5-Chapter-V-Design flood studies

Abstract

For the estimation of design flood for any water resources project, the hydrologist often needs to have a fairly reliable es1 1 a of design storm. Among the various methods used for the estimation of design storm the commonly used methods are :

(i ) Depth-duration (DD) analysis (ii ) Depth-area'duration (DAD) analysis (iii ) Storm transposition

The depths obtained by any one of these methods are maximised for moisture content to obtain the probable maximum precipitation (PMP) estir ,s. Subsequently the PMP values are distributed into shorter t intervals and arranged in order to get design sequence the storm at shorter time intervals. This lecture describeS the physical methods of estimation of design storm alongwith moisture maximisation for estimating the probable maximum precipitation (PMP). Further the technique of distribution of the PMP into shorter intervals would also described.