Methodologies for identification of drainage structures: space filling vs. hydrodynamics

The concept of slope scaling with contributing area proposed by LaA Barbera and Roth [this volume] is used as an indicator of channel initiation and for channel maintenance. This concept is shown to be a useful criterion for the identification of the effective drainage structure of the basin; existing Digital Terrain Models (DEMs) are used for the purpose. Integral properties of the single DEM pixel are introduced in order to reduce the noise due to a possible DEM low accuracy, e.g. in the estimation of the local slope value from the elevation data set. The resulting network is characterized by a non unifonn drainage density.