Forecastmg storm ramfall over Bhagirathi catchment due to depressions/cyclonic storms

Abstract

Synoptic typing of systems contributing rainfall in catchment areas has been found to be a useful technique in quantitative precipitation forecasting. This paper contains detailed analysis of 68 rainstorm situations with one-day rainfall of 2.5 cm or more over the Bhagirathi catchment during the period 1901-1967 in association with depressions/cyclonic storms. An attempt has been made in this paper to: (i) Estimate the contribution of rainfall over the catchment vis-a-vis the location of the system. (ii) Estimate the intensities of the rainfall vis-à-vis the intensities of the causative system namely depressions / cyclonic storms.(iii)Determine the time  Determine the time interval between the origin of the system and its movement to an effective location to cause rainfall over the catchment; (iv) Make quick river assessment of average areal rainfall over the catchment on the basis of rainfall data from selected key stations, using regression equation and (v) Maximize the highest rainstorm of 26 September 1956 by moisture charge method.