Lake Constance Basin

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The on Lake Constance and especially its north location Lake basin is one of the Rhine glacier glacial dominated landscape in the southern German states of Baden-Wuerttemberg and Bavaria , and, depending on the interpretation, in the northeast of Switzerland and in the Western Austrian Vorarlberg . According to the systematics of the manual of the natural spatial structure of Germany , it is designated as natural area main unit 031 in the foothills of the Alps and moorland ( main unit group and greater region 2nd order 03, southern foothills of the Alps ).

location

The Lake Constance basin lies between the Upper Swabian hill country in the north, the Hegau in the west and the West Allgäu hill country in the east. The km² in Baden-Württemberg without Lake Constance 590, according to senior boundaries throughout Germany 747.76 sq km area covers parts of Lake Constance district and the counties Ravensburg and Lindau . The basin landscape frames the lake in varying widths, especially at Ravensburg very spacious, and extends up to a height of 500  m above sea level. NN . It is drained via the Rotach , Schussen and Argen and their tributaries and Lake Constance to the Rhine .

History of the named natural area

In the first delivery of the handbook of the natural spatial structure of Germany in 1953, the natural spatial main unit 031 Lake Constance basin was identified, whose western border to the neighboring unit 030 Hegau ran along a line between Radolfzell and Stockach . This border direction was also followed to the south, so that, according to that structure, the Schiener Berg also belonged to the unit. In the south, the natural area ended directly on the shore of the lake or just contained the area of ​​the city of Bregenz . According to the delimitation mentioned, the Lake Constance basin within Germany was 747.76 km² in size. This demarcation also existed in the second mapping in 1960.

Single sheets Konstanz and Lindau

When the division of the western part was to be refined in 1964 on sheet 186 Konstanz on a scale of 1: 200,000, its author, Alfred G. Benzing, however, found that it made no sense in strictly natural terms to separate the Hegau from the Lake Constance basin, which is why it was opened his sheet defined and refined the main unit 030/031 Northern Lake Constance and Hegau Basin . His colleague Hansjörg Dongus was even more rigorous when he wrote the neighboring paper 187/193 Lindau / Oberstdorf to the east in 1991 . Dongus merged the "old" units 030 and 031 with the old units 032 Upper Swabian hill country and 033 West Allgäu hill country and defined the new main unit 030 Lake Constance-Jungmoränenland . This extends east to Adelegg and meets the old moraines of the Danube-Iller-Lech-Platte in the north ( Donau-Ablach-Platten ) and northeast ( Riss-Aitrach-Platten ) . In the west and northwest it is bounded by Randen and Hegaualb . To the south, the Lake Constance basin to Dongus also occupies the Dornbirn Rhine Valley in Vorarlberg and northeastern Switzerland, as well as the southern Lake Constance hill country in northeastern Switzerland; The latter, however, is largely on the Konstanz sheet, which does not delimit the area beyond the southern shore of Lake Constance.

LUBW

When the State Institute for the Environment, Measurements and Nature Conservation Baden-Württemberg (LUBW) tried in the immediately following years to combine the individual sheets of their federal state, which were often contradictory at the points of contact, into a coherent breakdown into main units, it was also a goal to use well-known landscape names as natural space names to preserve, which is why the main units of the manual are again listed there, within modified limits. The Lake Constance basin shrank around all parts to the west of the lake including the Schiener Berg and around the Stockacher Bergland northwest of the lake, all of which were attributed to the Hegau. It is shown within Baden-Württemberg with an area of ​​590 km² (excluding Lake Constance). North of the Überlinger See it extends west to Owingen , on the north bank of the Überlinger See even to Sipplingen .

Definition according to Dongus

“The 4th order unit includes the main basin of the Wurmzeit lichen Rheingletscher with the Obersee , the branch basins of the Untersee , the Überlinger See and the silted-up Schussen valley as well as the post- Pleistocene area of the Rhine valley between the Schrattenkalkriegel of Koblach - Oberriet and today's Rhine delta area between Bregenz and Rorschach . Connected are the low molasse and drumlin ridges near the lake, separated from the outwardly adjoining inner young moraine by circumferential channels, at altitudes of 400–500 m, only in the western part ( Schiener Berg ) also 700–600 m. "

- Hansjörg Dongus , The natural space units on sheet 187/193 Lindau / Oberstdorf (1991), p. 29.

The quote shows that, according to Dongus' definition, not only significant parts of the Hegau unit , but a large part of northeastern Switzerland would be part of the Lake Constance basin. However, since the Hegau unit has more or less established itself in its current form in Baden-Württemberg, these units are not listed here below. Since sheet 186 Konstanz does not show any other units within Switzerland (and would not be nominally responsible), other works will have to be used to describe and structure the north-east Swiss parts.

Natural structure

The finer natural areas from sheet 186 Konstanz and sheet 187 Lindau / Oberstdorf can be assigned to the main unit 031 Lake Constance basin according to LUBW as follows:

  • (on 030 Bodensee-Jungmoränenland according to Blatt Lindau, Hansjörg Dongus )
    • 031 (LUBW) = 030 / 031.0 + 030 / 031.20 + 030 / 031.4 (Benzing) = 030.0 (Dongus) Lake Constance basin

Ice edge locations in northeastern Switzerland

An important (Würm) ice edge location in northern Switzerland ran from Goldach SG via Roggwil TG to Kradolf-Schönenberg in the west-northwest direction. Not far to the north-west of Kradolf, from Sulgen TG to Kümmertshausen, there is an ice-edge boundary to the northeast that can still be seen today in the relief of the landscape, and not far to the northeast, an even more clearly recognizable, northwest-facing from Herrenhof TG via Kurzrickenbach to Kreuzlingen starts .

Interestingly, the Thur valley runs from Kradolf to its mouth at Ellikon am Rhein, recognizable within an old channel of the glacier end lake, which fits the described ice edge location and is significantly wider than the Rhine valley south of Schaffhausen . This suggests that Dongus' unit 030.02 Southern Lake Constance hill country comprises at least the basin delimited above.

The unit 030.5 Southern Bodensee-Jungmoränenland , which Dongus (p. 2) mentions as a neighboring landscape outside its leaf area, apparently includes in particular the edge heights of the basin determined by this ice edge location, which are listed below.

Between St. Gallen in the south-east and Schaffhausen in the north-west, a series of chains of hills repeatedly interrupt the undulating landscape:

The Ottenberg (681 m) north of Weinfelder , which adjoins the Seerrücken (721 m) to the south-east, is already somewhat separated from it by the gently rolling landscape.

Parts of the Lake Constance basin in Hegau

According to strictly physical and landscape genetic aspects, the two sinks within the main Hegau unit are also part of the Lake Constance basin:

Emergence

In the Würm glacial period , around 20,000 years ago, the Rhine glacier shaped the landscape. The Lake Constance basin essentially comprises the area of ​​the northern trunk basin and the most important branch basin of the glacier, the shot tongue, which is filled with gravel . Drumlins , young moraine areas and glacial molass ridges with ravines represent the typical landforms here today. In the area of ​​the ground moraines , loam and sandy loam predominate, in the meltwater channels gravel and sand.

cities and communes

According to the State Institute for the Environment, Measurements and Nature Conservation Baden-Württemberg (LUBW) and the Federal Agency for Nature Conservation (BfN), the following cities and municipalities are geographically part of the Lake Constance basin:

Lake Constance district

Ravensburg district

  District of Lindau (Lake Constance)

Protected areas

Numerous nature and landscape protection areas are designated within the Lake Constance basin, especially marshland and bog areas ( reeds ) and bodies of water ( ponds , ponds, springs). The larger of these areas, such as the Eriskircher Ried , are placed under special protection as FFH and / or European bird protection areas.

Protected area shares % Total landscape area
FFH areas 5.24
European bird sanctuaries 1.94
Nature reserves 1.91
Other protected areas 0.00
Effective proportion of the protected area 6.31

Status: 2010

Individual evidence

  1. ↑ a b Emil Meynen , Josef Schmithüsen (Editor): Handbook of the Natural Region Divisions of Germany . Federal Institute for Regional Studies, Remagen / Bad Godesberg 1953–1962 (9 deliveries in 8 books, updated map 1: 1,000,000 with main units 1960).
  2. ^ A b Alfred G. Benzing: Geographical Land Survey: The natural space units on sheet 186 Konstanz. Federal Institute for Regional Studies, Bad Godesberg 1964. →  Online map (PDF; 4.1 MB)
  3. ^ A b Hansjörg Dongus : Geographical land survey: The natural spatial units on sheet 187/193 Lindau / Oberstdorf. Federal Institute for Regional Studies, Bad Godesberg 1991. →  Online map (PDF; 6.1 MB)
  4. ↑ a b State Institute for the Environment Baden-Württemberg (LUBW) ( information )
  5. ↑ Natural area profile Lake Constance basin (031) - LUBW (PDF; 7.4 MB; notes )
  6. ↑ Hegau natural area profile (030) - LUBW (PDF; 8.7 MB; notes )
  7. ↑ GeoViewer of the Federal Institute for Geosciences and Raw Materials ( information )
  8. ↑ Geoserver of the Swiss Federal Administration ( information )

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