ANALYSIS OF UNIT HYDROGRAPHS FROM UTTAR PRADESH

Abstract

Based on data from catchments in the U.S.A., S der, Commons, S,C.S, and Mitchell have developed methods correlating catchment characteristics with the unit hydro.. graph elements such -as time lag, period of rise, peak flow and time base, hese methods can be used to construct unit hydrographs for ung,auged catchmefts. !Jhe rainfall, runoff data from U.P. catchments located in H3malyan range and in eastern U.?. have been used to check the applicability of these methods to Indian catchments. It has been found that none of the methods gives consistently good results. The argument that regional values, in place of constants given by various investigators, will yield better results is subs tan ti ated+ Dimensionless graphs using United States Sail Conservation Service method have been prepared for each catchment under study. The shape of unit hydrograph is retained in all the cases. If these graphs are used after period of rise and peak flow have been ascertained using appropriate correlations for known values of topographic characteristics, these will describe actual unit graphs, to a high degree of accuracy,,, Dimensionless graphs as suggested by Gray have been constructed to facilitate the development of unit h 9drograph and distribution graph for ungauged catchments.