Application of NRCS Model to Watershed Having No Landcover Data

Abstract

In the present study NRCS model is applied with a velocity factor estimation technique that relies on length and slope characteristics of a watershed. As given by Kirpich formula and velocity relationship characteristics flow velocity for a watershed can be estimated directly by using length and slope values. Suitability of the estimation technique was tested earlier with satisfactory results. The model is applied to derive 1-hr UH for Madhura and Ghagra watersheds located in Barak basin in India. Drainage network for the watersheds and the geomorphologic parameters are estimated using 30m-ASTER DEM. Length and average slope values for the watersheds are estimated using GIS technique. Peak UH characteristics results obtained applying the model is compared with earlier GIUH results, comparison of the results show that NRCS model when used with velocity factor estimated on the basis of length and slope characteristics give similar results. Incorporation of new velocity parameter estimation technique allows applying NRCS model to watersheds having no landcover data making it more useful for ungauged watersheds.