Hydroscope-automated analysis of river channels and drainage basins from digital elevation models derived from stereo-SPOT images of semi-arid environments in south east Spain

By modelling the over-land flow from hill slopes to river channels using digital elevation models (DEMs), one produces a link between spatial and network representations of geographical space. After overcoming certain technical problems, one can create a "hydrotopographic engine". This forms the basis of Hydroscope a new generic tool for geographical research. This paper describes how Hydroscope has been applied to derive automatically the characteristics of stream channels and drainage basins from DEMs. It focuses on an illustration using DEMs which were derived from stereo-SPOT satellite images ofa semi-arid area in southeastern Spain. The authors argue that there is a need to develop new applications which exploit current technologies for generating high-quality DEMs over huge areas ofthe Earth's surface. They outline key characteristics of Hydroscope, a PC Windows application which uses gridded-DEMs for simulating earth surface processes. They describe an example using gridded-DEMs derived from stereo-SPOT satellite images. Lastly, they discuss the results in terms of the accuracy of grid-spacing and heighting of the specific DEM which was used.