SURFACE HYDROLOGIC APPRAISAL OF A NATURAL CATCHMENT

Abstract

Simple hydrological model such -as unit hydrograph is being used for making surface - hydrological appraisal from natural catchments. Several variations are available in literature for the same. The unit hydrograph method proposed by Clark (1945) is selected for use in present study for simulating direct runoff hydrograph for different discritized sub-watershed of Chambal river basin upstream of Gandhi Sagar dam. A geographic database for evaluation of catchment characteristics and discritization of bigger watershed into smaller sub-watershed is prepared. HEC-geoHMS interface is used to make geo-processing of the data. Clark model parameter for all eight discritized sub-catchment . have been calculated and related to measurable catchment characteristics. Result of the study indicate that the method of Clark is suitable for simulating peak, time to peak discharge as well as overall shape of the flood hydrograph. Developed relation for estimation of Clark model parameters exhibit R2 value between 0.97 and 0.99 indicating suitability of developed relations for estimation of Clark parameter for Chambal basin.