Schwielowsee
| Schwielowsee | |
|---|---|
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| Geographical location | Potsdam-Mittelmark district , Brandenburg ( Germany ) |
| Tributaries | Havel , Wentorfgraben, Mühlenfließ |
| Drain | Havel |
| Places on the shore | The city of Werder (Havel) with Petzow , Schwielowsee municipality with Caputh , Ferch and Geltow |
| Location close to the shore | Potsdam |
| Data | |
| Coordinates | 52 ° 20 '11 " N , 12 ° 57' 18" E |
| Altitude above sea level | 29.3 m |
| surface | 7.860 km² |
| length | 5,424 m |
| width | 2,025 m |
| volume | 22.17 million m³ |
| Maximum depth | 9.1 m |
| Middle deep | 2.8 m |
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particularities |
Glacier tongue lake and river lake of the Havel |
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The Schwielowsee is part of a chain of large lakes in the middle of the Havel river , which stretches from Nieder Neuendorfer See in Berlin to the Großer Zernsee behind Werder (Havel). It has an area of about 786 hectares. Its length is about 5.4 kilometers and its greatest width about 2.0 kilometers.
As a federal waterway, the Schwielowsee (SlS) belongs to the Potsdamer Havel , a branch line of the Lower Havel waterway , for which the Brandenburg Waterways and Shipping Office is responsible.
geography
The Schwielowsee is located in the Brandenburg district of Potsdam-Mittelmark and belongs to the municipality of Schwielowsee and the city of Werder (Havel). It extends in a northeast-southwest direction. The Havel flows through the lake in its northern area. The Havel reaches the southernmost point of its river here. Coming from the Templiner See through the Caputher Gemünde, it flows into the north-east into the Schwielowsee and leaves it at the northernmost tip through a bottleneck. This bottleneck is spanned by the Baumgarten Bridge, on which Bundesstraße 1 runs. After this narrow point, the Havel widens again like a lake, but without having its own lake name here.
From the Schwielowsee there is a connection in the northeast via the Wentorfgraben, which can be navigated by small boats, to the Petziensee, a bay of the Templiner See that is now separated by a railway embankment and has the status of another federal inland waterway. In the west, the Schwielowsee is connected to the Haussee in the Petzow Castle Park via a narrow ditch . The villages (districts) Caputh, Ferch , Petzow and Geltow lie on the banks of the Schwielowsee , with Geltow only touching the lake at certain points near Baumgartenbrück and Petzow being separated from the lake by the castle park and large silted areas.
geology
The Schwielowsee is a shallow glacier tongue lake . It was created around 19,600 to 19,000 years ago during the early Vistula high glacial and is embedded between the remains of various compression and set end moraines of the Brandenburg stage and the cold-time hall plateau of the "Glindower Platte", which was largely exposed by periglacial weathering . With the exception of areas of the Caputher locality, the north-west bank and the central and western parts of the Ferch locality, the Schwielowsee has more or less steep bank slopes, which are preceded by a wide silting terrace. The flatter bank areas, such as the area between Ferch and Petzow in front of the “Glindower Platte”, consist of chimney sediments and valley sands. The western part of Ferch is located in a meltwater channel made of sediments of younger age. The Mühlengrund in Ferch, located at the southernmost end of the lake, is to be understood as a meltwater breakthrough from the Ice Age glacier . This is where the glacier gate was located and the meltwater stream emerging from it washed away this depression. In the foreland of the moraine, the Zauche , he sedimented the rock material he carried with him to form a conical sand surface , the Beelitzer sand sand. Like the Schwielowsee, this glacier trough was considerably deeper in the early post-ice age than it is today. Back then, the Schwielowsee was located in a basin up to 40 meters deep, which today is mostly buried by remnants of dead plankton and washed-in sediments.
The water level of the Schwielowsee averages 29.3 m above sea level. NN . The highest elevation of the terminal moraine is in the vicinity of the district Ferch with the Wietkiekenberg 124.7 m above sea level. NN .
Hydromorphology
Water depths and stratification
The greatest depth of the Schwielowsee is 9.1 meters. It is in the extreme northeast. Overall, the northern lake area has irregular depths of 7 meters in places. The southern lake basin is evenly inclined to the northwest and does not get deeper than 4 meters. In contrast, the average depth of the Schwielowsee is comparatively small at 2.8 meters, because large areas in the middle of the lake and in the floodplain area of the Havel estuary are very shallow. In places the depth is only 0.5 to 0.8 m here. The Schwielowsee is therefore a body of water without appropriate stratification of the water masses in different temperature or convection levels . A complete water circulation , driven by the wind and favored by the Havel flow, exists all year round. Stagnation phases only occur when the ice cover is closed because of the density anomaly of the water .
circulation
According to the classification of lakes according to the number of full circulations per year, the Schwielowsee, like most shallow lakes in the temperate zone , is a polymictic body of water. Because of the non-stratified conditions, aerobic algae species dominate . Their supply of nutrient salts (e.g. phosphates ) and carbon dioxide is guaranteed all year round due to the lack of a barrier layer. Only with increasing darkening of the lower areas due to excessive algae growth is the phytoplankton living here no longer supplied with enough light and photosynthesis can only be carried out insufficiently or not at all. If the darkened phytoplankton ( detritus ) dies in large numbers, the predominantly aerobic conditions do not lead to excessive formation of digested sludge , methane gas and hydrogen sulfide at the bottom of the lake.
With prolonged exposure to the sun and high temperatures, the shallow Schwielowsee can be warmed up quickly and, due to its polymictic circulation, tends to multiply algae every summer, the so-called " water bloom ".
Chemical and trophic characteristics
Because of the decade-long entry of untreated wastewater as well as the entry of substances from intensive agriculture and the current release processes from the contaminated sediments of the Havel, there is still an oversupply of plant nutrients such as nitrogen and above all phosphorus , which increases the "water bloom" and increases the quality of the water impaired. According to a documentation drawn up by the Technical University of Cottbus , Chair of Water Protection , on behalf of the Federal Environment Agency , the visibility depth in the period from April to October 2001 was only 0.8 meters. The average pH value of 8.5 showed the Schwielowsee to be weakly alkaline . The measurements of trophy-relevant parameters during this period produced results that characterize the lake as "hypertrophic" (h1), the 8th level according to a new 10-point scale, or as "hypertrophic" (trophy level IV) of the conventional trophy system. According to the documentation mentioned above, the total phosphorus content in 1995 was still 180 micrograms / liter (= p2 - highly polytrophic) . In 2001, double the value was measured at 366 micrograms / liter (= h1 - hypertrophic) . This makes the Schwielowsee currently (2001) the largest lake in Brandenburg that is most heavily contaminated with phosphorus. The total biovolume of the lake in the months of July and August at 9.34 cm³ phytomass per m³ of water is relatively low in view of the high phosphorus values. The total nitrogen concentration declined in the assessment period 1995 to 2001, so that it is assumed that nitrogen could currently be the limiting factor for phytoplankton growth. The phytoplankton consists of 79 percent diatoms , especially the phosphorus- loving species Aulacoseira ganulata and A. ambigua , and 10 percent blue-green algae .
The water quality class of the Potsdam Havel is still III, heavily polluted. Since the Havel flows into the northeast of the Schwielowsee and leaves it again at the northernmost tip, the lake acts like a sedimentation basin for the suspended particles of the flowing Havel water.
The bottom of the lake
The lake bed in the area of the extensive shallows and near the shore consists of fine-grained, light gray sand, partly with silt, but mostly solid. Outside of the reed belt, the bottom of the lake is hardly overgrown with plants. In recent years, however, species of the genus of spawning herbs ( Potamogeton ) have spread to depths of around 0.5 meters . The deeper areas of the lake bed are formed by planktogenic sediments of diatomaceous flora mixed with microcrystalline lime.
The riparian zones
The river banks of the Schwielowsee are landing areas with wide and lush partly reed belts , lakeside often lined by cattail stands . The black alder forest is gradually expanding in the landside areas of the reed stocks . The vitality of the reed stocks has declined in recent years. A shoal with reed vegetation , which is a few hundred meters in front of the Flottstelle campsite , has almost completely disappeared in 2007. At the beginning of the 1990s, the diameter of this reed island was still over 40 meters. In other places, the reed spreads further on the lake side.
With an anthropogenically undisturbed course of development from its creation to the present, the Schwielowsee would today probably be a weak to moderately eutrophic , polimictic flat lake.
Schwielowsee and people
Due to the steep banks and the hilly relief that follows, the traffic routes are laid out on the silting terraces in the eastern and northern bank areas. Although the Schwielowsee is lined with forest in many places , the closeness to nature of the shore areas is disturbed by motor vehicle traffic . Only on the flatter west bank and in the area between Caputh and Flottstelle do the roads continue inland.
Large parts of the lake shore are built-up plots within the local area and are not publicly accessible.
Because of the wide siltation zones, there are hardly any “unofficial” bathing areas at Schwielowsee.
Since the Havel only flows through the northern end of the Schwielowsee, the heavy motorboat traffic is mainly limited to this area. Apart from this traffic on the Havel, the Schwielowsee is not very busy, even on summer weekends, and is mainly an area for sailing boats. An area for water skiing on the west bank of the lake can cause noise pollution for those looking for relaxation due to the strong boat engines used there.
The Schwielowsee is a popular fishing water .
water sports
In 2003 the first sailing club of the Schwielowsee, the Fercher Seglerverein 03 eV, was founded. Since then, regattas have been held annually on the lake by this association, mainly for the Ixylon and Contender boat classes . The highlight was the Einstein regatta of 15 and 20 dinghy cruisers on June 18 and 19, 2005, in which 93 boats took part.
On January 11th and 12th, 2003, the German Ice Sailing Championships took place on the Schwielowsee .
history
History of the shore region
The immediate vicinity of the Schwielowsee has been a settlement area of Germanic and later Slavic population since ancient times. However, there is no evidence of prehistoric settlements on the banks of the lake. In the vicinity of the lake, in the Lienewitzer Forest, a treasure find from the younger Bronze Age ( period Ha B1, approx. 1050–950 BC ), consisting of a cup-like gold vessel, two double spiral alarm rings and two gold spiral wires, documents trade relations with the southeastern European area of origin of the finds.
The village of Geltow , a bit off the northern shore of the Schwielowsee, was mentioned in a document as early as 993.
The village of Petzow is on the west bank . It was first mentioned in 1419. The Petzow Palace Park, a garden designed by Peter Joseph Lenné , is located directly on the Schwielowsee. Petzow Castle, a mix of Tudor and other neo-Gothic styles , belonged to the von Kähne family, who also owned the surrounding lands and operated several brickworks here.
The old fishing village Ferch , which today belongs to the municipality of Schwielowsee , is located on the south-west bank of the lake . Ferch, first mentioned in 1317, used to be divided into the Slavic lower and the German upper village, which indicates that it could have been a settlement in the early Middle Ages . Today Ferch is a popular place to live for people working in Berlin because of its convenient connection to the federal motorway 10 and has had a corresponding increase in population since the 1990s. The area around Ferch, almost without exception forest, is sprawled by dacha settlements .
Planned sea sludge extraction from the lake bed
Northeast of the Petzow district of Löcknitz, on the north-west bank of the lake, dredging work was carried out from 1987 to 1989 to create a branch canal and an inland port . It was planned to temporarily store sea sludge on the adjacent site , which was to be extracted from the bottom of the Schwielowsee. In the next 50 years, 33 million m³ of the lime-rich sea mud were to be stored and shipped here. The sea mud was to be used as a fertilizer . From around 1990 onwards, all work was discontinued for ecological and cultural-historical reasons. The claimed area was leveled.
Wildlife
fishes
Due to the abundant spawning zones , the Schwielowsee is very rich in fish. The main fish species are whitefish such as bream , roach and gustern , as well as carp and tench . Pike , pikeperch , perch and eels also live in the Schwielowsee.
Amphibians and reptiles
The pond frog , the main representative of the amphibian , is widespread in the reed belt of the Schwielowsee. Forest lizards live on the edge of the lake, directly in the transition to the humid zone of the silting belt . In sunny places, these reptiles are very faithful to their location. Grass snakes are water-loving snakes. They hunt frogs in the reed belt.
Birds
The coot (also called Lietze or Blässralle) is the most common water bird of the Schwielowsee. Mallards and mute swans are widespread . Tufted ducks , pochards , mandarin ducks and gray geese are rare breeding birds . Cormorants and gray herons are very common . Great crested grebes are rare, but they also breed at the Schwielowsee. The lush reed belts are the habitat of many reed warblers and similar songbird species. Accordingly, cuckoos also live near the shore of the lake. Rare breeding birds of the Schwielowsee are the pond reels, which can be observed from time to time as well as kingfishers in quiet reed bays. The red kite , buzzard and, more rarely, sea eagles circle over the lake regularly and in 2006 ospreys were observed. Laughing , silver and common gulls are among the most widespread gull species in the Schwielowsee.
The Schwielowsee is a migratory and resting area for waterfowl such as goosander , dwarf warbler , little grebe and golden-bellied ducks . Also Mittelmeermöwe and gull have been seen. In the late summer of each year, thousands of starlings gather in the reed belts.
Mammals
By far the most common mammals of the Schwielowsee are the muskrats . They live in the silting reed belt and mainly feed on aquatic plants. The silted up reeds, mixed with young black alder and willow trees , offer ideal day hiding places for wild boars . The pigs roam the bank zone on the beaten game paths.
Artistic reception
The painters Karl Hagemeister and Carl Schuch founded the Havelländische Malerkolonie Ferch in Ferch in the 19th century. Eugen Bracht and Hans-Otto Gehrcke painted on the banks of the Schwielowsee.
Theodor Fontane's messages about the Schwielowsee
In the summer of 1869 the poet Theodor Fontane visited Caputh. Together with three sons of the then Caputher ferryman, he undertook a leisurely sailing trip on the Schwielowsee. Fontane describes in his work Walks through the Mark Brandenburg the lake as comfortable and sunny and he has the good nature of all broad-based natures. Elsewhere it says:
“Schwielow is good-natured, so we said; but like all good-natured people, it can become violent, suddenly, almost unmotivated, and then it is unpredictable. Just laughing, a ripple and twist begins, now a vortex, a dusting up, a cloud - it is as if a hand is leading out of the funnel, and what is above it must go down ... There are whole lines where it failed ships. "
And further:
“We were now in the middle of the lake, the sun was behind a cloud, so that all glinting and dazzling stopped, and to the left the lake was now miles deep. A wreath of forest, surmounted here and there by individual poplars and brick food, bordered the wide banks; in front of us, under park trees, Petzow and Baumgartenbrück, to the left, at the southern tip of the lake, the lonely Ferch ... Now the width of the lake was behind us; through a belt of reeds and we glided up the muddy bank; only the stern of the boat was still in the water. Climbing up the hill, we looked for a shady spot under the roof of two half-grown acacia trees and now looked out at the bare surface, at the play of changing colors and the quiet life that glided over it. Blue stripes ran through the gray, then the other way around, and across these lines, over which the light glittered, the ships came and went. The sails stood dazzling white in the sun. "
Fontane raved about Baumgartenbrück and the location of his inn, saying it was a " Brühl terrace on the Schwielowsee".
Theodor Fontane takes the following view on the origin of the Schwielowsee in his hikes through the Mark Brandenburg :
“Perhaps this vast pool of water has not yet been counted for a thousand years, and it certainly doesn't go far back in prehistory. According to various indications, in the first centuries of our era the southern bulge of the Havel only extended about a mile beyond Potsdam, and an earth wall, the extent and nature of which it would be useless to conjecture , pushed between the higher at about the level of the village of Caputh situated Havel in the north and a deeper moorland in the south. Then, on a stormy night, a south-west dammed the Havel waters flowing towards it back as far as the Potsdamer Enge, and suddenly turning into an icy north-northeast, it pushed the towering mass of water against the earth wall with such force that it broke and the Havel waters, which had been dammed up until then, were like poured from a lock into the deeper moor basin. Schwielow was born that night. "
According to this theory, Fontane leaves open exactly where the Havel should have flowed beforehand.
See also
literature
- Johannes H. Schroeder (Ed.): Guide to the geology of Berlin and Brandenburg. No. 4: Potsdam and the surrounding area. 2nd Edition. Self-published Geoscientist, Berlin 2001, ISBN 3-928651-09-9 .
Web links
- The Schwielowsee. Profile at the Brandenburg State Office for the Environment
- Paleolimnian model construction and biocene-based assessment approaches for river lakes using the example of diatoms (= specialist articles by the State Environment Agency . Issue No. 93, 2005. PDF file, 2 MB).
- Documentation of the condition and development of the most important lakes in Germany. Part 5: Brandenburg. Environmental research plan of the Federal Ministry for the Environment, Nuclear Safety and Nature Conservation (PDF file, 2 MB).
swell
- ↑ Directory E, serial no. 60. In: Chronicle of the legal status of the Reich waterways / inland waterways of the federal government, water and shipping administration of the federal government.
- ^ Directory F: Other Federal Inland Waterways. In: Chronicle of the legal status of the Reich waterways / inland waterways of the federal government, water and shipping administration of the federal government.
- ↑ Rituals in prehistory, antiquity and the present. Studies in Near Eastern, Prehistoric and Classical Archeology, Egyptology, Ancient History, Theology and Religious Studies. Conference publication of the interdisciplinary conference from 1. – 2. February 2002 at the Free University of Berlin. Rahden (Westf.), Leidorf 2003 (= international archeology. Working group, symposium, conference, congress. Vol. 4).
- ↑ quoted from: Theodor Fontane: Wanderings through the Mark Brandenburg. Paperback edition in 5 volumes, Vol. 3: Havelland. Nymphenburger Verlagshandlung, Munich 1971.