Comparative Analysis of Manual and GIS-Based Watershed Delineation Techniques Using DEMs

Effective watershed management is essential for sustainable water resource planning and ecological conservation. This study examines the Cooum Watershed in Tamil Nadu, India, comparing manual delineation methods with GIS-based approaches using Digital Elevation Models (DEMs) from ASTER and GM-TED. It analyzes river network changes between 1999 and 2010, validating GIS data with GPS inputs to assess the accuracy of automated delineation techniques. The findings highlight GIS's effectiveness in stream network extraction while addressing limitations like georeferencing errors.