Effects of the impounding process during the flood season on algal blooms in Xiangxi Bay in the Three Gorges Reservoir, China

•A hydrodynamic and water quality model was developed for Xiangxi Bay in the Three Gorges Reservoir.•The model was calibrated for flow field, water temperature, and chlorophyll-a.•The stronger water temperature stratification was, the greater chlorophyll-a concentration would be.•Density currents could control algal blooms by weakening water temperature stratification.•Ecological reservoir operation for algae control was recommended.