Evaluation of geomorphological parameters of selected watersheds from tapi basin using GIS

In this study twelve geomorphological parameters of ten watersheds of Tapi basin were evaluated using Geographical Information System (GIS). The selected geomorphological parameters were average slope of the watershed (Sa), elongation ratio (Re), circulatory ratio (Rc), basin shape factor (Sb), relief ratio(Rf), relative relief (Rr), ruggedness number (R_N), main stream channel slope (Sc), drainage factor (Df), stream length ratio (Rl), bifurcation ratio (Rb), and length width ratio (Lbw). Toposheets of the study area were obtained from the Survey of India (SOI), Dehradun and Geological Survey of India, Pune regional office in the 1: 250000 and 1: 50000 scale. These toposheets were used for digitization and georeferencing with the help of ArcGIS 9.3 software for evaluation of the parameters. These parameters can be used for development of geomorphological models to study various hydrological processes.