Flood frequency analysis and susceptibility zonation of the Haora River Basin, Northeast India

Flooding remains one of the most destructive natural disasters, posing significant risks to both human lives and infrastructure. In India, where a large area is susceptible to flood hazards, the importance of accurate flood frequency analysis (FFA) and flood susceptibility mapping cannot be overstated. This study focuses on the Haora River basin in Tripura, a region prone to frequent flooding due to a combination of natural and anthropogenic factors. This study evaluates the suitability of the Log-Pearson Type III (LP-III) and Gumbel Extreme Value-1 (EV-1) distributions for estimating peak discharges and delineates flood-susceptible zones in the Haora River basin, Tripura. Using 40 years of peak discharge data (1984–2023), the LP-III distribution was identified as the most appropriate model based on goodness-of-fit tests. Flood susceptibility mapping, integrating 16 thematic layers through the Analytical Hierarchy Process, identified 8%, 64%, and 26% of the area as high, moderate, and low susceptibility zones, respectively, with a model success rate of 0.81. The findings highlight the need for improved flood management strategies, such as enhancing river capacity and constructing flood spill channels. These insights are critical for designing targeted flood mitigation measures in the Haora basin and other flood-prone regions. © 2025 The Author(s). River published by Wiley-VCH GmbH on behalf of China Institute of Water Resources and Hydropower Research (IWHR).