Development of Regional Flood Frequency Relationships using L-Moments for Lower Narmada and Tapi Subzone 3(b)

摘要

For planning, development and sustainable management of water resources, applications of advance methodologies are essential for prediction of magnitudes of likely occurrence of floods. The L-moments are a recent development within statistics and offer significant advantages over ordinary product moments. Regional flood frequency analysis has been performed using the L-moments approach. Screening of the annual maximum peak flood data has been conducted employing the L-moments based discordancy measure (Di) and homogeneity of a region has is tested using the heterogeneity measure W. Based on the L-moments ratio diagram and |Z{sup}(dist)| Pstatistic criteria, Generalized normal distribution (GNO) has been identified as the robust distribution for the study area. Regional flood frequency relationship has been developed for gauged catchments of the study area, using the robust identified frequency distribution. For estimation of floods of various return periods for ungauged catchments, a regional relationship Between mean annual peak food and catchment area has developed and the same is coupled with the regional food frequency relationship developed for the gauged catchments.