Extreme Contrariety in Northeastern Bangladesh: Causes, Effects, and Remedial Measures for Flash Floods and Drought Flows

Flash floods are a widespread phenomenon in north-eastern Bangladesh. However, the 2022 flood scenario was different compared to past scenarios. Three consecutive floods in 2022, 2023, and 2024 are unprecedented. Among these, the flash flood of 2022 was the most destructive. A field survey and land cover analysis were conducted to investigate the causes of the unusual flooding and assess the Barak-Surma-Kushiyara River basin and its tributaries. The study found that the main reasons for the long-lasting flood were a mix of natural and human activities, including heavy rainfall, low navigability, narrow rivers and canals, land grabs, riverbank erosion, unplanned urbanisation, and construction in haors (bowl-shaped natural depressions), etc. The research team found the river almost dead from the Amalsid point of the Surma River to the Lovachhra estuary. As a result, the navigability of the entire river has decreased, which causes the river basin to flood almost every year. The team strongly suggests implementing capital dredging in the Surma-Kushiyara to ensure the consistent flow of international rivers. Conducting a high-level conference with neighbouring countries poses a significant challenge in reducing the risk of future floods. The government of Bangladesh should prepare a long-term plan to ensure the normal condition of the rivers in northeastern Bangladesh, to avert a possible major disaster in the future. Bilateral agreements for transboundary river management and AI, IoT, and big data for early flood prediction are also suggested in this study. Long-term planning and sophisticated monitoring are needed to protect livelihoods from floods.