Flood Frequency Analysis Using Gumbel’s Distribution Method and Log-Pearson Type III Distribution Method in Krishna River, Andhra Pradesh

Abstract

AbstractExtreme rainfall events and the resulting floods can take thousands of lives and cause billions of rupees in damage. Assessment of Flood peak water levels in rivers is required for the design of hydraulic structures across the river by the decision-makers. Frequency analysis is based on fitting a probability distribution to a series of observations to estimate the future probabilities of occurrence of many events of interest. In this research work, Gumbel’s distribution method and log-Pearson type (LPT) III distribution used for the finding of peak flows for different return periods in the Krishna river in Andhra Pradesh. 37 years (1980–2016) annual peak discharge data used for the analysis at Wadenepally river point in Krishna River. Frequency analysis of flood peak is done for the different return periods of 10, 25, 50, 100, and 200 years in the Study area. Results reveal that Study area is better adopted for Gumbel’s Extreme value distribution, even though the log-Pearson type (LPT) III distribution estimates higher values compared to the Gumbel’s distribution for the high return period.KeywordsFloodFrequency analysisGumbel’s distribution methodLog-Pearson type (LPT) III distribution method