Impact of Sand Excavation in the Pearl River System on Hydrology and Environment

The river system of Pearl River Delta in China is a typical tidal network and is affected by both the surface runoff and the tide of South Sea. In the 80s of last century, with the speed-up of economy development and urbanization, sand excavation in this district was started. This has led to the great changes of the hydrological conditions and the river fluvial process. According to its hydrodynamics features, this paper builds a one-dimensional hydrodynamics mathematical model to simulate the changes of water level and flow rate. Besides, according to the riverbed evolvement in future years caused by sand excavation, the paper respectively forecasts the changes of water level and flow ratio in high flow and low water periods. Further, the impacts of sand excavation on navigation, irrigation, salt intrusion and water environment are simply assessed.