Würzburg gauge
The Würzburg gauge is one of 16 measuring gauges and eight guide gauges on the Main and measures the current water level, which is of great importance for shipping and residents. In the case of flooding , it serves as an important point of reference for regions located downstream from the banks in order to issue appropriate warnings.
The Würzburg gauge is roughly halfway between the source and the mouth of the 524-kilometer-long Main on the Alter Kranen near Würzburg . It has been observed regularly since October 1823 and is the oldest operating gauge on the Main. The operator is the Wasserstraßen- und Schifffahrtsamt Schweinfurt (WSA Schweinfurt), which also evaluates the data. The highest registered water level comes from March 30, 1845 with 834 centimeters, the lowest comes from 1934 with 116 centimeters with a mean water level of 176 centimeters.
description
The Würzburg gauge consists of three level gauges , with the first level located directly at the Alter Kranen . The second season, the flood season, is located at the crane bastion , which is directly adjacent to the old cranes . A third series of floods has existed at the Old Main Bridge since 1823 . The level also includes a write level and a measured value announcement device. The recordings began in 1823, making it the oldest operating gauge on the Main. In the course of the congestion regulation , the even older Lohr gauge at Main km 197.97 was abandoned in the 1930s .
The reliable recording and evaluation of water levels form the basis for all hydrological work on the river. This includes conscientious discharge measurements with different water flow. Due to the relationship between water level and runoff, the water levels can be calculated according to the runoff quantities and shown in the runoff curve . Exact knowledge of the runoff is the prerequisite for the operation, maintenance and expansion and new construction of the waterway , for the control of the individual systems on the river, in particular the barrages with weir and hydroelectric power station , for shipping to determine the fairway conditions and the disposition the dumping depth as well as for the flood intelligence service for shipping and residents who live in threatened areas.
The measured values are transmitted to the writing level at the Wasser- und Schifffahrtsdirektion Süd (WSD Süd) and to the Federal Institute for Hydrology (BfG) in Koblenz and made available via an automatic answering machine that converts the measured values into speech, via the Main skipper or interested parties be able to provide information on water levels and trends. The level is managed in the network of nationwide measuring points with the number 24042000.
location
The level is at Main-kilometer 251.97, the catchment area above the level is 13,995.76 km². The level zero point is 164.553 meters above sea level . The water level of the river downstream barrage Erlabrunn is 165.78 meters above sea level high, which corresponds to a water level of 123 centimeters.
The Würzburg gauge is an important reference level for shipping and includes the river section from the Harrbach lock to the Marktbreit lock , Main kilometers 219.47 to 275.68. This section is used annually by around 9,000 cargo ships carrying nine million tons of cargo. The gauge will be replaced downstream by the Steinbach gauge at Main kilometer 200.52 and upstream by the Schweinfurt - Neuer Hafen gauge , Main kilometer 330.78. The next upstream is the Astheim gauge at Main kilometer 311.20.
Main values
| Water levels (annual series 1994-2003) | ||||
|---|---|---|---|---|
| Main values of the annual series | winter | summer | year | |
| NW | lowest daily mean | 135 cm | 137 cm | 135 cm |
| MNW | mean annual low water | 145 cm | 141 cm | 141 cm |
| MW | mean water level | 197 cm | 155 cm | 176 cm |
| MHW | mean annual high water | 480 cm | 246 cm | 503 cm |
| HW | highest water level | 648 cm | 482 cm | 648 cm |
| Discharge (annual series 1989-2003) | ||||
|---|---|---|---|---|
| Main values of the annual series | winter | summer | year | |
| NQ | lowest daily mean | 26.3 m³ / s | 29.0 m³ / s | 26.3 m³ / s |
| MNQ | mean annual low water | 67.3 m³ / s | 56.9 m³ / s | 56.2 m³ / s |
| MQ | Medium drain | 160 m³ / s | 84.6 m³ / s | 122 m³ / s |
| MHQ | mean annual high water | 664 m³ / s | 242 m³ / s | 696 m³ / s |
| HQ | highest discharge | 1390 m³ / s | 786 m³ / s | 1390 m³ / s |
The measured values at the Würzburg gauge are summarized in the hydrological year , which lasts from November 1st of the previous year to October 31st. The months of November to April comprise the winter half-year and the months May to October the summer half-year. In contrast to the calendar, this classification was chosen in order to be able to record the precipitation in the annual balance , which was already stored as snow or ice in November or December and can only flow away in warmer weather in the following year. The water levels and runoff from several years are summarized in order to compare them with other levels and to use them for the shipping route, the operators and residents. Due to the amalgamation of several values, extreme values are not so noticeable and the mean values are more balanced.
Between 1994 and 2003, the Main had an average water level of 176 centimeters at the Würzburg gauge . The water level fluctuates over the course of the year and averages 197 centimeters in winter and 155 centimeters in summer. The highest water level at the Würzburg gauge was measured on March 30, 1845 with a level of 834 centimeters and a discharge of 2170 m³ / s. An even more extreme flood, of which there is a marking in Würzburg, occurred on February 29, 1784 with a height of 863 centimeters with a discharge of 2600 m³ / s. The Main had its lowest water level in 1934 at 116 centimeters. The absolute lowest water level, caused by a damming of the Erlabrunn barrage, was 87 centimeters on September 3, 1953. The lowest discharge was in 1964, when only 12.2 m³ / s flowed. The average annual runoff for the period from 1989 to 2003 was 122, 160 in winter and 84.6 m³ / s in summer. The average water level in the period from 1824 to 1998 was 223 centimeters with a discharge of 107 m³ / s.
Level changes
| Level changes | |||
|---|---|---|---|
| Period | Height above sea level |
||
| from | to | ||
| October 1, 1823 | September 10, 1842 | 166.766 m | |
| September 11, 1842 | June 30, 1887 | 166.693 m | |
| July 1, 1887 | July 31, 1955 | 165.556 m | |
| August 1, 1955 | today | 164.553 m | |
The level zero point had to be lowered several times since 1823 so that it was always below the lowest water level. This was necessary because the water level sank due to the natural deepening of the river bed and the various expansion measures for better navigability. The level was lowered three times by a total of 221.3 centimeters. Without this lowering, the gauge would no longer reach into the water at mean water today. The water level lines were measured from October 1, 1823 to March 31, 1872 using the units of measurement used at the time, feet , inches and lines . To evaluate the old level measurements, they were converted to the metric system and to the level values that are valid today.
Discharge measurements
The oldest known discharge measurements on the Main date from 1849 in the Wertheim and Aschaffenburg area . However, these measurements cannot be used for investigations in Würzburg, because the Main covers a much larger catchment area there. In the closer area, the first measurements took place on October 3, 1850 in Schonungen . In Staffelbach , Laudenbach , Wernfeld , Obertheres and Gemünden am Main , measurements were made in 1867 and 1868 with a Woltmann grand piano , a tour counter that was held in the water for three minutes. The discharge was determined based on the flow speed of the water and the flow cross-section of the measuring point.
These old measurements are particularly valuable for Würzburg because they show the original state of the Main in Würzburg before it was softened. Below Viereth , when the Staffelstein breakthrough, the next measurements followed in 1877.
In the years 1880 to 1886, nine measurements were carried out in Würzburg for the first time, one of them during the flood in 1880 with a discharge of 939 m³ / s. These measurements, however, proved difficult. Written permits from the city and the Bavarian military administration had to be obtained to tension the rope for the Woltmann wing from one bank to the other. The town owned the wall at the town's wooden yard on the right bank of the river and the military owned the fortress wall on the left bank.
In the years 1884 to 1886, a total of eight discharge measurements were carried out in Schweinfurt , which were carried out with considerable precision and great care.
In Würzburg, 18 discharge measurements are available for the period from 1900 to 1934, including a series of eight discharge measurements from the flood at the beginning of November 1924. From the time after the completion of the barrage in Erlabrunn , the subsequent damming of the Würzburg level and the partial dredging of the shipping channel in 1938 and 1939 there are three measurements.
From the intermediate state of the Main between 1939 and 1952, 21 measurements are available. After the construction work, which was completed in Würzburg in 1954 and which led to major changes in the water level, a total of 57 discharge measurements were carried out by the end of 1974.
Drainage board
| Discharge table - values in m³ / s | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| cm | 00 | 10 | 20th | 30th | 40 | 50 | 60 | 70 | 80 | 90 |
| 100 | 165 | 187 | ||||||||
| 200 | 207 | 227 | 245 | 264 | 280 | 297 | 315 | 333 | 350 | 369 |
| 300 | 387 | 407 | 426 | 445 | 465 | 485 | 505 | 525 | 545 | 570 |
| 400 | 590 | 610 | 631 | 655 | 675 | 700 | 730 | 755 | 780 | 810 |
| 500 | 840 | 870 | 900 | 930 | 960 | 995 | 1030 | 1060 | 1100 | 1150 |
| 600 | 1190 | 1230 | 1270 | 1310 | 1360 | 1400 | 1450 | 1500 | 1550 | 1600 |
| 700 | 1650 | 1710 | 1760 | 1810 | 1860 | 1910 | 1960 | 2020 | 2070 | 2130 |
The known discharge measurements and the associated water levels at the gauge were drawn in a discharge curve. The areas in the low and high water areas for which no discharge values are available were determined by extrapolation . With this discharge curve, each measuring point stands on the line for the discharge at the corresponding water level.
In addition, the values of the discharge curve are shown in the discharge table. In this case, the water levels are given in steps of one hundred on the left and the intermediate values in steps of ten centimeters above. In this way, the associated discharge rates for the water levels can be read off in ten-centimeter steps. For example, a water level of 440 centimeters corresponds to a discharge of 675 m³ / s.
Slopes
The Main has a natural gradient from Kulmbach , the junction of the White and Red Main , of less than one per thousand . Below Kulmbach the gradient is on average 1.08 per thousand, in the Würzburg area less than 0.5 per thousand and in the lower reaches near Frankfurt am Main only 0.29 per thousand. The flow gradient was reduced by the barrages. There are 34 theoretically horizontal dams on the Main. However, due to the constantly flowing water, these are actually not horizontal. The destination of the Erlabrunn lock is 165.78 meters above sea level. At the Würzburg gauge , this corresponds to a water level of 123 centimeters. The actual mean water level at the gauge is 176 centimeters. The Erlabrunn dam, at the upper end of which is the Würzburg gauge , has a gradient of 53 centimeters over a length of eleven kilometers.
In relation to the conditions of the Main river stretch of the building authority district Würzburg from the year 1864 the oldest information about the water level gradient is contained. There it is said that the Main below the Old Main Bridge is almost horizontal for a length of 2000 feet (584 meters). The gradient was from the Pleichach estuary on a length of 21,000 feet (6129 meters) 10.9 feet (3.18 meters). This corresponds to 0.52 per thousand.
Water level fixations
The earliest water level fixation at low tide dates from 1869. The gradient from the Pleichach estuary to the Old Main Bridge is given as very small, at a maximum of two to three centimeters. During the course of various flood waves in 1882, several crown fixings were carried out for the first time on both banks. This showed the unfavorable influence of the Old Port, which was built a few years earlier . The measurement showed an increased water level gradient compared to the previous state.
For the passage of the flood waves in 1909, 1947 and 1970 there are further water level fixations. These are also present in the case of lower water flows. They come from both before and after the expansion of the Main to become a major shipping route.
history
In Bavaria, regular water level observations have been carried out since the beginning of the 19th century. On May 19, 1821, the then Ministry of Finance issued a general order to set up a gauge network on all navigable and raftable rivers. This first measuring network comprised 65 measuring gauges until 1826, with the water level being read at the stations once a day. Occasional interim observations were made during floods. The Bavarian network has grown to over 700 measuring points to date, of which more than 300 are integrated into the flood intelligence service.
It is not known exactly when the Würzburg gauge was built. The first recordings date from October 1823. In 1823 the Würzburg gauge consisted of two vertical level slats, until 1872 with the then common foot and customs division. The first season was in a niche on the stairs on the right bank of the Main, 70 meters below the old crane . The second relay, which was also the flood relay, was 400 meters upstream, on the downstream side of the left abutment of the Old Main Bridge . The two level bars were attached in such a way that at the time of the flooding of the first relay, the same values were also obtained on the flood relay.
The staff level was usually only read once a day, usually between six and eight in the morning. At times two daily readings are also noted on the water level lines. In the case of floods, people were generally content with the indication of the maximum level and the approximate time of the peak wave. That is why some values before 1887 were a little too low. Hourly observations or interim readings appear much later.
The first season was relocated on July 21, 1961 directly at the old crane . In addition, a new flood relay was attached to the crane bastion . For the first time, all gauges were in the same profile and on the same bank of the Main. In order to serve as an important link to the level information before 1961 and the height information of the great historical floods, the old flood relay was also left at the Old Main Bridge . This level staff has been in the same place since 1823. Comparative measurements during the flood in February 1970 showed the same values on this gauge as on the new flood relay at the crane bastion , although extensive changes had taken place in and on the river in the meantime.
On the right bank of the Main, the first writing level in Bavaria was erected in a wooden house on the Kranenkaimauer on November 1st, 1883 to prevent flooding. Access was via a catwalk from the municipal timber yard . However, the automatic level often had problems in the early days. The usable diagrams that are still available today date from 1887. For urban planning reasons, this gauge house had to be removed in 1913. The writing level was then relocated to the crane bastion , a level shaft with an inlet to the Main was built in the front corner of the Alter Kranen bastion and protected with an attached tin house. On April 24, 1914, a remote electrical level was put into operation at the write level. The measured data went from there to the road and river construction authority at the time and to the gauge at the municipal warehouse at the old port .
During the bombing raid on Würzburg on March 16, 1945 , the remote level was completely destroyed and the writing level was stolen in the turbulent days after the air raids. After the devastating air raid, most of the residents fled the city and the water level was no longer read. In Würzburg, on April 2, 1945, on the eve of the American invasion, retreating German troops blew up all the bridges over the Main. Among them was the Luitpold Bridge (today's Friedensbrücke ) below the level. The debris of the bridge that fell into the river created a meter-high damming.
Regular level readings began again on May 14, 1945. The water levels were still influenced by the backwater of the river. In July 1945 the clearing of the bridge debris began. This work lasted until October 15, 1945. From then on, the water level conditions were normal again in the area of the water level. The observation gaps that arose as a result of the war events could be closed by observations at the Ochsenfurt gauge .
A remote electrical level was put back into operation in January 1948. The data was transferred to the Würzburg Waterways and Shipping Office (WSA Würzburg) at Friedrichstraße 2. The electrical remote level has been located in the foyer of the Wasserschifffahrtsdirektion Süd (WSD Süd) in Wörthstraße 19 since spring 1987. The tinny gauge house was dismantled in 1970 and replaced by a massive gauge house. The gauge system has been equipped with a measured value announcement device since June 25, 1970. A data storage and remote data transmission device Allgomatic-Outdoor station-DFÜ-T went into operation on September 23, 1985.
On the occasion of the reconstruction of the customs house on the crane bastion and the rededication as the House of Franconian Wine as well as the flood protection in the area of the crane bastion that was carried out at the same time, the level system was relocated to the new measuring room of the newly designed Biedermeier house on June 28, 1990 . The level shaft was retained. During the construction period from October 1988 to June 1990, the level system was housed in an auxiliary level house.
Construction work in the area of the gauge
Since measurements began at the Würzburg gauge in 1823, many structural changes have been made to the bordering bank of the Main, but also to the river bed . The river bed, which was originally irregular, was designed as a profile over time, which had an impact on the flow velocity. After the fortress status of the city had been lifted - on the right Main Main the royal approval was given on September 28, 1856, on the left Main Main district on May 7, 1867 - it was partially deconsolidated. The softening in the Main area dragged on until 1898 and was completed with the construction of the left Main quay wall. The Main was expanded in several stages for the ever larger ships.
The construction work included dredging in the river bed in order to achieve greater fairway depths for shipping. As a result, the main mirror sank considerably. In addition, there were constant changes in the bank development, which influence the profile of the river and valley. The width of the river was reduced. The bank development also resulted in a straight bank course. The river dredging reduced the roughness of the river bed, which increased the flow velocity of the Main. As a result, much more water can be carried through today in the same period of time than in the past, which means that a flood wave now flows away faster than before. These construction measures had different effects on the level measurements.
River topography around 1823
At the beginning of the level measurement in Würzburg, the city was still surrounded by a mighty baroque fortification belt from the second half of the 17th century, on the right side of the Main the city fortifications and on the left Main district the Mainviertel , which was attached to the fortress Marienberg . The so-called water glacis , which were also part of the fortifications , stretched along both banks of the Main . For military reasons, the fortifications were subject to strict building regulations, which were considerably tightened, especially for the glacis. As a result, the river bank in Würzburg remained untouched for a long time. The only river crossing in the wide area was the Old Main Bridge . All other bridges in the city area were built much later.
The river in the city area was much wider, the river bed was higher. A layer of sand and gravel up to one meter thick lay over the bottom of the wave limestone . In the river bed there was a channel on both banks, depending on the current. On the right bank of the Main, this channel was created by the operation of the Lower Main Mill and as a result of the water flowing through the needle weir and was used by shipping as a route. By operating the other two mills, the Upper Main mill and channel mill and the overflow water of the match weir also a channel formed on the left bank.
Right bank of the Main
The right bank of the Main below the Old Main Bridge was then, as it is today, bordered with a vertical quay wall. At the wooden gate , only the lower bank of the Main was raised a little in recent times, but this had no effect on the water level. As the name of the gate suggests, mainly wood and fuel were unloaded in this area. The entire shoreline was used by freight ships waiting to be processed at the old crane . A little below the old crane stood an iron crane erected by the Würzburg trade association to support it . On the same side of the bank there was also the pull path for the towing ship , but this was obstructed by the loading operations at the quay wall. Small market ships that supplied the city's green market with fresh goods were also located on this quay.
The terrain sloped down after the Kranenkai and was deeper than it is today. The Kürnach , a stream that comes from the village of the same name 14 kilometers northeast of Würzburg, flowed freely at the current row of houses on the Kranenkai and served to irrigate the medieval city fortifications from the 14th to 16th centuries, the so-called Inner Trench . Allotments were behind it. Later the area was filled up to today's level. Since the area is completely shaded by the flow of the crane bastion , this filling did not affect the flood discharge.
At that time there was an unpaved earth embankment below the quay wall. This was caused by irregular backfilling of the foreland that used to be much lower down. Slightly above the corner bastion of the city fortifications, the freestyle diversion running parallel to the Main, which had previously taken up the Pleichacher Mühlgraben , ended. The rather wide moat, filled with water, ended here. This ran to the Pleichacher gate bridge . It served as a wintering place for the ships and was closed to the river with a stone dam except for a narrow opening. This moat was filled in during the demolition in 1877 and the city slaughterhouse was built on this site.
Left bank of the Main
The right bank was mainly used for shipping, the left bank was mainly used by traders. The fishermen set up their nets here and camped their boats . The shipbuilders used it as a shipyard. Between the fortress wall and the river, the bank was then only about half as wide as it is today and was also much deeper. It was often flooded and was only about one meter above low water. Its embankment fell steeply to the Main. It was not a natural bank. It was probably filled with excavated material from the construction of the fortress wall in the second half of the 17th century.
At that time, the water level reached up to the middle of the land opening at the Old Main Bridge . The bank stretched in an irregular course up to the star bastion. The shore area was only accessible through the Dreikronentor and the fishing gate. In 1890 the three-crown gate was demolished after there was no longer sufficient headroom due to the considerable elevation of the bank. The flood relay at the Alte Mainbrücke is a little above it.
The bank below the star bastion became much narrower. The unpaved foreland had obviously been washed away by the numerous floods. This narrow, used bank strip was accessed through a small gate. At that time, the fortress wall and the thick tower were still completely in the water a little further below . In the current shadow of the thick tower , which protruded into the river, there was a narrow strip of shore. Allegedly this round artillery tower disrupted the flood discharge, which is why it was demolished in 1889. In 1954, when the left bank of the Main was redesigned, the foundations were exposed and the tower was rebuilt halfway up.
The corner bastion, today's Jahnterrasse on the Viehmarktplatz, was also washed around with water . This water surface extended into the moat. A retaining wall several meters high was built on the lining wall of the moat opposite the corner bastion to protect against flooding . However, this had a rather unfavorable influence on the flood discharge. During the German War of 1866, the crown of the wall was fitted with wooden palisades on the sloping glacis slope towards the Main.
Main correction from 1823 to 1913
The inadequate depth of the fairway and the poor condition of the Main for shipping caused many of those affected to apply to the government of the Lower Main District for remedial action and improvement at the beginning of the 19th century . In the 1820s, the aim was to remove the numerous river bends with punctures and thus to shorten individual river sections. The Korrektionsarbeiten experienced in 1830 a lively recovery. This came about through the Ludwig-Danube-Main Canal, which was under construction at the same time . With the introduction of steam shipping in 1841, there was a further increase in shipping traffic.
In order to achieve greater waterway depth for shipping, attempts were initially made to limit the width of the river by means of groynes at particularly critical points . In the later expansion, these groynes were provided with so-called wing groynes due to the experience gained in the meantime. In order to reduce the heavy deposits, the fairway was further improved by means of continuous tail units from the 1850s. Some of these groynes are still visible today.
The crown of the groynes was originally placed 40 centimeters above low water. However, this was later increased to 75 to 100 centimeters. Due to frequent flooding, the pull path for towing boats also had to be increased. This work dragged on for almost a century and was completed with the low water regulation on the Schwarzenau – Schweinfurt route.
The gauge network on the Main was further expanded during the regulation work. So-called construction and low water levels were set up next to the main ones. As a rule, observations at these gauges only began after the construction work had moved in the immediate vicinity of the gauges. The regulation work at the gauges led to major changes in the water level.
Due to the increased clearing power of the water in and above the punctures, the sole deepened considerably. The water level of the Main sank accordingly. This persistent deepening often lasted for a long time and only came to a standstill, as in Viereth near Bamberg, with the construction of the barrage. In the areas without punctures, the regulation sections, the main mirror was raised by the installation of the tail units and groynes. Due to the deepening of the riverbed caused by the narrowing of the river, the water level sank again in the low water area. At higher water levels, the damming prevailed again. In most of the river, there was no stable situation during this period due to the repeated changes in the altitude of the regulatory works, the continuous deepening of the riverbed and the dredging in the silting sections.
The inner city area of Würzburg was left out of the mean water regulation. One reason for this was the fact that the river banks were part of the military exclusion zone until the fortress status was abolished. In 1872 there was a project to remove the weir in Würzburg and to narrow the Main with tail units. This failed not least because of the high costs.
Steamship port construction 1845/1846
A group of enterprising merchants founded a steamship company in 1841 due to the economic boom and the increase in traffic on the waterways. In 1842 the company initially put two ships into operation. A sheltered berth was needed for the two large ships. The part of the moat used for wintering ships was too small and too heavily occupied. A separate port was therefore built on the upstream bank between the cutting tower and the corner bastion. The freestyle derivation flowed into the Main there. Construction work began after the great flood in March 1845. Another flood in June 1845 initially interrupted construction work. In 1846, after some difficulties, the port could be put into operation.
The port was about 100 meters below the level. It was bounded on the land side by the city wall and on the river side by a paved dam on which a berm for towing ships extended. The harbor basin was closed off from the upstream by a wall running diagonally to the river. The embankment pushed the bank a few meters into the river. A paved embankment made the connection to the crane quay wall.
The subsequent derivation of the freestyle had to be relocated in the lower part due to the construction of the port. It was led into the Main in a fixed channel along the harbor wall. A small pull-way bridge served as a crossing for towing.
At first, steam shipping experienced a remarkable boom. During this heyday, which lasted only for a short time, the number of steamboats grew to nine. Due to the Bamberg – Würzburg – Frankfurt railway line, which went into operation in 1854, and the difficulties caused by the mostly insufficient depth of the fairway in dry summers, shutdown periods often lasted for days, sometimes even months. Shipping traffic fell sharply and thus became unprofitable, in 1858 it was finally given up completely. The port basin, which had led to a considerable narrowing of the river profile and was no longer needed after the shutdown of shipping, was backfilled in 1861. Between the port embankment and the opposite retaining wall of the glacis embankment there was only a flow width of almost 100 meters. As a result, when a major flood drained, there was a considerable amount of damming. A slight increase in the water level resulted when the water level was low by moving the bank forward. The flood discharge conditions after the removal of the port were almost the same as before the port was built.
The city was defused in 1871
The population in Würzburg was eagerly awaiting the fortification of their city. This took place on a very large scale, which also brought considerable changes to the banks of the Main. A quay wall was built on the right bank above the swan gate, also known as the mirror gate, which dates back to 1584 . On the left bank, debris deposits began in 1871 to raise the Tivoli bastion to just above the thick tower . A narrow dam was built in front of the star bastion . This connected the previously separate banks with one another. The steeply sloping embankment remained unsecured. The backfills ended about 100 meters above the gauge profile and were up to 2.5 meters high in places. This conversion work had an impact on the water levels at the gauge. The higher water levels were primarily influenced.
Port construction from 1874 to 1877
During the softening work, the moat on the right Main Main, which had previously been used as a winter harbor, was filled in along its entire length. As a replacement, an efficient port was built on the right bank a little below the Pleichach estuary, today's Old Port .
In order to create enough space for the port facilities, the Main had to be completely relocated to the left foreland over a length of around 700 meters. There a new channel was dug and partly blasted out of the rock. For the expansion of the harbor basin, a number of old weir structures, which had adversely affected the water level, had to be removed from the course of the river. The embankment was filled with the excavated material. The embankment was then paved and a berm was built again for towing.
In 1877 the breakthrough took place at the new river channel. The harbor dam was extended to land in the same year. The former course of the river was sealed off. A pull path had meanwhile been laid out on the left bank. This was extended to Oberstrom, led around the Dicken Turm and connected to the backfills that began in 1871. This created a convenient route to the lock in the circulation canal for towing ships . According to the earlier expansion regulations, the height of the draw path was two meters above low water. On the right bank a new bank system was built at the same time as the old ship wintering was filled. The redesign of the banks of the Main in the area of the gauge was thus completed for the time being.
The construction work on the old port led to great concern about the water levels. For the period from January 1, 1875 to March 31, 1876, the Margetshöchheimer gauge , located seven kilometers below the Würzburg gauge, was avoided . However, this showed irregularities due to the work on mean water regulation. There are no water level lines for the Würzburg gauge for this period .
After the Main had been diverted into its new channel, the low water level sank by about 40 centimeters. Due to the narrowing of the profile, however, the damming predominated at higher water levels. The flood discharge was influenced very negatively by the construction of the port, as the flood flow, caused by the fortress wall on the left bank and the retaining wall, was directed directly onto the embankment in the same direction as the glacis embankment. These extremely unfavorable hydrological conditions can be clearly seen in the course of the water level during the flood of 1882. The harbor dam caused an enormous damming effect. On the right bank of the Main, the water level fixations carried out at that time measured a water level 30 centimeters higher than on the left bank of the Main.
Construction of the Luitpold Bridge from 1886 to 1888
In order to continue the new Ringstrasse (Röntgenring) to the Zellerau on the left of the Main, it was necessary to build a bridge over the river. The Luitpold Bridge , today's Friedensbrücke , was built from 1886 to 1888 . Presumably in the summer of 1883 the fortifications on the left bank of the Main that were disturbing the flood discharge were demolished, the moat was filled in and the area leveled. The bridge crosses the Main at an angle and the piers are also at an angle to the direction of flow. Nevertheless, overall there was a clear improvement in the flood discharge compared to the state before 1883. The bridge piers caused a damming during flooding, but this hardly had any effect on the flood level of the level, which is 550 meters above the bridge.
Construction of the quay wall from 1896 to 1898
In the years 1896 to 1898, a quay wall on the left bank from the corner bastion to the Tivoli bastion protected the unsightly earth embankment, which was at risk from flood attacks. The wall was pushed very far into the river in order to achieve a damming by restricting the width of the water table. The aim was to improve the inadequate fairway conditions in this area. A road was built on the newly created bank, which was free of vegetation.
The construction of the quay wall caused a damming of the Main, which was mainly noticeable in the higher discharge area. With a water flow of about 600 m³ / s (mean water about 122 m³ / s), the discharge curve showed a significant bulge. The retention of the water was about 15 centimeters.
Fairway dredging 1900
Despite the improvement in the fairway conditions due to the new quay wall, the fairway depths were not yet sufficient. In 1900 extensive dredging was therefore carried out in order to create better navigation conditions for shipping. The entire gravel layer, up to one meter thick, was removed. In the low water area, the water level then fell by around 30 centimeters in the following years.
Construction of a sewer culvert in 1901/1902
The construction of a sewer culvert below the Luitpold Bridge caused great concern for the water levels at the Würzburg gauge . The work had to be carried out in accordance with the state of the art at the time, with the help of containment dams in the dry, which were installed in sections with due consideration for shipping. For the years 1900 to 1902, due to the severe impairment of the water levels during the construction work, the discharge determinations were carried out at the Margetshöchheim gauge .
Construction of the Erlabrunn barrage from 1932 to 1935
The construction of the Erlabrunn barrage near Main-kilometer 241.20 began in 1932. Initially, the water level conditions at the Würzburg gauge ten kilometers above remained unaffected. After the traffic jam in Erlabrunn was built in 1934, the low water level at the Würzburg gauge was increased by around 40 centimeters. However, this dam influence was small and only extended to about the mean water.
Partial dredging of the large shipping channel in 1937/1938
In the years 1937/1938, the underwater dredging was initially only carried out as far as the old port . As a result, it was connected to the shipping channel coming from Unterstrom. The river bed was wedged out above the harbor. A transition was made across the stretch from the Old Harbor to the Luitpold Bridge, in order to get from the deep bottom of the shipping channel to the natural river bottom. The lowering of the water level that then took place only had an effect at higher water levels due to the impact of the water level in the Erlabrunn stage . In the reading range between 200 and 300 centimeters, the lowering of the water level at the gauge was about 15 centimeters.
Construction work on the river bed from 1948 to 1954
The work interrupted by the war was resumed in 1948. The construction work on the weir and the lock initially had no effect on the water level at the gauge. Before that, the sewer culverts from 1901/1902 had to be lowered. In 1952/1953 the 450 meter long quay wall on the left bank was moved back 5 to 14 meters, creating a ship's berth in the underwater. During the construction work, the old wall remained as protection for the excavation pit. The dredging of the large shipping channel in the underwater, including the rock chiseling work, lasted from 1952 to 1954. In places, the rock bed was chiseled out up to two meters.
The remaining transverse ribs in the dredged shipping channel prevented the water from sinking too much and ensured sufficient fairway depth, especially at the small lock. Only after the new lock was opened to shipping were these ribs removed. After removing the last transverse rib and demolishing the old quay wall, the water level sank considerably. The lowering had only a minor effect at low tide due to the impact of the Erlabrunn reservoir. The maximum drop at a water level of around 300 centimeters was around 60 centimeters. The value decreased with increasing water flow and was only 30 centimeters at the flood in 1970.
With the traffic jam in Erlabrunn, the low water level at the Würzburg gauge has fallen by around 200 centimeters as a result of the construction work since 1823. In the stowed state, the lowering is still around 100 centimeters. The dredging work for shipping near the gauge had no effect on the water level.
Fairway expansion 1988/1989
As part of the Main expansion, extensive dredging was carried out in the Erlabrunn dam in 1988/1989 . The Main was expanded to a fairway width of 40 meters and a fairway depth of 2.9 meters. The navigation channel was widened and deepened in the underwater area of the Würzburg barrage. The pillars of the Luitpold Bridge, which was renamed Friedensbrücke after the Second World War , were sheathed as collision protection for ships. The culverts that cross the Main and act as a basic sill were removed. The resulting lowering of the water level made it necessary to lower the highest shipping water level at the Würzburg gauge from 380 to 330 centimeters.
Structures in the area of the level
Lock systems
Weir
By order of the bishop, a commission of the council inspected the conditions at the Old Main Bridge during the Thirty Years War on March 3, 1643 with the prince-bishop's master builder Kaut and a Frankfurt mill master in order to build a flow mill there. For the mill, a weir in the Main was needed to drive the mill wheel .
On the advice of the mill master, a weir about 300 meters long and 1.2 meters high, running diagonally and ending at the third pillar of the bridge on the right bank, was built in 1644. The upper end of the weir is located on the mill bastions protruding 260 meters above the bridge far into the Main . The upper edge of the strike weir was between 168.03 and 168.10 meters above sea level. To the right of the pillar of the bridge, in the opening of the bridge, was the needle weir . The Floßgasse connected to Unterstrom. In contrast to most conventional weirs, the Würzburg weir is inclined to the direction of flow and has an unchangeable crown. This type of weir is called a strike weir.
Primarily, however, the weir was built for reasons of fortification. The closure of the fairway and the only possibility of bypassing the weir, the bypass canal that led through the outer works of the Marienberg Fortress, depended on the fort's ownership. As a result of this damming up, the flow conditions changed, as almost the entire normal flow rate was diverted to the mill.
The strike weir was repaired in 1724 and 1729 under the direction of Balthasar Neumann . In 1890/91, Kote raised the defensive back of the stretcher weir with a wooden attachment by about 25 centimeters to 168.28 to 168.35 meters above sea level. During this construction work, the lower part of the weir was relocated to the fourth bridge pillar to enable a further bridge opening for a new raft lane with a drum weir. This created a kink in the weir system 95 meters above the bridge. During the construction of the large shipping lock in 1953, the weir was raised again to 168.5 meters above sea level with an even cap made of stone and concrete.
Needle weir
A needle weir was built in the third arch of the bridge, known as the weir hole , in order to bypass the weir , which was built in 1644 and blocked the passage of ships and rafts . By pulling the needles, the Main descended above the weir, making it possible for rafts and ships to pass. After the needles were inserted, the level slowly rose again. This practiced procedure was very tedious and lengthy. Ships used this method for about 40 years and then used the orbital canal . However, the several hundred rafts a year still had to use the needle weir because they could not use the lock in the circulation canal due to their length . In order to guarantee guidance for the ships and rafts below in the strong current of the bridge, wide stone dams were added to both pillars of the bridge. Downriver the needle weir was passed by means of the current, ships traveling upriver had to be pulled into the upper water against the strong current with ropes and horses.
About three times a week, from 1 p.m., white and board rafts were let through. So-called Dutch rafts, which, as the name suggests, had a long journey ahead of them and carried valuable hardwood, were allowed to pass the weir at any time. Passing the weir took about four to five hours. During the passage process, the retention area ran empty and the underwater swelled considerably. When the weir was closed and the reservoir was refilled, the water in the underwater fell sharply, so that it was often missing for hours for shipping. The water level only normalized again after the water level was fully blocked and the mills started up. The needle weir was repaired by Balthasar Neumann in 1724 and 1729 and used until 1892. It was renovated in 1894/95 and rebuilt in 1934 during a further renovation. It was then only used for flood drainage and was in operation until 1948. It was replaced by a flap weir , also known as a fish-bellied flap, with an electric drive. In this type of weir, the water level is created by a movable flap.
For the gauge, the related concern about the low water discharge was of interest. During the long period of water level monitoring and the use of the needle weir, there were noticeable changes in the water level in the observation lists, albeit not too often. However, these discharge values could be corrected by comparing them with neighboring gauges.
Bypass channel
From 1675 to 1680 a bypass canal or circulation canal was built to facilitate the passage of ships. This shipping canal bypassed the weir and the mill for a length of about 500 meters. It began above the Burkharder Tor , passed behind the Burkharder Church , which therefore had to be shortened by two yokes , and flowed back into the Main below the weir. In the circulating canal, in which there was also a mooring, a lock system with wooden gate locks on both sides was built 47 meters long and 6.5 meters wide to bridge a height of 1.2 meters. For the shipping traffic, which was important at the time, the passage through the narrow canal was a very difficult route because of the insufficient water depth and the low headroom. A channel ran from the circulating canal, on which the canal mill was located. In 1892 the old lock in the circulation canal was abandoned and demolished in the 1920s due to its dilapidation. During the construction of the large shipping lock, the circulation channel was filled in in 1953 except for a small part at the upper corner bastion .
Small lock
In order to avoid the arduous route through the circulation canal and to speed up the passage of the rafts through the weir, the Royal Building Authority decided to build a small lock on the Streich weir and another opening for raft traffic on the Old Main Bridge . In the years 1891 and 1893 the now dilapidated small lock was built above the Old Main Bridge . It was 55 meters long, 10.5 meters wide, had a depth of about one meter and could be used by ships with a lifting capacity of up to 600 tons. For the construction of the small lock , the southern end of the stretcher weir and the mill bastion protruding into the Main had to be cut off in order to gain space for the system.
Large lock
From 1950 to 1954 the large shipping lock , which is still in use today, was built next to the small lock . This work turned out to be difficult because the Old Main Bridge is a listed building and with its not-too-wide arches 18 meters wide, which were also quite low, represented a major obstacle for the large ships. The decision was made to build the large lock above the bridge and to connect the lower inlet directly to the bridge opening. The fairway therefore had to be lowered considerably below the bridge and provided with tail units . In the upper area of the lock, the mill bastion had to be partially demolished and shortened by 15 meters inland to ensure safe entry. The lock is 300 meters long and 12 meters wide.
Drum weir
A drum weir was built in the fourth arch of the bridge in 1891/92 to cope with the increased raft traffic . This drum weir is a completely new weir lock for the time. The drum weir consists of a two-wing iron flap 10.8 meters wide and an original total height of 4.1 meters. The flap rotated on a horizontal axis. When the flap is raised, the upper half blocks the passage of the weir and the lower half is enclosed in a cavity under the base of the weir called the drum . In addition, a new raft lane was built , led by two dams each 125 meters long . With the new drum weir, the water fluctuations in the underwater and the adverse effects on shipping could be greatly reduced. The drum weir allowed the breech to be opened and closed quickly. In 1934/35 it was converted to a higher stowage and in 1970 also replaced by a flap weir ( fish belly flap ).
Mills
The operation of the mills has an influence on the flow conditions of the Main and a disturbance of the water in the area of the level, primarily during the low water discharge. When the water is low to medium, when the mill is in operation, almost all of the water runs off through the mills instead of through the weir. The operating status and the corresponding control of the inflow and outflow of water also influence this.
Lower Main Mill
During the construction of the Streichwehr in 1644, the Untere Mainmühle was also built on the right bank of the Main, below the Old Main Bridge . The inlet of the mill, which was located under the second arch of the bridge, had a channel 5.5 meters wide, which drove four wheels, each 2.2 meters wide and five meters in diameter. One of the mill wheels was removed in the 19th century. Below the mill was a water-powered hammer forge with three tail hammers, which was built around 1680. There was also a bathing establishment with a wave pool by the mill.
Lower Mainmühle power plant
When the Rhein-Main-Donau-AG acquired the water rights of the mills in 1921 , the Lower Main Mill was demolished. At this point, the construction of a new power plant began. The construction of the power house was completed in August 1922. The wings of the building that adjoin the bridge were built between autumn 1922 and July 1923. The power plant was equipped with two Francis turbines , which supplied electricity to Würzburg. During this construction work the hammer forge and the wave pool had to give way. The mill below the weir needed almost all of the water from the Main, which was drained through the bridge opening to the mill. During the operation of the needle weir, the mill operators had to cease operations, which at the time led to complaints and friction between those involved.
The Untere Mainmühle power plant was modernized between 1950 and 1952 and received new machines. Extensive renovation work took place in 1987/1988. The power plant was automated and equipped with three powerful Kaplan bulb turbines .
Upper Main Mill
The Streichwehr generated considerable water power, so that the Obere Mainmühle or Hoffmannsmühle at the Mühlbastion could also be operated on the left side of the Main . This was built under Prince-Bishop Johann Philipp von Schönborn , who had also built the Untere Mainmühle , in the years 1656/1657. The mill was equipped with a pressure unit for supplying water to the Marienberg Fortress and the Hofbräuhaus (then owned by the Prince-Bishop). It was destroyed in the air raid on Würzburg on March 16, 1945.
Canal mill
The construction of the bypass canal was used to build a third mill, the canal mill on Burkarderstraße, in 1676 . This was made possible by draining a channel into the bypass canal above the canal lock, which led to Burkarderstrasse and then back to the underwater area of the canal. The mill had three large undershot water wheels , with the water flowing through below the center of the wheel and driving the blades of the wheel. It was also connected to the water supply of the fortress and the Hofbräuhaus. The mill was used until 1927. It was destroyed during the air raid on Würzburg. The ruins were removed when the large shipping lock was built.
bridges
The pillars of the bridges cause a certain amount of damming of the Main and influence the flow conditions. After prolonged periods of frost and subsequent ice discharge, damming occurs there. During floods, driftwood wedged on the pillars can also lead to a build-up and change in the flow conditions.
Old Main Bridge
The Alte Mainbrücke is one of the oldest bridges on the entire Main. The first building dates back to the 12th century (first mentioned in 1133). During floods, for example in 1306, 1342 and 1442, the bridge was completely or partially destroyed several times. The flood of 1784 also damaged the bridge. The fourth and fifth arches were blown up on April 2, 1945 by the retreating German troops. After the Second World War , American pioneers built a temporary bridge with steel girders over the destroyed section to allow the population to cross the Main again to a limited extent. The bridge was rebuilt from April to July 1950. A flood relay has been located on it since 1823.
Luitpold Bridge
As a result of the sharp increase in traffic, more efficient bridges were built in the second half of the 19th century as the softening progressed. The Luitpold Bridge , today's Friedensbrücke , was built downstream of the level in 1886 and opened to traffic in 1888. It consists of seven arches supported by six pillars. Towards the end of the Second World War, the bridge was destroyed and rebuilt after the war. The debris caused a strong build-up of the Main, which influenced the level. The bridge was widened to adapt to the traffic until 1999 and the two pillars standing in the water were encased with a collision protection for ships. These pillars are not a harmless obstacle for shipping, but also cause a small amount of backlog.
Ludwigsbrücke
After the softening on the south side, which progressed more slowly than on the north, another bridge was built in 1896. The planning of the Ludwigsbrücke , popularly known as the Lion Bridge because of the four large lion statues on the two driveways , began in April 1885. The plans go back to the year 1882, due to the construction work on the Ringstrasse, which had been extended to the Main. The bridge has five arches, each 36 meters wide, two of the four bridge piers are in the Main. The stone bridge was also destroyed towards the end of the Second World War and was later rebuilt entirely in its former state.
Flood
| Flood annuals | |||
|---|---|---|---|
| Annuality | Value at the level | ||
| Drain | Height in cm | ||
| HQ 1 | 540 m³ / s | 387 | |
| HQ 2 | 700 m³ / s | 450 | |
| HQ 5 | 920 m³ / s | 526 | |
| HQ 10 | 1130 m³ / s | 586 | |
| HQ 20 | 1400 m³ / s | 650 | |
| HQ 50 | 1700 m³ / s | 708 | |
| HQ 100 | 2000 m³ / s | 767 | |
| HQ 200 | 2300 m³ / s | - | |
| HQ 300 | 2500 m³ / s | 884 | |
| HQ 500 | 2700 m³ / s | - | |
| HQ 1000 | 3000 m³ / s | - | |
Flood annuals
The frequency with which a water level or discharge volume is reached or exceeded at the gauge is called the annuality. Based on these values and by adapting a distribution function, the maximum discharge (HQ) can be determined up to a thousand-year flood. At the Würzburg gauge , these values were determined from the observation period from 1901 to 1997. The annualities determined in this way can only be compared with the older flood events for runoff. Since the structural changes in the area of the water level are now significantly lower with the same discharge, it can be concluded that the earlier flood events reached higher water levels with the same annuality.
Reporting levels
The start of the flood detection starts at a level of 290 centimeters. At 340 centimeters at the level, the high water mark I is reached, at which the shipping traffic is stopped. The high water mark II is reached at a level of 400 centimeters. High water mark III is reached at a level of 510 centimeters and high water mark IV from 600 centimeters.
The Main overflows its banks from a level of 300 centimeters. The parking lot at the Löwenbrücke is flooded from a water level of 340 centimeters at the gauge . At 360 centimeters, the railway underpass to the New Harbor is flooded. From a water level of 380 centimeters, the provisional flood protection at the Mainkai is necessary. The lower Ludwigkai is flooded from 410 centimeters at the level and flood protection at the Kranenkai is required from a level of 475 centimeters. At 480 centimeters, the provisional flood protection on Mainkai is flooded at the Alte Mainbrücke passage and flood protection on Karmelitenstrasse is required. At 500 centimeters, the underpass at the Lion Bridge is flooded and at 520 centimeters, the Obere Mainkai is flooded. From 530 centimeters upwards, Pleichtorstrasse, Karmelitenstrasse and Gerberstrasse are flooded. At a water level of 570 centimeters, the Seilerstraße, Maingasse and Mühlengasse and from 590 centimeters on Mergentheimer Straße near the old Main Bridge are flooded. From 650 to 670 centimeters, the provisional flood protection, which protects the more central part of the city, is flooded. Untere Domstraße and the confluence with Augustinerstraße are flooded from a water level of 710 centimeters.
Flood times
An undeformed flood wave on the Main needs about one and a half to two days to get from Trunstadt and the water level there below the Regnitz confluence to Würzburg. From Schweinfurt to Würzburg, the duration of the wave for the 78.8 kilometer stretch of the river averages 21 hours. This period of time offers the city of Würzburg the opportunity to estimate the level of the flood and react accordingly.
At the next level near Steinbach, which is 51.4 kilometers downstream, it takes seven to eight hours for the flood wave from Würzburg to arrive there. The Würzburg gauge includes the intermediate catchment areas 969.20 km² downstream to Steinbach and 1051.70 km² upstream to the Astheim gauge , which, depending on how strong the flood waves of the tributaries up the Main are pronounced and coincide with the peak of the Main, influence the flood wave.
Flood protection
The city of Würzburg has been hit by devastating floods several times over the past centuries. These extended several times to the town hall, but also occasionally up to the cathedral. The 20-year flood in 1970 caused great damage. Due to this event, the city of Würzburg, represented by the Würzburg Water Management Office , applied to the Free State of Bavaria for the construction of flood protection to protect the old town area on the right-hand side of the Main between the Friedensbrücke and the Löwenbrücke . The left Main and the other areas on the right Main are mostly higher.
The first provisional flood protection dates from 1983 and was designed up to a level of around 650 to 670 centimeters. This corresponds roughly to a 20-year flood. Since then, the city has endeavored to protect the endangered urban area with an area of around 25 hectares, in which around 3000 people live, against a 100-year flood, which corresponds to a water level of 835, roughly the flood of 1845.
The costs for the complete flood protection amount to around 18 million euros, with the Free State of Bavaria assuming 67 percent. The flood protection in Würzburg was completed by 2008.
Ice conditions
Because of its shallow water, the Main used to have a strong tendency to freeze. Because of the shallow depth, the water quickly undercooled. Beginning in areas of the river with weak currents, extensive drift ice and ground ice formations occurred with persistent frost. The drifting ice masses often filled the entire width of the river until they came to a standstill at a narrow point. The ice level moved rapidly upstream with the continued supply of drift ice. The icing usually also led to an increase in the water level, the so-called ice jam . Slight swelling usually triggered the break-up and departure of the ice. If the ice flow was interrupted by a sudden onset of frost, it sometimes resulted in ice dislocations with considerable accumulation.
The ice stagnation in Würzburg increased due to considerable ice masses after the construction of the barrage in Erlabrunn in November 1934. The ice drifted from the Main stretch exposed above the barrage and came to a standstill in the dammed water below Würzburg. The ice floes pushed themselves over and under each other and often filled the entire width of the river. In the particularly severe winters of 1939/1940, 1940/1941 and 1946/1947, the water levels at the Würzburg gauge were also heavily influenced by the ice jam. When the barrages above Würzburg were completed and thus the supply of drift ice was cut off, the situation improved. The Würzburg – Ochsenfurt main line with three barrages was opened in 1954.
During a period of frost on the Main, closed ice sheets immediately form in the individual reservoirs above the weirs. This ice cover can grow quickly over the entire length of the dam. The ice cover protects the pent-up water masses in the individual sections from excessive hypothermia and acts as a heat store, so that no noteworthy drift and ground ice is formed. In the dammed Main, with the same frost situation, significantly less ice is created than in the past when it was not blocked. This effect is supported by the heating of the Main water as a result of the increasing sewage and hot water discharges.
Flood events
The flow conditions and the resulting water levels changed over time. Due to the constant expansion of the Main, the discharge increases with the same water level. With the same high water peak today and at the beginning of the measurement series, more water can flow off today. The flood of January 20, 1841, with a discharge of 1318 m³ / s, reached a water level of 709 centimeters. About 160 years later and after many structural changes in and on the river, the flood of January 6, 2003, with a slightly higher discharge of 1350 m³ / s, reached a level of 648 centimeters. Accordingly, the number of high water levels has decreased.
At the Würzburg gauge , six floods (three in the 19th and three in the 20th century) reached a discharge of more than 1500 m³ / s; however, the value in the 20th century was significantly lower than in the previous century. A total of 24 floods reached a discharge of 1000 m³ / s, 14 of which occurred in the 19th and only 9 in the 20th century. In total, the seven-meter mark has been exceeded ten times since 1823, seven times in the 19th and three times in the 20th century.
For detailed information on historical floods in Würzburg, see Floods in Würzburg .
| Water levels from a discharge of 1000 m³ / s |
|||
|---|---|---|---|
| date | Value at the level | Return time |
|
| cm | m³ / s | ||
| −−.−−. 1827 | 650 | 1150 | 10–20 years |
| 04/01/1830 | 675 | 1200 | 10–20 years |
| 03/06/1831 | 705 | 1295 | 10–20 years |
| −−.−−. 1834 | 635 | 1050 | 5–10 years |
| −−.−−. 1839 | 675 | 1200 | 10–20 years |
| 01/20/1841 | 709 | 1318 | 10–20 years |
| 02/28/1844 | 652 | 1100 | 5–10 years |
| 03/30/1845 | 834 | 2170 | 100-200 annually |
| 06/02/1845 | 686 | 1200 | 10–20 years |
| 02/10/1848 | 688 | 1220 | 10–20 years |
| 02/05/1850 | 710 | 1320 | 10–20 years |
| 02/02/1862 | 732 | 1454 | 20–50 years |
| 02/19/1876 | 750 | 1580 | 20–50 years |
| 04/01/1880 | 652 | 1100 | 5–10 years |
| December 17, 1880 | 638 | 1040 | 5–10 years |
| 03/09/1881 | 631 | 1020 | 5–10 years |
| 11/28/1882 | 728 | 1460 | 20–50 years |
| 12/29/1882 | 749 | 1670 | 20–50 years |
| 02/07/1909 | 760 | 1800 | 50–100 annually |
| 01/16/1920 | 721 | 1540 | 20–50 years |
| March 22, 1942 | 640 | 1050 | 5–10 years |
| December 31, 1947 | 702 | 1540 | 20–50 years |
| 02/25/1970 | 669 | 1390 | 10–20 years |
| 01/07/1982 | 637 | 1230 | 10–20 years |
| March 29, 1988 | 640 | 1235 | 10–20 years |
| 01/29/1995 | 615 | 1250 | 10–20 years |
| 01/06/2003 | 648 | 1350 | 10–20 years |
| January 17, 2011 | 642 | 1368 | 10–20 years |
Historical floods
Based on the records of historians from earlier centuries, which describe the flood flow, the ice conditions and the damage caused, and the high water markings attached to buildings on the Main, some of the highest water levels in the last 700 years or so could be determined.
The highest flood on the Main and in Würzburg was that of 1342, also known as the Magdalene flood . In relation to the level, this flood had a level of 950 to 1030 centimeters with a discharge of 3050 to 3600 m³ / s. This event is known as a flood lasting more than a thousand years. More recently there was an extreme flood on February 29, 1784, with a water level of 928 cm and a discharge of 2600 m³ / s. This event is classified as an approximately 500-year flood.
Due to the structural changes in the area of the water level, the historical annual figures are only based on the runoff, as the water levels at that time were significantly higher than today and would therefore lead to incorrect annualities.
| Historical floods | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| date | Value at the level | Return time |
||||||||
| cm | m³ / s | |||||||||
| 07/21/1342 | 1000 | 3350 | > 1000 annually | |||||||
| 02/24/1451 | 840 | 2200 | 100-200 annually | |||||||
| 01/24/1546 | 860 | 2300 | 200 annually | |||||||
| 05/16/1573 | 760 | 1650 | 20–50 years | |||||||
| −−. 03.1595 | 840 | 2200 | 100-200 annually | |||||||
| 01/25/1633 | 790 | 1900 | 50–100 annually | |||||||
| 01/27/1682 | 863 | 2250 | 100-200 annually | |||||||
| 03/05/1744 | 720 | 1400 | 20 years | |||||||
| 01/01/1764 | 805 | 1750 | 50–100 annually | |||||||
| 02/29/1784 | 928 | 2600 | 300–500 annually | |||||||
| 01/21/1820 | 720 | 1350 | 10–20 years | |||||||
literature
- Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Böhler Verlag, Würzburg 1999.
- Franz Seberich: The old Main Bridge to Würzburg. Mainfränkische Hefte, Heft 31, Buchdruckerei Karl Hart, Volkach vor Würzburg, Würzburg 1958.
- Martin Schmidt: Floods and flood protection in Germany before 1850. Commission publisher Oldenbourg Industrieverlag Munich, Munich 2000, ISBN 3-486-26494-X .
- Wasser- und Schifffahrtsdirektion Süd (Ed.): Information - Main - Main-Danube Canal - Danube. Printing and publishing house Pius Halbig GmbH, Würzburg 1997.
- Heinz Schiller: Determination of flood probabilities on the navigable Main and supra-regional comparison of the results. in information reports of the Bavarian State Office for Water Management, Munich 1989.
- Rüdiger Glaser : Historical floods in the main area - possibilities and perspectives on the basis of the historical climate database Germany (HISKLID). in Geographical Studies in Erfurt, Volume 7, 1998.
- Bavarian State Office for Water Management (Ed.): Spectrum Water 1 - Flood - Natural Event and Danger. University printing and publishing house Dr. C. Wolf & Sohn GmbH & Co. KG, Munich 2004, ISBN 3-930253-93-3 .
- Franz Seberich: The city fortifications of Würzburg II. Mainfränkische Hefte, booklet 40, hard print Volkach before Würzburg, Würzburg 1963.
Web links
- Würzburg gauge at Würzburg.de ( Memento from November 8, 2007 in the Internet Archive )
- Würzburg gauge at the flood intelligence service - Bavaria (HND)
- Würzburg gauge at the Electronic Waterway Information System (ELWIS)
- Würzburg gauge at the Federal Institute for Hydrology (BFG)
- Würzburg flood protection at the Aschaffenburg water management office
- Würzburg drainage plant (EBW)
- Flood action plan Main
Individual evidence
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 43.
- ↑ a b c d Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 9.
- ↑ a b c d e f Würzburg / Main water level. Retrieved March 9, 2019 .
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 46.
- ↑ a b Flood news service - Bavaria, master data ( Memento from September 9, 2007 in the Internet Archive )
- ↑ Master data of all Main locks - Waterways and Shipping Directorate South ( Memento of the original from June 13, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Electronic Waterways Information System (ELWIS) ( Memento from July 13, 2010 in the Internet Archive )
- ↑ European shipping and port calendar - WESKA 2002. Page A 793.
- ↑ a b Lexicon at the flood news service ( Memento from May 15, 2007 in the Internet Archive )
- ↑ a b City of Wuerzburg: Topics | Environment and climate | Water and Soil - Floods and Floods. Retrieved March 9, 2019 .
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 52 and 53.
- ↑ a b c d Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 10.
- ↑ a b Flood news service - Bavaria, discharge table ( Memento from September 8, 2007 in the Internet Archive )
- ↑ a b c d e f Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 38–39.
- ^ Franz Seberich: The old Main Bridge to Würzburg. Page 181.
- ↑ a b Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 37–38.
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 37.
- ↑ a b Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 11.
- ↑ a b Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 34.
- ↑ a b c Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts.
- ^ Franz Seberich: The city fortifications of Würzburg II. Pages 165 and 172.
- ^ Franz Seberich: The city fortifications of Würzburg II. Page 195.
- ↑ Stefan Kummer : Architecture and fine arts from the beginnings of the Renaissance to the end of the Baroque. In: Ulrich Wagner (Hrsg.): History of the city of Würzburg. 4 volumes; Volume 2: From the Peasants' War in 1525 to the transition to the Kingdom of Bavaria in 1814. Theiss, Stuttgart 2004, ISBN 3-8062-1477-8 , pp. 576–678 and 942–952, here: p. 616.
- ^ Franz Seberich: The old Main Bridge to Würzburg. Pages 112–116.
- ↑ a b c Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 41–42.
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 27 and 29.
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 29.
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 29 and 41.
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 31 and 41.
- ^ Waterways and Shipping Directorate South (Ed.): Information - Main - Main-Danube Canal - Danube.
- ^ Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Pages 29 and 31.
- ↑ a b c d Franz Seberich: The old Main Bridge to Würzburg. Page 137–140.
- ^ Franz Seberich: The city fortifications of Würzburg II. Page 50.
- ^ Franz Seberich: The old Main Bridge to Würzburg.
- ↑ a b Flood news service - Bavaria, flood marks ( Memento from September 9, 2007 in the Internet Archive )
- ↑ Threats and Measures - Flood Intelligence Service ( Memento from November 19, 2004 in the Internet Archive )
- ↑ a b Flood news service - Bavaria, area data / transit times ( Memento from September 9, 2007 in the Internet Archive )
- ↑ Aschaffenburg Water Management Office, Würzburg flood protection ( Memento from July 1, 2007 in the web archive archive.today )
- ↑ Page no longer available , search in web archives: Chronology of flood protection
- ↑ a b c Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 39.
- ↑ Bavarian State Office for Water Management (Ed.): Spectrum Water 1 - Flood - Natural Event and Danger. Page 57–59.
- ↑ a b c Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 52.
- ↑ a b Wasser- und Schifffahrtsdirektion Süd (Ed.): 175 years of the Würzburg gauge - data and facts. Page 53.
- ^ Franz Seberich: The old Main Bridge to Würzburg. Page 179-180.
- ^ Bavarian flood news service. State Office for the Environment, accessed on January 19, 2011
- ^ A b Franz Seberich: The old Main Bridge to Würzburg. Page 177-181.
- ↑ a b Martin Schmidt: flood and flood protection in Germany before 1850. Page 275th
- ↑ a b Heinz Schiller: Determination of flood probabilities on the navigable Main and supra-regional comparison of the results. Page 224–232.
- ↑ Magdalenenhochwasser at Wuerzburg.de ( Memento from January 14, 2006 in the Internet Archive ) (pdf file - 147 kilobytes)
Coordinates: 49 ° 47 ′ 46 " N , 9 ° 55 ′ 33" E
