干旱区生态环境知识资源中心

Into the framework of the Almanzora*GIS project, which objective was building a GIS tool to develop two counties north the province of Almeria, it was required to build an topologic model of the territory to evaluate proposals to stop the erosion of the area and manage hydrological risks. In our case, we decided to use the TopoShape utility included into Idrisi, which offered the required functionality (generating an adequate topologic classification of the territory). After applying the option to the work digital elevation model of the territory, we obtained a dismaying result; the image was a confusing mix of minimal topologic structures. From the bibliography, we got the idea of a) changing input configuration parameters and b) preprocessing the image using the FFT; obtaining a better result from the second option. However, we decided to analyze the reason of the observed behavior, and look for a possible use of this feature. Based in the origin of the observed behavior, the great detail of the used DEM, we built a set of treatment alternatives in order to exploit the detailed data. From this set of treatments we could establish a qualitative correlation between the changing of topologic structures and the erosion of the territory. We propose a set of alternative topologic treatments, which results are compared.