ALPMON FINAL REPORT - ARC systems research

Contract ENV4-CT96-0359 ALPMON
framework of a hydrological modelling project because of economic and time constraints. For this
application, therefore, following procedure was applied to derive the soil type information. As the basis
for the estimation of soil-types, the soil-type map of Styria 1:1.000.000 (Krainer et al., 1998), the
geological map of Styria 1:50.000 in digital format, and point-wise available soil analysis data (Krainer
et al., 1998) were used. The result is an “estimated soil type distribution” of the catchment area, with
the 1:50.000 scale of the geological map and the soil type information of the 1:1.000.000 scale soil type
map. The so derived parameters can only give a rough estimate of the actual soil parameters.
However, major improvements on the soil type distribution information, e.g. detailed delineation of
valley bottoms, alluvial cones etc. result from this procedure.
The applied TOPMODEL approach is based on the saturated area approach using the topographic
index after Beven and Kirkby (1979). This statistically based model differs from earlier soil-vegetation
process models by including spatial variations in the main driving processes and uses topographic
HRU’s to calculate lateral soil water transport. The recession parameter m was determined by slope
hydrograph analysis. The main parameter of the TOPMODEL approach, the soil-topographical index,
has been derived from the DEM. According to the saturated area theory, a higher index indicates a
higher chance to contribute to the direct runoff. Thus, the areas with the highest indices simultaneously
represent the river network.
The first model output results for the Sulm gauge in Leibnitz are displayed in Figure 5 for the time
period from April until September 1999. Figure 5 shows the measured and simulated hourly runoff of
the basin Sulm.
Figure 5: Measured and simulated runoff for the basin Sulm from April to September 1999.
For the period April to September 1999 the Nash-Sutcliffe coefficient was determined (Nash &
Sutcliffe, 1970). The calculated “Explained Variance Coefficient” of 0.7 indicates a fair representation
of the hydrology of the Sulm catchment.
2.3.2.7 Conclusion
Distributed models such as ASGI require land cover data for parameterisation. The use of earth
observation data can be seen as an important pre-requisite for such models, as the spatial data
demand for large area applications could hardly be satisfied without earth observation derived data
sets (compare e.g. cost-estimates for land-cover mapping given by Konecny, 1995) . This leads to the
conclusion that earth observation data support the application of distributed models, thus extending the
toolbox of hydrologists.
2.3.3 Avalanche Risk Assessment, Dachstein Test Site (JR)
2.3.3.1 Introduction and Objectives
Increasing public and private construction activities have led to increased pressure on the valleys of the
Alps. In order to prohibit uncontrolled building activities in torrent and avalanche danger zones, hazard
JR, RSDE, ALU, LMU, Seibersdorf, WSL 37