Valley lines extraction from DEM and its programming realization based on IDL&ArcGIS Engine

Extraction of valley lines from Digital Elevation Model (DEM) is a hot research spot in geological and hydrological field. Based on grid DEM, a valley lines extraction method was proposed and implemented by IDL&ArcGIS Engine mix programming. First the initial valley line extraction was implemented in IDL based on its morphological characteristics. Second the original valley line data was export into ArcGIS Engine, and combined with hydrological features, a further valley line extraction was made so as to generate the final valley line information. Finally a validation was proposed to export the valley line data into Google Earth to overlay with the image. The experiment result demonstrates the correctness of the algorithm.