Flood Frequency Analysis of Lower Krishna Basin using Gumbel Method at Prakasam Barrage, Vijayawada, Andhra Pradesh

Abstract

The Gumbel Distribution approach is used in this study for analyzing the flood frequency in the lower Krishna basin. It is a probability distribution method that was used to predict river annual peak discharges from 2007 through 2021 (14 years). The probability distribution function was used to calculate the return period for 2, 5, 10, 15 and 20 years and estimated discharges were produced. The flood for the next 10 years will be 1239523 Cusecs and the predicted flood discharge for the next 25 years will be 1586634 Cusecs. The expected flood from 2 to 25 years has also indicated a consistent growing tendency in selected Prakasam barrage station. This type of information would be useful in the planning of engineering projects such as reservoirs, bridges, flood mitigation structures etc. Flood hazard maps can also be created using these methodologies.