Additionally, a DEM with a spatial resolution of 5 m and a ground depression
detection map were used. Since especially salt steppes and salt marshes are closely
related to the ground or sea water level, it can be assumed that ground depressions
provide a high potential for this habitat type. The same applies to littoral zones
beside the lake. However, littoral zones are not detected as ground depressions,
since the entire littoral zone is already depressed. To determine these waterside
areas, all areas between the lake’s average surface of 115.45 m and 116 m ground
elevation are taken as littoral zones.
Thresholds were applied to estimate three probability levels of inland marshes
(Fig. 7.3). These thresholds are derived from reference habitats to deduce high,
medium, and low habitat occurrence probabilities. Only land-cover types with a
realistic potential for inland marshes were considered for the application of the rule
set. CORINE land-cover data were used to mask out land-cover classes with little
potential (e.g. urban areas).
7.3.3 Results
The results depicted in a habitat probability map (Fig. 7.4) show a transition from
Lake Neusiedl in the western part to small probability patterns approximately
10 km from the main water body.
As expected, areas with the highest probability of occurrence can be found close
to the lake. However, because of the low overall variation in altitude the possibility
of detecting small depressions is a key feature for salt marshes. Therefore,
Fig. 7.3 Hierarchical classification approach for mapping of potential occurrence of inland
marshes
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M. Fo ¨rster et al.
detection map were used. Since especially salt steppes and salt marshes are closely
related to the ground or sea water level, it can be assumed that ground depressions
provide a high potential for this habitat type. The same applies to littoral zones
beside the lake. However, littoral zones are not detected as ground depressions,
since the entire littoral zone is already depressed. To determine these waterside
areas, all areas between the lake’s average surface of 115.45 m and 116 m ground
elevation are taken as littoral zones.
Thresholds were applied to estimate three probability levels of inland marshes
(Fig. 7.3). These thresholds are derived from reference habitats to deduce high,
medium, and low habitat occurrence probabilities. Only land-cover types with a
realistic potential for inland marshes were considered for the application of the rule
set. CORINE land-cover data were used to mask out land-cover classes with little
potential (e.g. urban areas).
7.3.3 Results
The results depicted in a habitat probability map (Fig. 7.4) show a transition from
Lake Neusiedl in the western part to small probability patterns approximately
10 km from the main water body.
As expected, areas with the highest probability of occurrence can be found close
to the lake. However, because of the low overall variation in altitude the possibility
of detecting small depressions is a key feature for salt marshes. Therefore,
Fig. 7.3 Hierarchical classification approach for mapping of potential occurrence of inland
marshes
102
M. Fo ¨rster et al.