Flood Simulation of Urbanizing Watershed by Coupling Land Use/Cover Changes with Distributed Hydrological Model: A Case Study of Buji River in Southern China

Land use/cover (LUC) has changed largely due to urbanization that has been well observed worldwide in recent decades, which impacts the hydrological process, particularly increasing the peak flow and runoff coefficient. To simulate/forecast the flood process in the urbanizing watersheds effectively, the LUC changes need to be incorporated into the flood simulation/forecast hydrological model to reflect this change. In this study, the latest LUC of the urbanizing watershed that is derived from the remote sensing images, is coupled with a distributed hydrological model for watershed flood process simulation. The distributed hydrological model employed is the Liuxihe model, a physically based distributed watershed hydrological model mainly proposed for flood forecasting. In the model, the vegetation type parameters are highly related to the LUC types, so the model parameters could be changed according to the LUC changes, and a more realistic flood simulation result could be achieved. In this study, an urbanizing watershed in southern China has been case studied.