Application of Satellite Radar Altimeter Data in Operational Flood Forecasting of Bangladesh

This study demonstrates the applicability of satellite-based radar altimeter flood forecasting in downstream flood prone areas of Bangladesh without the use of data assimilation. The joint NASA-French satellite mission JASON-2 provides water level elevation data over the Ganges-Brahmaputra-Meghna (GBM) basin at no cost to end users. A nearly linear relationship was established between these upstream water elevation observations with the downstream water levels in Bangladesh especially in the Ganges and Brahmaputra basins. Using this remotely sensed data as boundary inflow in the current flood forecasting model developed by the Flood Forecasting and Warning Center (FFWC; see FFWC 2014) within the Bangladesh Water Development Board (BWDB), it is possible to generate a 5 day or more flood forecast in some downstream locations with considerable accuracy. This approach was validated using remotely sensed JASON-2 observations from 2014 and comparing the resulting flood forecast with recorded ground measurements of river height. This study highlights the potential of using JASON-2 data for flood forecasting on international rivers like in Bangladesh where upstream hydrologic observations are otherwise unavailable.