Role of moisture transport in extreme flood events in the Brahmaputra basin

Abstract

The Brahmaputra River basin, a complex hydrological system in South Asia, is among the most flood-prone regions in the world. It frequently experiences severe and devastating flood events. The floods are closely linked to the region’s complex atmospheric moisture dynamics, which govern the spatiotemporal distribution of precipitation. However, the mechanisms driving extreme precipitation events, especially their connection to large-scale moisture transport, remain poorly understood. We investigate the role of Integrated Vapor Transport (IVT) in the initiation and intensification of extreme flood events within the Brahmaputra basin. We analyzed the spatial and temporal patterns of IVT and their correlation with changes in patterns of precipitation. Our findings indicate that IVT, characterized by strong moisture flux convergence, is closely associated with significant increases in rainfall intensity, particularly during the summer monsoon season. The improved understanding of the physical mechanisms behind precipitation intensification can significantly improve forecasting and early warning systems for extreme flood events. These advancements are crucial for mitigating the impacts of extreme floods and enhancing the actionable strategies in one of the world’s most vulnerable regions.