Bihar's Battle Against Flood: Unravelling the Science of Flood Forecasting and the Primacy of Multi-Source Data Integration

Abstract

The state of Bihar in India is often vulnerable to catastrophic floods during the monsoon season due to its vast alluvial plains and the systematic pattern of transboundary Himalayan Rivers Systems that flow through it, with their origins in the Himalayas. These floods result in the loss of lives, livelihoods, and infrastructure, among other effects, leading to socio-economic losses that affect millions of people. As such, efficient flood prediction and early warning mechanisms are not just a technical wish; there is an urgent need to incorporate flood prediction and early warning systems into disaster risk reduction and climate change adaptation in the region. This article provides a detailed examination of the flood forecasting paradigm in Bihar, particularly its evolution over the years, from traditional empirical forecasting techniques to more advanced hydrological and hydrodynamic models based on data. It cuts across the institutional structure headed by agencies such as the Central Water Commission (CWC) and the Bihar State Disaster Management Authority (BSDMA), which are responsible for making predictions and distributing them. One of the main points of this study is the importance of data in present-day forecasting, which is the lifeblood of the modern era. We examine the complex procedure of incorporating multi-source information streams, including ground-based data, satellite-derived rainfall information, real-time river gauge and discharge data, high-resolution topographical data, and essential transboundary hydrological data provided by Nepal.