Research Of The Pearl River Delta's Water Condition And Water Environment Influence By Sand Excavation

The Pearl River Delta next to the South Sea of China is highly developed in economy and culture and plays a very important role for the development of China's economy. The river system is a typical tidal network. Its hydrological condition is affected by both local surface runoff and tide level of South Sea. Since the 80s of last century, with economy and urbanization speeding up, large-scale sand excavation in this district was started and it's been expending in recent years. This has lead to great changes of riverbed evolvement and hydrological conditions. Based on the hydraulic features of river network, this paper builds the one-dimension network hydraulic mathematical model to simulate the spatial-temporal changes of water level and flow rate. The model is calibrated and validated by the observed water level and flow ratio of the river system. Further, according to the riverbed evolvement in future years forecasted by the Grey Model under the condition of sand excavation, the paper respectively forecasts the changes of water level and flow in the two representative hydrological conditions of high water and low water periods. Finally, the impact of sand excavation on navigation, irrigation, salt intrusion and water environment are generally assessed.