Flood risk assessment for Indian sub-continental river basins

Abstract

Abstract. Floods are among India's most frequently occurring natural disasters, which disrupt all aspects of socio-economic well-being. A large population is affected by floods during almost every summer monsoon season in India, leaving its footprint through human mortality, migration, and damage to agriculture and infrastructure. Despite the massive imprints of floods, sub-basin level flood risk assessment is still in its infancy and needs to be improved. Using hydrological and hydrodynamical models, we reconstructed sub-basin level observed floods for the 1901–2020 period. Our modelling framework includes the influence of 51 major reservoirs that affect flow variability and flood inundation. Sub-basins in the Ganga and Brahmaputra River basins witnessed the greatest flood extent during the worst flood in the observational record. Major floods in the sub-basins of the Ganga and Brahmaputra occur during the late summer monsoon season (August–September). Beas, Brahmani, upper Satluj, Upper Godavari, Middle and Lower Krishna, and Vashishti sub-basins are among the most influenced by the dams, while Beas, Brahmani, Ravi, and Lower Satluj are among the most impacted by floods and the presence of dams. Bhagirathi, Gandak, Kosi, lower Brahmaputra, and Ghaghara are India's sub-basins with the highest flood risk. Our findings have implications for flood mitigation in India.

Micro‐spatial flood risk assessment in Nagaon district, Assam (India) using GIS‐based multi‐criteria decision analysis (MCDA) and analytical hierarchy process (AHP)

“…(2022), and Vegad et al. (2023) highlighted the significance of a number of factors in defining the nature and extent of flood risks. The FRZs of the Nagaon district are identified by the present research using seven significant physical and seven socioeconomic parameters.…”

“…(2022), and Vegad et al. (2023) in different parts of the world, however, studies on flood risks considering both the physical and socioeconomic attributes are still very limited in the northeastern part of India. Hazarika et al.…”

Enhanced Modulation of Streamflow Flash Droughts by Reservoir Operations in India

“…Model simulated streamflow with consideration of dams includes the influence of upstream reservoirs. Previous studies used the H08-CaMa-Flood combined model to simulate streamflow and investigate the influence of the reservoir on streamflow in Indian river basins (Boulange et al, 2021;Chuphal & Mishra, 2023aVegad et al, 2023).…”

“…After calibrating the model against daily streamflow, we evaluated the model performance against the observed daily live storage of 36 reservoirs (Table S2 (Chuphal & Mishra, 2023aVegad et al, 2023). In addition, Yamazaki et al (2011) evaluated the CaMa-Flood model against gauge observations and reproduced streamflow for 30 major river basins across the globe.…”