ESTIMATION OF PROBABLE MAXIMUM PRECIPITATION FOR CATCHMENTS IN EASTERN INDIA BY A GENERALIZED-METHOD

A generalized method to estimate the probable maximum precipitation (P MP) has been developed for catchments in eastern India (80 degrees E, 18 degrees N) by pooling together all the major rainstorms that have o ccurred in this area. The areal raindepths of these storms are normali zed for factors such as storm dew point temperature, distance of the s torm from the coast, topographic effects and any intervening mountain barriers between the storm area and the moisture source. The normalize d values are then applied, with appropriate adjustment factors in esti mating PMP raindepths, to the Subarnarekha river catchment (upto the C handil dam site) with an area of 5663 km(2). The PMP rainfall for 1,2 and 3 days were found to be roughly 53 cm, 78 cm and 98 cm, respective ly. It is expected that the application of the generalized method prop osed here will give more reliable estimates of PMP for different durat ion rainfall events.