Metodologia semiautomatica di estrazione del drenaggio da DTM applicata allo studio della deformazione indotta da tettonica attiva

Abstract

The statistical analysis of stream orientations is an helpful tool in the active tectonic studies because the rivers network is an important geomorphologic feature useful to derive the deformation due to active faults. The drainage network automatically derived from DTM’s is not generally usable for this type of analysis because the automatic routines generate the stream network following the four direction orthogonal to the cell. In this paper we present a semiautomatic methodology to extract the drainage network from high resolution DTM data (5x5 pixel m) the most possible consistent with the real water-drainage pattern, in order to make accurate statistic azimuthal analyses of stream orientations. The methodology have been tested on the active tectonic area of the Tammaro basin (Campania and Molise Regions), epicentral zone of the 1688 strong earthquake (MW=6.7). The results obtained by the application of the proposed methodology show a good agreement with the drainage pattern map derived from photo-interpretation (Regional Technical Cartography).