Automated extraction of drainage network and watershed boundary from ASTER DEM and SRTM DEM and comparison with Topomap - A case study

Abstract

For proper planning and management of water resources the adequate delimitation of watershed and its drainage is highly essential. This work deals with the evaluation of drainage network extracted automatically from Digital Elevation Models (DEM) obtained from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Shuttle Radar Topography Mission (SRTM) and watershed delineation. The comparison of drainage characteristics derived from satellite data with the topomap were analyzed. Bharathapuzha River basin is spreading its drainage network in Kerala and Tamilnadu. Arc Hydro tools (version 2.0) an application extension for Arc GIS 10 recently released by ESRI was used to extract drainage network. The threshold value for deciding on the required drainage density is arrived at by trial and error method where the watershed boundary derived from digital network matches the digitized boundary most accurately. The comparison of drainage network derived from ASTER and SRTM with the drainage from topomap is based on the stream length aspect. The length of the drainage network derived from the DEMs has a better resemblance with the topomap. 2013 CAFET-INNOVA TECHNICAL SOCIETY.