Co-development of a Flash Flood Forecasting System for the Transboundary Meghna Basin: A Collaborative Approach

Topography and periodic monsoon rainfall makes the Northeast region of Bangladesh one of the most flood-prone areas in the world. In addition to impacting the lives and livelihoods of people, floods also have a significant impact on the economy of the country. Therefore, given the significant impact of floods, Flood Early Warning Systems (FEWS) are crucial for providing timely flood information. International Centre for Integrated Mountain Development (ICIMOD) in collaboration with the Flood Forecasting and Warning Center (FFWC) has developed a flash flood forecasting model using open-source resources. This paper describes the process involved in developing the model using SERVIR’s Service Planning Approach. This framework ensures that stakeholders and end users are incorporated in all levels of planning and system development. The model uses the High-Impact Weather Assessment Toolkit’s (HIWAT) precipitation forecast as a forcing into a hydrological model to generate hourly flood information up to 2 days in advance. The model was calibrated and validated using discharge data at various locations. The evaluation of the model indicates that the system was able to capture the historical discharge with good agreement. Detailed training was also provided to the staff of FFWC, so they are aware of the functionality of the system. This system is expected to provide better flash flood forecasting due to increased resolution compared to the current system at the FFWC.