3-An alternative statistical regional approach for estimating design flood peak.

Abstract

Regional flood frequency studies are often made following traditional approach viz, a formula for mean annual flood and growth factors for higher return periods based on individual station values. This approach necessitates data generation and individual station studies introduce jerks in growth factor values. The pooled regional growth curve approach provides better prediction values and permits utilisation of all available data from different stations. The values of Q/Q and Y of all samples computed, grouped, averaged and then a combined growth curve for the region is obtained. This method is illustrated with details of studies and results for Mahanadi river basin (Subzone 3 'd'). Annual peak flood data of 16 sites (16 to 28 years) are considered and the efficacy of the pooled curve is tested.