Institute of Tropical Meteorology, Poona-5.
Mean monthly and annual basin rainfall up to Bhimkund Dam site in the Orissa State has been worked out by the isohyetal method on the basis of 1950 rainfall normals. Maximum probable storm for the proposed Bhimkund Bam has been worked out by depth-duration and depth-area-duration methods. It is seen that within broad limits of ± 1 to 3 per cent, maximum 2 and 3-day rainfall depths by these two methods correspond to rain depths of 1000-year return period for the same durations. These depths of rainfall have been maximized by moisture charge method to obtain maximum probable depths of rainfall for the basin. The distribution of maximum 2-day design rainfall for estimating design flood hydrograph has been worked out on the basis of hourly distribution of Bhimkund recording rainspell data. The point rainfall distribution thus obtained, has further been adjusted for the basin area taking into consideration the studies available on this subject in this country.
