| Only a few studies have attempted to quantify topography-depending water
fluxes, to evaluate retention and reservoir capacities and surface run-off
paths within large river basins because data availability and data quality
are critical issues to face this objective. It becomes most relevant if
water balance has to be calculated in large or transboundary river basins.
The advance of space based earth observation data offers a solution to this
information problem. Therefore, this paper mainly focuses on weaknesses and
strengths analyzing topography with SRTM (Shuttle Radar Topography Mission)
digital height data and thus provides techniques for their improved
application in river network derivation, floodplain analysis, watershed
hydrology in large as well as in large river basins (>1000 km2).
In the analysis different types of digital elevation models (DEM), terrain
models (DTM) and land cover classification data (biotope map, Corine Land
Cover 1994) have been used. The DHMs are generated from Airborne Laser
Scanning (0.5 m), topographic maps (10.0/50.0 m) and SRTM at 30.0 m and 90.0 m
spatial resolution. SRTM digital height models are generated by Synthetic
Aperture Radar (SAR) and show a high spatial variance in urban areas,
regions of dense vegetation canopy, floodplains and water bodies. As study
area serve the Elbe basin (Czech Republic, Germany) with its sub-basins and
the Saale river basin (Germany, different federal countries Saxony-Anhalt,
Saxony and Thuringia). |