Hydrology Journal

In water resources planning and management many problems are faced in estimation of flood flows in ungauged catchments. Researchers have been adopting different techniques in estimating flows from ungauged catchments for design and risk analysis of hydraulic structures. The important aspect in such situations is an assessment of Peak Maximum Rainfall (PMR). This PMR is derived through statistical methods. The PMR for big catchments is estimated using scientific tools and is widely known as Probable Maximum Precipitation (PMP). The paper presents one such case study of Lakya catchment in Bhadra head water reach for which the peak flood has been estimated with the extreme precipitation derived. Extreme Value Type-1 probability distribution was selected for PMR estimation. Various methods exist for determining the parameter estimates of probability distribution from a given sample of daily maximum rainfall. In this paper, the method of self-determined probability weighted moments (SD-PWM) is included as an alternative method for parameter estimation for extreme value distribution. In all, about seven methods including the SD-PWM for the extreme value estimation have been studied. To examine the relative performance of the SD-PWM estimations, parameters and extreme rainfalls were also estimated with MOM, MLM, PWM, L’ Mom., POME and MLE. The goodness of fit for the results obtained using SD-PWM has been determined.