially drained into the Leiden estuary. Around 3300 BC there were extensive river deposits (delta areas) roughly between the Nederrijn-Lek and Maas, partially interspersed with Aeolian dunes from the Younger Dryas period.

The Netherlands around 2750 BC: Land reclamation, some tidal areas have become marshland, enlargement of the beach wall areas, shifting of the Rhine divisions to the east, many lakes and tidal creeks in the area of the former bay in the north with the prominence of Oer-IJ / IJ, approach of the Meuse and one Arm of the Rhine

Remarkably, the Oude Rijn did not run in the area of the late glacial valley, but north of it. From 3200 BC beach wall complexes also formed in the area of the Oude-Rijn estuary. The Oude Rijn flows between Woerden and Alphen into a tidal pool behind the beach walls. Around 3000 BC the Oude Rijn became the largest arm of the Rhine. Several smaller rivers branched off to the southwest from the Oude Rijn around 2500 BC. They were of the straight anastomosing type and flowed into the Maas estuary near Rotterdam, which, however, was probably still very small at that time.

The beach wall coast began to close around 2000 BC, and was closed by 1700 BC. However, three tidal bays remained: the Bay of Alkmaar (Vecht, Angstel), the Bay of Leiden (Oude Rijn and others) and the Bay of the Meuse west of Rotterdam. The Meuse estuary was the outlet of the Meuse throughout the Holocene, and then increasingly also for various branches of the Rhine. Overall, the palaeographic reconstruction is partly not possible for the coastal area because many of the deposits were eroded. The wide beach wall coasts offered relative protection against the encroachment and intrusion of the sea. In the coastal plain behind the beach walls there were large bogs and lagoons. River floods and deposits led now, between 2000 and the turn of the ages, to the formation of clay and peat layers, which were interspersed with numerous small sandy, often branching river beds. The peat formation was very extensive especially up to 1000 BC and then decreased.

The Linschoten river system existed between 2000 BC and the turn of the times and carried off part of the Oude-Rijn river. Around 1550 BC, another major avulsion occurred, also at Wijk bD, which led to the enlargement of the Linschoten run and the reduction of the Oude-Rijn route between Utrecht and Woerden. Around 1000 BC, after another avulsion, again at Wijk bD, at the expense of the Houten-Lauf the Kromme Rijn was created. The increase in the discharge of the Oude Rijn around 1000 BC is possibly related to the formation of the Kromme-Rijn-Lauf. The Houten-Lauf continued for about 500 years and then slowly silted up. Shortly after 1000 BC, the Kromme-Rijn-Oude-Rijn route was the main arm of the Rhine Delta.

The Netherlands around 500 BC: Land reclamation, expansion of the marshland (Zealand, Rhine-Maas Valley, IJsseltal), almost closed beach wall coast, estuaries (Scheldt, Maas, Oude Rijn, Oer-IJ), formation of an inland lake in the north, new arm of the Rhine to this See (Vecht), shifting of the Rhine divisions to the east

Around 1700 BC the coastline had approximated to today's, the beach wall coast was closed almost everywhere. However, smaller estuaries still existed at the mouths of the larger rivers: the Oosterschelde, the Maas estuary near Rotterdam and the estuary of the Oude Rijn near Leiden (Leiden estuary). The eastern half of the large northern bay had become an inland body of water (later the Zuiderzee), but in the area of the IJ it was connected to the sea like an estuary. The extensive peat formations also covered the western river sediment area. Today's West Frisian Islands were still connected to the land. Around 1200 BC the Oude Rijn had built a delta into the North Sea at its confluence, which indicates a high level of water and sand drainage.

From 850 BC onwards, numerous rivers emerged in the central delta area, heading towards the increasingly important Maas estuary, while the Leiden estuary (= the estuary of the Oude Rijn) lost its importance. Krummer Rhein and Oude Rijn steadily lost their runoff, both silted up more and more. Around 700 BC an avulsion near Utrecht led to the formation of the Vecht, which led part of the water from the Oude Rijn into a tidal basin near Velsen , which was an outgrowth of the IJsselsee. The Vecht was the northernmost arm of the Rhine and developed its own delta.

From 250 BC to the 11th century

Between 250 BC and 350 AD, important changes occurred in the river network: Avulsions created the Nederrijn, Lek, Linge, Oude Maasje, Waal and (Geldersche) IJssel (in a pre-Holocene Rhine main bed between the Nederrijn and the Zuiderzee), as well as the lower reaches of the Dutch IJssel (below Montfoorts ). After the formation of the Nederrijn and Waal, many other rivers were abandoned and the Waal gradually became the main arm of the Rhine.

The Netherlands around 50 AD: Loss of land, estuarine formation. Junction of the IJssel, opening of the Flevo lake to the sea and closure of the original IJ. The increasingly strong western arms of the Rhine make the Maas estuary the main mouth of the Rhine; formerly the confluence of the Meuse and today's Waal.

Settlements on the main arm of the Rhine in Roman times

From around 50 BC, the main strands of the Utrecht System and the Oude Rijn shifted to the southwest. Reasons for this were the landings there due to increasing floods and sediment loads, the enlargement of the Meuse estuary due to coastal erosion with increasing tidal influence, and possibly tectonic movements in fault zones. The resulting gradient advantage towards the Meuse estuary made the rivers draining there from the Utrecht system gradually stronger, while the Oude Rijn and Leiden estuary lost their importance.

In Roman times the Oude Rijn was the border river of the Roman Empire. The Romans influenced the course of the river locally by building canals. The Vecht silted up around the turn of the century, but gained in importance again with the siltation of the lower reaches of the Oude Rijn. The later Zuiderzeebucht was still an inland waterway and is called Lacus Flevo (Flevo Lake) in the Roman sources.

A Drusus canal that cannot be located is often mentioned in the sources . This hydraulic engineering measure is probably related to the Drusus migration through the Flevo Lake along the North Sea coast around 12 BC. Together. In order to increase the flow to Lake Flevo, Drusus could have built a partial dam over the Waal, which would have pushed more water into the Nederrijn or the IJssel. According to another thesis, this measure supplied the Vecht, which is at risk of being silted up, with more water. The Drusus Canal could also have been a real short canal between the Rhine and the IJssel. It used to be believed that the bifurcation of the IJssel was only created through the Drusus Canal. The stretch from Westervoort to the confluence of the (old) Issel with the IJssel near Doesburg is still called Drususgracht. The Romans actually built a canal between the Oude Rijn near Leiden and the Ostium Helinium near Schiedam . The remains of the canal that still exist today are called the Vliet .

The Netherlands around 800 AD: massive land losses, enlargement of the northern bay, temporary whereabouts of a march bar between the Maas estuary and the Zeeland lost area

The growth of the Maas estuary and its increasing importance for the development of the delta were promoted by the storm surges between 50 AD and 700 AD. Also in the area of the Maas estuary - in contrast to the Leiden estuary - the tidal influence was stronger than the sediment input from the tributaries.

Between 100 AD and the early modern period there was extensive erosion of coasts and coastal areas (beach ridges and peat plains), which only declined again between 500 and 700 AD. There were large losses of land in the area of the West Frisian Islands and in the southwest (Zealand, Scheldt estuary). The Flevo lake (called Almere or Eemmeer ) enlarged. The later IJ (in the area of today's North Sea Canal) was still a southwestern protuberance of the Almere. After 500 AD, the coastal peat formations were also largely eroded by marine ingression . In the north and in Zealand there were tidal bays that worked their way through to Lake Flevo in the north, which as the Zuiderzee had become a bay again. The Maas and Scheldt estuaries also continued to grow. The Westerschelde and Haringvliet (also called Westerleek ) were created by 500–700 AD at the latest . The salt marshland, especially on the Scheldt estuaries and north of the Zuiderzee, expanded . The main channels of the Rhine continued to shift to the Maas estuary (also known as Brielse Maas ). The confluence of the Meuse and Rhine was called Masamunda or Ostium Mase (Dutch Maasmond ) in the Middle Ages .

By 950 AD, all of today's rivers existed, and many of the older rivers were completely silted up. After the decline in importance of the Oude Rijn, the Vecht had grown again and now led off the main drain of the Oude Rijn (Kromme Rijn). Around 1000 AD, sea bays were created after storm surges, connecting the Maas estuary with that of the Scheldt, neighboring to the south.

11th to 15th centuries

Human influence increased enormously from 1100 AD. The delta rivers were diked until around 1300 AD. Furthermore, numerous rivers and creeks were dammed, which meant the death blow for the old rivers. The number of arms of the Rhine was reduced to three (IJssel, Nederrijn, Waal). The most important dammings are: 1122 AD: Kromme Rijn (thus also Oude Rijn and Vecht), near Wijk bD, diversion of the water into the Lek, which had grown larger in the centuries before, around 1230 AD: Werken, 1250 AD: Albblas, um 1250 AD: Oude Maasje, 1285 AD: Dutch IJssel, 1307 AD: Linge, 1331 AD: Gedempte Devel and 1331 AD: Oude Waal.

The Linge, originally a tributary of the Waal along its entire length, was transformed in its part below Tiel into a specially dammed, straightened drainage ditch. Above Tiels, the Linge has remained a relatively natural body of water with meanders and flood plains, despite the damming.

The Nederrijn was usually only called Rijn (Rhine). In a document of Friedrich Barbarossa from 1165 u. a. the construction of a flood canal from the Nederrijn through the Gelderse Vallei to the Zuiderzee. However, the instructions in the document were not implemented.

A canal called the Vaartse Rijn was built from Utrecht to the Lek in the 12th century.

The dikes of the High Middle Ages made it possible to drain and dismantle the large peat areas in the west. The peat served as fuel and salt could also be extracted from it. Due to the high groundwater level, the peat mining areas soon turned into lakes, which were enlarged by storms. The Haarlemmer Meer and the Leidse Meer, which were connected to the Almere by different bodies of water, developed into the largest moorland lakes in Holland. Many of these lakes were pumped dry, especially between 1600 and 1900. Steam engines were used for the first time in 1852 when the Haarlemmermeer (now the location of Amsterdam's Schiphol Airport) was drained.

After the damming of the Oude Rijn, coastal formation processes at the mouth of the Oude Rijn closed the Leiden estuary and the mouth of the Oude Rijn disappeared. The delta of the Oude Rijn in the North Sea has been eroded. The tidal delta was eroded and its sands led to the formation of the so-called younger dunes along the coasts, which formed bars up to 40 meters high. The Waal became the most important arm of the Rhine, took in both the Lek and the Maas and drained through the tidal bay of the Maas estuary (Brielse Maas) into the North Sea. Between 1200 and 1500 AD the Zuiderzee reached its greatest extent. Between the Oude Rijn and the Leidse Meer there were numerous connections going back to priele (Aa, Heemswatering, Does, Zijl, Mare). These represented a particular danger, as the Leidse Meer was connected to the Zuiderzee via the Haarlemmer Meer and so the influence of the sea (tides, floods) could have an effect. In these waters, the water could flow in both directions, depending on whether the pressure of the Rhine water or that of the Zuiderzee was greater. The entire area at Oude and Kromme Rijn was called Rijnland.

The Westerschelde was created in the
1st millennium AD

The estuaries widened during storm surges and river floods and became smaller through siltation and drainage. Parts of the islands were polded in in the High Middle Ages, for example in the south of the Maas estuary Voorne and Putten and in the east the Zwijndrechtwaard northwest of Dordrecht .

From Dordrecht, the Merwede Current, which was already heavily influenced by the sea, flowed north around the Zwijndrechtswaard, first to Oostendam to the north (today's southern half of the Noord), then to the southwest to change its name back to Waal (in the area of today's creek called Waal between Oostendam and Heerjansdam ). At Oostendam, an initially insignificant connection branched off to the north to the nearby Lek (today's northern half of the Noord), which after the closure of the Waal near Oostendam was more important and also called Merwede (the Waal section between Oostendam and Heerjansdamm was dammed at the latest in 1332). The Lek was also called Merwede (or "Merwe") in its lower reaches. The name Merwede applied to the current section of the New Maas (from Vlaardingen) - Noord - Merwede, since the 11th century.

Also at Dordrecht, the Dort branched off to the southwest (today's beginning of the Oude Maas), which only a little later flowed into the Maas tributary Dubbel at Dubbeldam (today's Oude Maas). The Dubbel led the Dortwasser back into the Waal west of the Zwijndrechtswaard (also today's Oude Maas). This flowed together with the Meuse on what was then the eastern edge of the island of Putten (near today's Goidschalkxoord , then Place Puttensteyn), and the resulting stretch of river called Maas (in the area of today's Oude Maas) flowed into the Maas estuary a little later across from Vlaardingen. The Lek-Merwede (today's Neue Maas, see above) flows into the immediate northern neighborhood. The sections of today's Oude Maas between Dordrecht and Rotterdam were called Dord - Dubbel - Waal - Oude Maas.

The Meuse forked into two arms at Heusden , one of which went north (today's Afgedamte Maas), was also called the New Maas and flowed into the Waal at Woudrichem; the other arm, which has now disappeared, was also called the Oude Maas and flowed westwards through the “Great South Holland Waard”, a uniform polder area that was quite extensive for the time. Around the middle of today's Biesbosch, the Dubbel, which flows southwest of Dordrecht into the Waal (today's Oude Maas), branched off to the right from this former Oude Maas (see above). The Maas division at Heusden and Bokhoven into the western and north-western arm already existed in antiquity. The beginning of the western arm of the Meuse on the eastern border of the South Holland Waards was dammed around 1270 and shortly afterwards (first mentioned in 1296) it was probably called “Oude Maas”, the north-western arm “New Maas”. However, the northwest arm of the Meuse may be older than the western arm. This flowed slightly south of today's Bergse Maas (remnants that still exist today are called Oude Maasje), then in the area of Amer and Biesbosch towards north-northwest (remnants between Maasdam and Westmaas ), from around Goidschalxoord roughly identical to today's course, north of Spijkenisse flowing into the Meuse estuary.

The northern border of the so-called Maas estuary (since the main flow of the Rhine was relocated to it, it actually functions primarily as a Rhine estuary) can roughly be described as the course of the New Waterway and the Scheur, the southern border with that of the Brielsche Maas. The entire Rotterdam port facilities between Rotterdam via Europoort and the Maasvlakte are located in the area of the former "Ostium Mase", the "Helinium" of the Romans.

The South Holland Waard was bounded in the north by the Merwede-Dord-Dubbel line and in the east by the New Maas. In the south the Waard border extended from Heusden via Geertruidenberg further into the area of today's Hollands Diep, the place Maasdam attests to the location of the western border of the Waard.

Numerous meanders were cut off from around 1350 and into the 20th century. This led to an increase in the flow velocity and a decrease in the risk of flooding.

15th to 17th centuries

The numerous storm surges of the Middle Ages also led to the further enlargement of the Maas estuary. The so-called Elisabeth flood in 1421 led to the formation of a huge estuary between the Maas and Scheldt estuaries in the area of today's Biesbosch (see below). The river beds there were eroded, the Waal became more important and withdrew more and more water from the Nederrijn.

The St. Elisabeth flood (November 1421) inundated large parts of the delta area. The bay of the Haringvliet pushed deep inland to the east, creating the Hollands Diep, which initially occupied much larger areas than it does today. The mouth of the Waal into the sea was initially at Gorinchem. Large areas could no longer be reclaimed from the water, especially the Great South Holland Waard. The Maas between Heusden and Putten as well as the Dubbel above Dordrechts should be mentioned in particular. Today's oxbow lake between Maasdam and Westmaas and the Oude Maasje south of today's Bergse Maas are the last remnants of this submerged mass flow. From then on, Dordrecht was on an island between Hollands Diep in the south and Merwede-Waal in the north. 72 church villages were destroyed, of which 23 were never rebuilt. The flood of 1421 permanently changed the hydrogeographic status of the delta and led to numerous name changes for individual lower sections of the river. In many ways, however, the name history outlasted natural history.

In 1437, a little above its mouth, on the border between the diocese of Utrecht and the Count's Dutch Amstelland (still provincial border today), the Vecht near Hinderdam was dammed. In 1439 the rest of the destroyed western Meuse arm was dammed up at Westmaas. That was also dammed.

Hendrick Avercamp (1585-1634), "IJsvermaak". Such paintings are only known from the early modern "Little Ice Age".

Despite the immediate proximity of the new Hollands Diep bay at the Meuse fork near Heusden, the Meuse water now mainly flowed into the north-western arm (now known as the Maas) (today's Afgedamte Maas) and from there into the Merwede. Its water now flowed to a large extent into the Hollands Diep between Gorinchem and Dordrecht and thus led to the creation of a delta in the delta, the Biesbosch (Binsenwald), also known as Bergse Veld (Bergsches Feld). With the formation of the Hollands Diep, the estuary base of the Waal and the Merwede was moved forward, therefore, and because of the siltation of the river beds, more and more water flowed into the Waal at the division of the Rhine and less and less into Nederrijn and IJssel. To the west of Heusden, a new arm of the Meuse was created, called the Bergse Maas, which flows into the Hollands Diep via the Amer tidal bay. However, it carried much smaller amounts of water than the river leading to the Waal. At the end of the 15th century the two loops of the Meuse were pierced at Heusden (at Veluwe (German: Well ) and at Neder-Hemert ).

The eastern delta areas around 1645

The name Oude Maas was transferred to the Dord-Dubbel-Waal line, the names Dubbel and Dord disappear. The Dordtse Kil, initially called Vaart or De Kil, was built between Dordrecht and Hollands Diep. The stretch between Dordrecht and Heerjansdam (formerly called Dord or Dubbel) was still called sometimes Maas, sometimes Merwede for a long time. The section of the Merwede between Dordrecht and Krimpen am Lek was increasingly called Noord, the name prevailed in the first half of the 18th century (first mentioned in 1537 as "'t noort diep"). Due to the flow of large amounts of water from the Merwede into the Hollands Diep, the Noord received less water, and numerous sandbanks and river islands, called "oord", formed. The Noord may have got its name from this "oord". But: seen from central Dordrecht, the Noord is a stretch of river flowing north, and “North” means “Noord” in Dutch. The Merwede section from the confluence with the Lek was called the New Maas from around the 17th century. Land reclamation was carried out in the Maas estuary and the island of Rozenburg is being created. The Brielse Maas / Brielse Diep was created on the southern edge of the bay, as an equivalent to the New Maas migrating west on the northern edge. A branch of the New Maas north of Rozenburg was called Scheur.

18th century

In the 18th century, the last primeval forests on the floodplains disappeared to make way for agriculture and settlement. From the Oude Rijn, a canal was cut along its old course through the chain of dunes to the North Sea. The Spui was created through the island of Putten between Oude Maas and Haringvliet . The Nederrijn was still mostly just called Rijn.

The lek at Jaarsveld. The Lek originated between 250 BC and 350 AD and took over the entire amount of water of the Nederrijn from 1122 AD

Since the late Middle Ages, the Nederrijn has shown a tendency towards silting, and without human intervention the Nederrijn-Lek and (Geldersche) IJssel would probably have run dry. This finally prevented the construction of the Pannerdens Canal in 1707 AD , which was also built to facilitate navigation. Since then it has ensured the flow of Rhine water into the bed of the Nederrijn. With the breakthrough of this canal, the distribution of the Rhine water to the three main arms of the delta (6/9 Waal, 2/9 Nederrijn, 1/9 IJssel; see chapter water distribution and water volumes ) was regulated in intergovernmental agreements . The old Rhine east of Pannerden was dammed. The Pannerdens Canal lies between Pannerden and Peppelgraat and was initially called "Den Nuwe Rijn" - New Rhine. When it was built, the beginning of the Nederrijn at Schenkenschanz was cordoned off, the remaining oxbow river between Elten and Loo is called Oude Rijn, De Jezuitenwaai or De Keel (today partly in the area of the Dutch-German border). Thus, the division of the Rhine shifted about seven kilometers down the Waal. The Waal section above the Pannerden Canal was initially called Boven Waal, the section below Beneden Waal.

With the breakthrough De Pleij near Weestervoort , the junction of the IJssel from the Nederrijn was shortened in 1773–1776. Without this intervention, the flow of Rhine water into the IJssel would have been interrupted by silting. The Bijlands Kanaal was laid out in 1775 between Schenkenschanz and Gendt (municipality of Lingewaard ) . It represents a straightening (and partly a slight northward relocation) of the Waal in the area of the division of the Rhine. Between Warbeyen or Griethausen and Keeken there are still remnants of the former course of the Waal, today called "Old Rhine".

19th century

The mouths of the Linge in the Waal and in the Merwede were fitted with lock sluices in 1793 and 1810 respectively. In 1819, the Linge estuary was moved about 20 km down the merwede to Steenenhoek . In 1830 the "Kanaal door Voorne" was dug, the canal from the Brielschen Maas to the Haringvliet through the island of Voorne.

Until well into the 19th and 20th centuries, until the various major regulatory and land reclamation measures of the industrial age, the lower reaches of the great rivers could hardly be described as regular rivers. Due to the tidal current, they were usually so widened that they were difficult to distinguish from sea sections. The tidal flood worked far up the river, plus the damming triggered by the flood and the associated increase in the river water level. All of these effects were amplified by storm surges or river floods. In the Lek the tidal tide pushed forward to Schoonhoven , the damming went as far as Vianen . In the Waal the tide reached Gorinchem , the damming up to Zaltbommel . In the area of the Noord the tidal movement was even possible in both directions.

In order to facilitate the increasing shipping traffic, many rivers were regulated, especially around 1850. In the area of the fairway in the middle they were dredged and provided with groynes (Krib) on the banks. That meant a narrowing and deepening of the rivers. The rivers used by shipping traffic were dredged from 1900-1920.

The “Maasästuar” or “Lek-Waal-Ästuar” (Maasmond) around 1769, with the island of Rozenburg , the Scheur north of it, and the Hoek van Holland , through which the Nieuwe Waterweg will later be dug

today

In order to counteract further silting up of the Noord and the New Waterway as well as the flood risk emanating from the Waal, the approximately 20 km long New Merwede (Nieuwe Merwede) was dug from 1851 to 1860 (in the area of the Biesbosch tidal rivers created in 1421). This created a connection between Waal and Haringvliet, the Haringvliet became the main outlet of the Rhine system. The previous main outlet Brielsche Maas (Maas estuary) silted up. Since then, the Neue Merwede has led an average of 65% of the Waal water (corresponds to 44% of the Rhine water) to the sea.

The lower reaches of the New Maas, the former northern edge of the Maas estuary, is expanded to the Nieuwe Waterweg (New Waterway) in 1866–1872, mainly for the purposes of the emerging large-scale shipping industry. The name Scheur, the name of an original short northern branch of the New Maas around the island of Rozenburg, is retained. The New Waterway is 33 km long, 250 m wide and 10.5 to 12 m deep.

In 1872 the New Maas was enlarged to the New Waterway (Rotterdam Waterway) in order to create a better outlet for the Lek and to support the Rotterdam port facilities. Water is diverted there to ensure the port of Rotterdam remains operational. The deepening and widening at the Rotterdam port entrance led to the lowering of the river levels and the expansion of the tidal influence some 20 km further upstream. The tidal current extends 70 km upstream when the river is in high water and 90 km when the river is low.

Numerous shipping canals were built in the delta area for the industrial freight shipping that emerged in the 19th century. The most important canal structures include the "Kanaal van Steenenhoek" (near Gorkum, 1819), the Merwedekanal between Vianen and Gorkum (1881-1893), the Maas-Waal Canal (1927), the "Nieuwe Canaal van St. Andries" ( 1930) as well as the Amsterdam-Rhine Canal between the port of Amsterdam and the Waal near Tiel (1951).

20th century

For a long time the Maas flowed into the Waal at Heerewaarden. There, the Maas became part of the Rhine system and remained so when the Maas became partially independent again for a certain distance from Heerewaarden and flowed further down the Waal. In 1904 a channel called Bergsche Maas was dug from the Meuse to the Amer, a small tidal bay of the Biesbosch. The remaining course of the Meuse was dammed and has been called Afgedamte Maas ever since. Since then the Meuse has flowed into the Neue Merwede and the Hollands-Diep-Haringvliet bay. The excavation of the Bergschen Maas, the damming of the Afgedamte Maas and finally the construction of a dike at the site of the former (partial) confluence at Heerewaarden led to the complete separation of the Rhine and Maas.

The Zuiderzee bay was dammed with the so-called “final dike” in 1932, creating the sweet IJsselmeer. Between 1930 and 1968 four large areas with a total area of 165,000 hectares were polded and drained in it. The islands of Urk and Schokland became part of the Noordoostpolder . The planned drainage of the tidal areas was abandoned. The Markerwaardpolder planned for 1980 was no longer created, but the Markerwaarddijk remained.

The structures of the Delta Works

Area flooded by the Dutch storm flood in 1953

The large-scale Delta Works (also known as “Deltaplan” or “ Delta Project”) were implemented between 1950 and 1997. The idea for them was born before the Dutch storm flood in 1953 . The main aim was to provide better protection against storm surges . The implementation of the Delta Works began in 1950 with the damming of the Brielschen Maas. In 1958 the storm surge barrier was built on the Dutch IJssel. After that, between 1960 and 1987, four main sea-side main dams and five secondary dams further inland were built between 1960 and 1987 at great expense in the area of the south-western estuaries (1960 Zandkreekdam , 1961 Veerse Gatdam , 1965 Grevelendingam , 1970 Volkerakdam , 1971 Haringvlietdam , 1972 Brouwershavense-Gat dam , 1986 Oosterscheldedamm , 1986 Oesterdam , 1987 Philipsdam , 1987 Bathse Spuisluis ). Not all of the closed bays were transformed into freshwater lakes. For reasons of nature protection , the Grevelingen and the Oosterschelde were preserved as salt water basins. The Oosterschelde was even preserved from the influence of the tides. Westerschelde and Nieuwe Waterweg remained without a dike due to the heavy shipping traffic to Rotterdam and Antwerp . To compensate for this, the dikes along the Westerschelde were reinforced and in 1997 a storm surge barrier was installed over the Nieuwe Waterweg, the Maeslant storm surge barrier . At the same time as the Maeslant weir, the Hartel storm surge barrier was built between the port of Rotterdam ( Hartel Canal ) and Oude Maas .

Between 1961 and 1966, three large weirs were built in Lek and Nederijn, respectively. The Scheldt-Rhine Canal has connected the Volkerak with Antwerp since 1975 .

The delta works shortened the coastline between the western peaks of Walcheren and Voorne from 800 to 80 kilometers. Haringvliet, Hollands Diep, Volkerak and a small part in the east of the Oosterschelde became freshwater lakes. The runoff of the river water from the Rhine and Maas in this area takes place exclusively through the drainage sluices of the Haringvliet dam. The original plan was to lead all water from the Rhine and Maas into the sea through the New Waterway. However, since this did not appear to be feasible for floods and ice drifts, discharge sluices were built into the Haringvlietdamm. There are 17 huge gates with a maximum discharge of 21,000 m³ per second.

21st century

In the 19th and 20th centuries, dike breaches and floods were not uncommon. The large dike and shut-off projects have largely relieved the threat of floods from the rivers and the sea. Nevertheless, due to the tectonic subsidence (at Vlissingen 26 cm in 100 years), the location of many areas below the groundwater level and the expected rise in sea level, the control of the water in the Rhine delta and in the Netherlands will probably never be a closed case. The possible melting of all ice on earth (compare also ice age ) would lead to a rise of the sea level by 60 to 75 meters.

The increasing land consumption has dangerously decimated the remaining floodplains of the rivers, which is why excavated earth in the flood areas should increase their absorption capacity. "Side channels" should create more habitats for plants and animals.

Settlement, transport and economy

Closing dike on the IJsselmeer

People reached today's delta area at least 200,000 years ago. In the Neolithic Revolution (4450–1700 BC) forests were cleared and agriculture was carried out on the natural river dikes, the Aeolian dunes and the higher Pleistocene sands.

The first written records about the delta region come from the Roman period . They tell of Celtic and Germanic inhabitants, and also of Greek merchants looking for amber. Mela and Pliny tell of the Oenoern , which are supposed to feed on bird eggs and oats. However, the people presumably lived mainly from fishing and livestock. To protect against increased water levels, the residents built thousands of refuge mounds (called terpenes or sausages ).

Many villages were founded in Roman times. There was a dual economic system consisting of the indigenous subsistence economy with natural exchange and the Roman hierarchical market and money economy .

The most important Roman locations in the Rhine delta include:

Noviomagus , today's Nijmegen , on the upper Waal, capital of the Civitas Batavorum
Fletio, today's Vechten (municipality of Bunnik ), at the junction of the Vecht from the Oude Rijn, port and location of the fleet for Lower Germany. These functions were later transferred to the canal between the Oude Rijn and the Maas estuary, to Praetorium Agrippinae
Praetorium Aggripinae, near today's Voorburg , capital of the Civitas Cananefatium
Rossum

Even in antiquity, and possibly even before that, the Rhine delta was of paramount importance for shipping and the transport of goods. Nevertheless, the delta rivers had a dividing effect for the population groups. In any case, the delta retained its important function as a trade corridor between Britain and the Rhineland through all the political changes of antiquity until the 5th century.

Two early urban development phases can be distinguished in the delta area and its surroundings:

End of 7th - middle of 9th century: trading places ( emporia ): Quentovic , Domburg , Witla , Dorestad . For these places it was important that the Meuse formed the northern continuation of the Rhône-Saône axis, which was important until the 7th century. In addition, the North Sea trade was important, there were comparable emporia in the British Isles, in Scandinavia and in northern Central Europe (such as Haithabu and Birka ). In the 9th century, the emporia mostly went under, probably u. a. because of the loss of royal protective power.

Mid-9th - early 10th century: “Portus”: Maastricht , Liège , Huy , Namur and Dinant on the Maas, perhaps Antwerp , but certainly Gent , Tournai , Valenciennes on the Scheldt, Deventer on the IJssel, Tiel on the Waal. The portus are pre- and early forms of the “classical” medieval urban development of the 10th and 11th centuries. For the Portus, a castle or an abbey played an important role as a consumer center , stimulating trade. Through special legal statutes ( city law ), walling and development into long-distance trade centers , the Portus developed into full medieval cities.

Around 900 people settled in the east, especially in the area of the clay deposits on the bank walls and ridge. There were also numerous settlements at the estuaries and along the coast, some of which were in what is now the marine area. In the 10th century, the areas that had already been populated in ancient times were repopulated.

The moor areas in the west of the delta have been developed with dykes and polders since the 10th century . The moor areas were mainly in the county of Holland (the counts of Holland were therefore also called "water counts") and in the secular territory of the diocese of Utrecht (cf. today's Dutch provinces), the latter had developed around 950. Numerous place names on "-dam" were given in North Holland, as many watercourses there were dammed. The first mention of a dike in a place name can be found in 984 ( IJsendijk in Zealand).

Turning maneuver on the Scheldt in Antwerp

After the moorland was drained, the land surface sank by several meters due to the loss of water, the onset of oxidation and the mechanical stress, so that the polder areas are on average up to 2.5 meters below sea level, in places even more. At the same time, however, the bed of the rivers rose due to sedimentation, so that the construction of dykes along the rivers became more and more urgent; Dike breaches turned into major disasters. On the Lek, the particularly endangered areas began around Wijk bij Duurstede , on the Waal near Ochten .

Groundwater and rainwater must be drained regularly from the polder areas. For this purpose, the water was and is collected in small channels (“sloots”), which take up about 4–10% of the polder area and release the water into the rivers at low tide. In the case of lower-lying polders, the collected water first had to be moved into higher-lying basins or collecting channels, the so-called "Boezemwater" ("Boezemwater"). Since the 15th century, wind pumps that could raise the water by a maximum of 3.5 to 4 meters, most recently larger pumping stations that were first driven by steam engines and later by electric motors, provided this support work . A “Boezemgebied” comprises those polders that drain into a common Boezemwater. Water bodies in which the water could be shielded from excessively high water levels were used as Boezemwater: lakes (South Holland, Friesland), canals (including ring canals such as the "Ringvaarten") or streams converted into canals, which were dammed off from the sea or the main rivers for this purpose were. In the 13th century in particular, large ring dikes were created and, at the instigation of the Dutch Counts, water cooperatives were founded, which were responsible for drainage.

After the river basins were protected by dykes, the sediment load of the rivers was increasingly deposited in their beds, which increased them even further. This and the increase in rainfall since the 14th century made it increasingly difficult to maintain the dykes and resulted in devastating river floods. The rivers and polder dikes separated the individual parts of the country more and more.

When cultivating the bogs, mostly bog-hoofed villages were created. The corridors were divided into long, narrow parcels with drainage channels between them, which is why today the location of the former moorland can be easily seen on a map or from the air by the settlement structure. Around 1300 the cultivation measures in the moors were completed. Since the late Middle Ages, mainly cattle breeding has been practiced in these new land areas.

Important trading towns in the Middle Ages were Dorestad, Deventer, Stavoren on the east bank of the Flie, Medemblik on the west bank of the Flie, Tiel (briefly), Dordrecht and Vlaardingen. Geertruidenberg quickly lost its importance after the flood of 1421.

After the great flood of 1421, parts of the then lost land were drained again in centuries. The political and ecclesiastical borders continued to follow the disappearing rivers - the traditional naming regime was still of legal, political and economic importance. During the reclamation of new land, disagreements arose when old land rights were claimed or the course of earlier borders should be determined.

In the second half of the 19th and 20th centuries, the wind pumping stations in the polders were replaced by motorized pumping stations that were first powered by steam power, then by diesel and finally electrically. They helped keep the polders still sinking dry and also made it possible to dry out very low-lying areas between Rotterdam and Amsterdam; north of Rotterdam is the lowest land point in the delta at 6.7 meters below sea level. In the first state project in 1852, the Haarlemmermeer was polded in and drained with the help of steam engines.

Rotterdam with the older port facilities and surroundings

The Mannheim Act of 1868 allowed all neighboring states free navigation on the Rhine . Also due to the industrial development in the Ruhr area and the completion of the Nieuwe Waterweg, Rotterdam became the most important port in the delta area.

The industrial and port facilities of Rotterdam became some of the most important in the world. The Waalhaven was laid out in 1931. After 1945 the area of the so-called Maas estuary, i.e. the former estuary west of Rotterdam, was fundamentally redesigned. Port and industrial facilities were laid out over an area of over 25 kilometers between Rotterdam and the coast. At the traditional transshipment point in the port of Rotterdam, businesses that process goods, especially bulk goods such as crude oil and ores, have now sprung up. First the Botlek complex between Rotterdam and the former island of Rozenburg was completed in 1957, followed by the Eemhaven in 1967. The Europoort complex was built to the west of Rozenburg in the 1960s , bordered by the Brielse Meer (formerly Brielse Maas) and the Hartel Canal in the south, and by the Caland Canal and the New Waterway in the north . The westernmost port extension, the Maasvlakte ("Meuse area"), was raised in the 1970s and is largely already in the sea, i.e. west of the former estuary area. The small sea area of the Maasvlakte and the dam at Hoek van Holland is still called “Maasmond” today .

Antwerp , Amsterdam , Moerdijk , Nijmegen , Terneuzen and Vlissingen have other important ports .

At the Cape at Hoek van Holland, the kilometer 1032 also ends the Rhine, Waal, Merwede, Noord and Neuer Maas, which begins at the Constance bridge over the Seerhein . The strongest inland waterway traffic today takes place on the Rotterdam-Noord-Waal-Rhine and the Scheldt-Rhine Canal.

Meeswijk-Berg Maas ferry

In 1940 there were still 21 river ferries in the Netherlands. Today there are only a few river ferries left , mainly on the Rhine, Lek and Maas. The rivers are not only spanned with bridges for land transport, but also often tunnels under them. Well-known bridges are the Haringvlietbrug , the Moerdijkbrug over the Hollands Diep, the Prins-Willem-Alexanderbrug over the Waal and the Zeelandbrug over the Oosterschelde.

The delta area has been one of the most densely populated regions in the world for centuries. Important big cities include Antwerp , Amersfoort , Amsterdam , Apeldoorn , Arnhem , The Hague , Dordrecht , Haarlem , Haarlemmermeer , 's-Hertogenbosch , Leiden , Nijmegen , Rotterdam , Utrecht and Zwolle , well-known medium- sized cities are for example Alphen aan den Rijn , Deventer , Gorinchem , Kampen , Katwijk , Lelystad , Maassluis , Middelburg , Terneuzen , Tiel , Vlissingen and Zutphen .

Today's central locations in the delta area are Zwolle , Apeldoorn , Arnhem , Nijmegen , 's-Hertogenbosch , Middelburg , Rotterdam , Dordrecht , The Hague , Utrecht , Amsterdam , Haarlem , Alkmaar , Breda and Antwerp . With the exception of Antwerp, all these places are in the Netherlands.

Political history and borders

Germania inferior within the framework of the Roman provinces (the border line incorrectly along the Lek instead of the Oude Rijn )

During the Gallic War of Julius Caesar , the delta area fell around 55 BC. Under Roman rule. Since Drusus ' campaigns, the Romans established a permanent military presence. When the Romans arrived, different population groups lived in the delta area, especially the Batavians in the east, Cananefates in the west and Frisians in the north. The border between the Celtic population in south-central Europe and the Germanic population in northern Europe ran through the delta area. Especially in the first half of the first century AD, the imperial border between the Rhine and Elbe shuttled and was temporarily fixed along the Ems. Campaigns to the east were undertaken from the delta area. In AD 72, the Rhine-Nederrijn-Oude Rijn line became the imperial border, the right banks formed a border line. Numerous forts and legionary camps ( Lower Germanic Limes ) were built along the border, with civitates to the south . In 89 AD the province Germania Inferior (Lower Germany) was founded, the capital of which was Colonia Claudia Ara Agrippinensium (Cologne). According to Berendsen, the Oude Rijn was the same border river during the vast majority of the Roman Empire.

In 276 , Germanic tribes, known as Franks , destroyed the Lower Germanic Rhine Limes, the Romans from then on resorted to a system of deep defense. The northern border of the later province "Germania I" was a little more southerly than that of Lower Germany (possibly along the Lek or the Waal, possibly an indication of the shift in water volumes away from the Oude Rijn to Lek and from the Nederrijn-Lek to the Waal) along the Rhine and Waal to Heerewaarden and then followed the Maas and the eastern edge of the southwestern estuaries to the Scheldt estuary. However, the imperial border lost its protective function, which led to a sharp decline in population in the delta. Around 350 the invasion and settlement of Frankish, later called Salfranken (Salier) population groups took place instead of the Batavians in the eastern delta and south of the delta. The Salians became Roman allies and thus developed into a Germanic soldier class with the main task of defending the entire north-eastern border of the empire.

During the Roman rule, which lasted up to around 400, Germanic, Celtic and Roman settlers lived in the villages of the Delta. In the marshland areas mainly cattle breeding was practiced, in the Geest further inland, however, mainly arable farming . Between the Marsch or Cananefaten or Saliern in the west and the Geest or Batavern in the east, there were almost settlement-free bogs in many places. The imperial border along the Oude Rijn until 276 probably did not have much economic effect, because Cananefats lived north and south of it with the same material culture on both sides. Batavians and Frisians (both Teutons) were Roman allies at times.

Between 400 and 450 the Salians took over political power, then expanded south to the Somme and united the various Frankish kingdoms that had emerged at the end of the 5th century. The center of gravity of Frankish power was shifted from the delta area to the south ( Tournai on the Maas). In the delta area, a further sharp decline in population and the expansion of the forest could already be observed from 450 onwards. Only in the 7th century did the population in this northern border protection zone of the Salier Franconians increase again. The western delta was settled by Frisians from the north as early as the 6th century, perhaps also by Danes (Saxones Eucii) and Warnen (Varini). In the early 8th century, the Franks took control of the Frisians up to the Flie.

The delta area was directly affected by the Frankish divisions of the empire. When the empire was divided in 843 , the delta became part of the middle empire ( Lotharingia ). The Westerschelde and Schelde formed the border to the western empire , the IJssel partially that to the eastern empire . After the division of the empire in 870 , the border between East and West Franconia ran through the south-western delta region (Maas, eastern part of Haringsvliet, Oude Maas, Almere), in 879 this border was moved to the Scheldt and Westerschelde, where the border between West and Medium rich went.

The Rhine-Maas Delta at the time of the United Netherlands around 1658

In the 10th and 11th centuries the southern delta area belonged to the Duchy of Lower Lorraine , the northern to Friesland. In the southwest, the French county of Flanders extended into the delta area. In the 11th century, the County of Holland (originally "County of West Friesland") was separated from Friesland, which had extended to today's Belgian border for a long time. The Almere became the new western border of Friesland. In the course of time the following important political territories developed: Duchy of Brabant , County of Zealand , Diocese of Utrecht , Duchy of Geldern , County of Kleve . In the 16th century, almost the entire area came under the rule of the Spanish Habsburgs . To the north of today's Belgian-Dutch border, the independent United Netherlands soon separated , south of it the Spanish Netherlands , and from 1714 the Austrian Netherlands .

In the 17th century the " Dutch water line " was created. It was created by deliberately flooding the moorland by piercing dikes and was used to defend Innerholland in cases of war. It was further expanded and used for the last time in 1939/1940.

In 1795 the Austrian Netherlands fell to France, the United Netherlands was replaced by the Batavian Republic by the revolutionary government in Paris . In 1798, the remaining areas west of the Rhine fell to France. In 1806 the Kingdom of Holland was established instead of the Batavian Republic , but in 1810 the French Empire was expanded to include its territory and that of what is now northern Germany. In 1815 the United Kingdom of the Netherlands was created in the Congress of Vienna , which roughly comprised the present-day states of Belgium and the Netherlands. The border with Prussia was set up in the area of the former duchies of Kleve and Jülich, a cannon shot east of the Maas. 1831, the former northern border of the Spanish Netherlands became the southern Kingdom of Belgium established north the Kingdom of the Netherlands . Thus, the current state borders were essentially reached.

The position of the Dutch provincial borders compared to the rivers of the Delta

The present-day Netherlands are divided into several provinces , the borders of which are based on those of earlier territories. The provinces of Noord-Holland and Zuid-Holland correspond to the former county or the state of Holland, and the province of Utrecht corresponds to the former bishopric .

Large parts of the eastern delta area are in the Gelderland province ; the IJssel forms the border with the province of Overijssel for long stretches , the Meuse with the province of Noord-Brabant . The Waal does not form the provincial border anywhere in Gelderland. Central parts of the western delta area are in the province of Zuid-Holland ; the Grevelingen forms the border to the province of Zeeland , Hollands Diep and Neue Merwede that to North Brabant. The province of Utrecht lies in the middle of the delta, its southern border (to the provinces of Gelderland and South Holland) runs along the Nederrijn and Lek. For the northern delta area, the provinces of Noord-Holland between the North Sea and the IJsselmeer, Flevoland in the area of the new land areas of the Zuiderzee and Friesland northeast of the IJsselmeer should be mentioned. Of the 12 Dutch provinces, only three have no share in the Holocene delta landscape, namely Limburg, Drenthe and Groningen. While the share of North Rhine-Westphalia is negligible and is limited to small areas in the area of the division of the Rhine, Belgium's share is somewhat larger and extends from the province of West Flanders on the North Sea coast via the province of East Flanders to the province of Antwerp around the Scheldt estuary .

Cultural history

Some places and institutions have been named after the delta rivers. Some of the locations are far removed from today's waters and indicate that hydrographic and onomastic changes have occurred in the delta over centuries.

In the area of the division of the Rhine: Rijnwaarden .

In the Waal area: Valburg , West Maas en Waal , Nerijnen , Nieuwaal , Lingewaal .

In the area of the Old Meuse: Binnenmaas , Maasdam , Westmaas , Klaaswaal .

In the area of the Maasmond: Zwartewaal , Maassluis .

In the area of the Meuse: Maasland (municipality of Midden-Delfland ), Oude Maasdijk , Maasdriel , Waalwijk .

In the area of the Nederrijn: Rhenen , Rijn en Lek .

In the area of the Gelders IJssel: Rhienderen , Rheden .

In the area of the Lek: Rijnhuizen , Tull en't Waal , Nederlek , Lekkerkerk , Krimpen aan den Lek , Nieuw-Lekkerland , Lexmond (Leksmond).

In the area of the Crooked Rhine: Rijnestein , Rijnauwen , Rijnsweerd .

In the area of the Oude Rijn: Alphen aan den Rijn , Rijndijk , Katwijk aan den Rijn , Rijnsburg .

In the area of the Vecht: Nigtevecht .

In the area of the Dutch IJssel: IJsselstein , IJssellaan , Nieuwerkerk aan den IJssel , Ouderkerk aan den IJssel , Capelle aan den IJssel , Krimpen aan den IJssel .

The awareness that the Maas estuary or the Rotterdam region is the confluence of the Rhine was expressed in the name of the Rijnmond (“Rhine Estuary”) planning association founded on November 5, 1960 . Rijnmond is a public corporation consisting of 23 municipalities and covers 536 km² (of which Rotterdam: 186 km²).

Web links, literature, sources

Web links

Rhine-Meuse delta studies, Utrecht University English. Lots of insightful maps, texts and references.
The International Commission for the Hydrology of the Rhine Basin (CHR / KHR)
International Commission for the Protection of the Rhine (ICPR)
Rijkswaterstaat - Helpdesk Water (formerly: RIZA)

Standard works

Hendrik JA Berendsen: The Rhine-Meuse delta at a glance. Utrecht 2005 ( PDF version , under Geological evolution of the Rhine-Meuse delta ; accessed January 18, 2009)
Hendrik JA Berendsen, Esther Stouthamer: Palaeogeographic development of the Rhine-Meuse delta. Assen 2001 ( download of some attachments and appendices , under “Palaeogeographic evolution & avulsions”, accessed on January 18, 2009)
- Appendix 3, Channel belts in the Rhine-Meuse delta, u. a. with detailed information on the over 200 defined river beds, as of December 2005, PDF

Since 1990

Piet H. Nienhuis: Environmental History of the Rhine-Meuse Delta. Dordrecht 2008.

Theo E. Wong et al. a. (Ed.): Geology of the Netherlands. Amsterdam 2007.

Inventory of the Delta Rhine processing area (PDF) Dutch Ministry of Water Management, International Commission for the Protection of the Rhine - ICPR, 2005

Hendrik JA Berendsen: De vorming van het land, Inleiding in de geologie en de geomorfologie. ⁴ 2004 (physical geography of the Netherlands 1)

Wolfgang Schirmer, Wolfgang Boenigk: Landscape history in the European Rhineland. Munster 2004.

K.-E. Behre: A new sea level curve for the southern North Sea: transgressions and regressions in the last 10,000 years. In: Problems of coastal research in the southern North Sea area. 28 (2003), pp. 9-63.

Mark Cioc: The Rhine. An Eco-Biography 1815-2000. Seattle / London 2002.

H. Engel: Update of the monograph of the Rhine region for the period 1971–1990. 1997.

Henk JT Weerts: Complex confining layers. Architecture and hydraulic properties of Holocene and Late Weichselian deposits in the fluvial Rhine-Meuse delta. Utrecht 1996.

Henk Meijer: The Netherlands and the water. Utrecht u. The Hague 1996.

Hans M. Schmidt u. a. (Ed.): The Rhine - le Rhin - de Waal. A European stream in art and culture of the 20th century. Cologne 1995, catalog of the exhibition of the same name.

Henk Meijer: Small Geography of the Netherlands. Utrecht u. The Hague 1994.

Manfred Fenzl: The Rhine. Hamburg 1994.

Torbjörn E. Törnqvist: Fluvial sedimentary geology and chronology of the Holocene Rhine-Meuse Delta. Utrecht 1993.

Rudolf Straßer: The changes in the Rhine river. Düsseldorf 1992.

Oskar Bär: Geography of Europe. 1991.

K.-R. Nippes: Bibliography of the Rhine area. 1991.

1945-1989

Settlement research. Volume 7, Bonn 1989, several articles on the Rhine-Maas-Delta
Dieter Kelletat: Physical geography of the seas and the coasts. Stuttgart 1989.
Waldo H. Zagwijn: Nederland in het Holoceen. The Hague 1986.
Dieter Kelletat: Delta research. Distribution, morphology, formation and ecology of deltas. Darmstadt 1984.
Hendrik JA Berendsen: Geological changes in the western Netherlands during the period 1000-1300 AD Leidschendam u. a. 1984.
Hendrik JA Berendsen: De genese van het landschap in het zuiden van de provincie Utrecht. A physical-geographical study. Utrecht 1982 (including maps of the drastic changes in the course of the river around Utrecht between 3700 BCE and 1200 CE, pp. 146–147 and 187–192).
Orson van de Plassche: Sea-level change and water-level movements in the Netherlands during the Holocene. In: Mededelingen Rijks Geological Service. 36 (1), 1982, pp. 1-93.
Ingo Buhlmann: The Delta Plan. Paderborn 1981.
Orson Van De Plassche: Holocene water-level changes in the Rhine-Meuse-Delta… In: Geologie en Mijnbouw. Vol. 59, No. 4, 1980, pp. 343-351.
International Commission for the Hydrology of the Rhine Basin (CHR / KHR) _ The Rhine basin. Hydrological monograph. The Hague 1978.
Hermann Hambloch: The Benelux countries. Darmstadt 1977, pp. 16-21 and 49-55.
WH Zagwijn: The palaeogeographic evolution of the Netherlands during the Quaternary. In: Geologie en Mijnbouw. 5: 369-385 (1974).
Leendert P. Louwe Kooijmans: The Rhine / Meuse delta. Four studies on its prehistoric occupation and holocene geology. Leiden 1974.
Franz Xaver Michels: History of origin. In: Contributions to the Rhine customer. 1973, 25, pp. 3-24.
Maria K. Elisabeth Gottschalk: Stormvloeden en rivieroverstromingen in Nederland. 3 volumes (period up to 1700), Assen 1971–1977.
Jack Bax, J. Breadvelt: The mouth of the Rhine. In: World on the Upper Rhine. 10, 4 (1970), pp. 198-206.
C. Kruit: Is the Rhine Delta a delta? In: negot. Con. Nederl. Geol. Mijnb. Gene. Vol. 21, 1963, pp. 259-266.
Atlas van Nederland. 's-Gravenhage 1963 ff.
De Jong in: Geologie en Mijnbouw. Vol. 39 (1960), pp. 654-660.
JP Bakker in: Negotiations of the German Geographers' Day. 1957 (31)
Samojlov: the estuaries. Gotha 1956.

Before 1945

Lucien Febvre: The Rhine and its history. 1931 (translation 2006 et al.).
Historian Atlas van Nederland. 1 map series and several text volumes, 's-Gravenhage 1913 ff.
Arnold Norlind : The geographical development of the Rhine delta up to around 1500. Lund 1912 (reprint Osnabrück 1985, only of museum interest).
F. Andriessen: The relocation of the Meuse estuary. In: PM (Petermanns Mitteilungen) 1891, pp. 195–197, with map.
H. Blink: The Rhine in the Netherlands. Stuttgart 1889.

Others

Current and historical topographic maps of the Netherlands
Contributions to the Rhine customer. Messages from the Rhein-Museum e. V., Koblenz, Koblenz 1926 ff. (Magazine)

Remarks

↑ ^a ^b Berendsen / Stouthamer 2001, p. 13.

↑ Note: Dates that have already been calibrated are marked accordingly in the literature (e.g. "cal BP"). However, it was not always clear whether the BP information found was calibrated or uncalibrated, which is why the source should be consulted in an emergency. The deviations are particularly relevant for the Holocene.

^ For example, Buhlmann 1981, p. 7.

↑ Frank Ahnert, Introduction to Geomorphology , 4th ed. 2009, ISBN 978-3-8252-8103-8 , p. 204, para. 17.2.7, estuary delta : “An estuary delta combines the properties of a delta with those of an estuary , in which there are several mouth arms, which are widened funnel-shaped due to the action of the tides. ... the combined delta of the Rhine and Maas is of this type. "

^ For example, De Jong, 1960; Kruit, 1963 and Van De Plassche, 1980. Compare Berendsen / Stouthamer, 2001, p. 7.

↑ Berendsen 2005, p. 17 (Fig. 11).

↑ See Berendsen 2005, pp. 7–12.

↑ See Berendsen 2005, p. 15.

↑ Berendsen 2001, p. 7.

↑ Marcel de Wit, Robert Leander, Adri Buishand: Extreme discharges in the Meuse basin . (PDF; 2.16 MB), p. 2
Note: The value of 250 m³ / s most frequently found in the literature relates to the Borgharen gauge on the Belgian-Dutch border.

↑ Berendsen / Stouthamer 2001, p. 184.

↑ geo.uu.nl ( Memento of the original dated December 23, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed January 18, 2009. @1@ 2

↑ ^a ^b ^c Berendsen / Stouthamer 2001, p. 107.

↑ geo.uu.nl , accessed on January 18, 2009.

↑ One could also translate as “river belt” or “river course belt”, since Berendsen / Stouthamer also use “river channel”. See Berendsen / Stouthamer 2001, p. 184 and a.

↑ Berendsen / Stouthamer 2001, pp. 37–44, 49, 55–57, 184.

↑ Berendsen 2005, p. 6 (Fig. 2a) and 7, Berendsen / Stouthamer 2001, p. 8 u. 107.

↑ Berendsen 2005, p. 6 (Fig. 2b), 7, 8 (Fig. 3) and 9 (Fig. 4a).

↑ Ice Age: the development of this planet, mostly free of ice and frost, is frozen on its polar caps.

↑ ^a ^b Berendsen 2005, p. 8.

↑ Partly Berendsen / Stouthamer 2001, p. 107.

↑ Berendsen 2005, pp. 5-7.

↑ Berendsen 2005, p. 12.

^ Lexicon of Geography, Heidelberg a. a. 2002, Volume 3, pp. 91-94. See Berendsen 2005, p. 8.

↑ Berendsen / Stouthamer 2001, p. 8.

↑ Berendsen 2005, p. 6 (Fig. 2c), 7–8

↑ Berendsen 2005, p. 9 (Fig. 4), 11 (Fig. 6a).

↑ Berendsen 2005, pp. 6, 8.

↑ Berendsen 2005, p. 9 (Fig. 4).

↑ In part Berendsen / Stouthamer 2005, pp. 107-108.

↑ Berendsen 2005, pp. 10-11.

↑ Berendsen 2005, p. 8. The times are uncertain. See Lexikon der Geographie, Heidelberg a. a. 2002, Volume 3, pp. 91-94.

↑ Berendsen 2005, p. 10.

↑ Berendsen 2005, p. 10 (Fig. 5d), 11. Berendsen / Stouthamer 2001, p. 59ff.

↑ ^a ^b Berendsen 2005, pp. 11–12.

↑ Berendsen / Stouthamer 2001, pp. 63ff., 108, 251.

↑ See Lexikon der Geographie, Heidelberg a. a. 2002, Volume 3, pp. 91-94. As for the previous epochs, dates for the Holocene are problematic, as different classifications exist or the stratigraphic classifications are under discussion.

↑ Berendsen 2005, 14–15; Berendsen / Stouthamer 2001, p. 13 u. 101.

↑ Berendsen 2005, p. 5 (Fig. 1)

↑ Berendsen 2005, pp. 13-14; Berendsen / Stouthamer 2001, pp. 13, 77-92, 109.

↑ Berendsen 2005, p. 10 (Fig. 5d), 16-17.

↑ This paragraph and the entire chapter based on: Berendsen 2005, pp. 20–22; Berendsen / Stouthamer 2001, pp. 3, 76, 91, 97-105, 107 and 109.

↑ Possibly uncalibrated C-14 years BP (Before Present = 1950), which deviate more from the actual calendar years, the older they are. For the period dealt with in the table, however, it is hardly of importance (see chapter "Dating" ).

↑ Berendsen 2005, pp. 16-18.

↑ Berendsen / Stouthamer 2001, pp. 91–92, 109.

↑ Berendsen / Stouthamer 2001, p. 108.

↑ Berendsen 2005, p. 22.

↑ ^a ^b Berendsen / Stouthamer 2001, pp. 71–72, 108.

↑ Berendsen / Stouthamer 2001, pp. 72–73, 108.

↑ Berendsen / Stouthamer 2001, p. 15.

↑ ^a ^b ^c Berendsen / Stouthamer 2001, pp. 84–86.

↑ Berendsen / Stouthamer 2001, pp. 73–74, 108.

↑ Berendsen 2005, p. 23.

↑ ^a ^b Berendsen / Stouthamer 2001, p. 17.

↑ Berendsen / Stouthamer 2001, p. 16 (Fig. 2.10a), pp. 84–86. Berendsen 2005, pp. 24–25 (also: Fig. 19a).

↑ Berendsen / Stouthamer 2001, pp. 74, 108-109.

↑ Berendsen 2005, p. 24 (Fig. 19a); Berendsen / Stouthamer 2001, p. 16 (Fig.2.10a)

↑ ^a ^b Berendsen / Stouthamer 2001, pp. 74, 85.

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Berendsen 2005, p. 26.

↑ ^a ^b ^c ^d Berendsen / Stouthamer 2001, p. 75.

↑ ^a ^b Berendsen 2005, pp. 24-25.

↑ Berendsen / Stouthamer 2001, pp. 74–75.

↑ Berendsen 2005, p. 24 (Fig. 19b); Berendsen / Stouthamer 2001, p. 16 (Fig.2.10b)

↑ Berendsen / Stouthamer 2001, pp. 75, 91, 109.

↑ Berendsen / Stouthamer 2001, pp. 75–76, 109.

↑ Berendsen / Stouthamer 2001, pp. 85–86.

↑ See Berendsen 2005, p. 24 (Fig. 19c); Berendsen / Stouthamer 2001, p. 16 (Fig.2.10c)

↑ See Berendsen 2005, p. 24 (Fig. 19d); Berendsen / Stouthamer 2001, p. 16 (Fig.2.10d)

↑ Berendsen / Stouthamer 2001, pp. 75–76.

↑ Berendsen / Stouthamer 2001, pp. 18, 56, 76.

↑ Norlind 1912, pp. 149-153.

↑ See Berendsen 2005, p. 26.

↑ Berendsen / Stouthamer 2001, pp. 17–18, 56, 75–76, 91, 109.

↑ ^a ^b ^c Berendsen / Stouthamer 2001, pp. 76, 91.

↑ Norlind 1912, p. 200.

↑ See Berendsen 2005, p. 26; Berendsen / Stouthamer 2001, pp. 18, 76, 91.

↑ See Berendsen / Stouthamer 2001, p. 76.

↑ Berendsen / Stouthamer 2001, pp. 18, 92.

↑ ^a ^b Berendsen / Stouthamer 2001, p. 76.

↑ Berendsen / Stouthamer 2001, pp. 56, 76, 91.

↑ Berendsen 2005, p. 27.

↑ Norlind 1912, p. 40.

↑ Berendsen 2005, p. 26.

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t ^u ^v ^w ^x ^y ^z ^aa ^ab ^ac ^ad ^ae ^af ^ag ^ah ^ai ^aj ^ak ^al ^am ^an ^ao ^ap ^aq ^ar ^as ^at ^au ^av ^aw Receipt is still missing.

[BS01-13-1] Berendsen / Stouthamer 2001, p. 13.

[2] Note: Dates that have already been calibrated are marked accordingly in the literature (e.g. "cal BP"). However, it was not always clear whether the BP information found was calibrated or uncalibrated, which is why the source should be consulted in an emergency. The deviations are particularly relevant for the Holocene.

[3] For example, Buhlmann 1981, p. 7.

[4] Frank Ahnert, Introduction to Geomorphology , 4th ed. 2009, ISBN 978-3-8252-8103-8 , p. 204, para. 17.2.7, estuary delta : “An estuary delta combines the properties of a delta with those of an estuary , in which there are several mouth arms, which are widened funnel-shaped due to the action of the tides. ... the combined delta of the Rhine and Maas is of this type. "

[5] For example, De Jong, 1960; Kruit, 1963 and Van De Plassche, 1980. Compare Berendsen / Stouthamer, 2001, p. 7.

[6] Berendsen 2005, p. 17 (Fig. 11).

[7] See Berendsen 2005, pp. 7–12.

[8] See Berendsen 2005, p. 15.

[be7-9] Berendsen 2001, p. 7.

[WLBMQ-10] Marcel de Wit, Robert Leander, Adri Buishand: Extreme discharges in the Meuse basin . (PDF; 2.16 MB), p. 2
Note: The value of 250 m³ / s most frequently found in the literature relates to the Borgharen gauge on the Belgian-Dutch border.

[11] Berendsen / Stouthamer 2001, p. 184.

[f-12] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t ^u ^v ^w ^x ^y ^z ^aa ^ab ^ac ^ad ^ae ^af ^ag ^ah ^ai ^aj ^ak ^al ^am ^an ^ao ^ap ^aq ^ar ^as ^at ^au ^av ^aw Receipt is still missing.

Rhine-Maas Delta
The confluence of the Rhine and Maas from the west. Front: Rotterdam ports and Haringvliet ; Middle right: mouth of the Meuse
Data
location	Netherlands , Germany , Belgium
River system	Rhine and Scheldt
Important waters of the delta area	Rhine , Waal , Merwede , Nieuwe Merwede , Noord , Nieuwe Maas , Nederrijn , Lek , (Gelderse) IJssel , Maas , Schelde , Oude Rijn , Vecht , Hollandse IJssel , Linge (for more see the section on water list ) Coordinates: 51 ° 44 ′ N , 4 ° 43 ' O 51 ° 44' N , 4 ° 43 ' O51.730431 4.715881 51.730431 4.715881
Catchment area	240,140 km² (rounded); Rhine: 218,300 km², Scheldt: 21,863 km²
Outflow (rounded); Rhine: 2900 m³ / s, Scheldt: 127 m³ / s A _Eo : 240,140 km²	MQ Mq	3030 m³ / s 12.6 l / (s km²)