人工采砂对东江干流局部河段河床冲淤的影响研究

Study on the effect of sand excavation on the local riverbed variation in the Dongjiang River

基于水动力学方法、泥沙输移原理,建立了一维河流河床冲淤数学模型,并应用于东江干流岭下站～博罗站河段河床冲淤变化分析和预测研究。根据1972-1999年历史地形、水文、采砂资料进行河床冲淤变化分析,在1972-1999年期间,河床整体呈下切状态,人工采砂对河床冲淤变化有重大影响。在此基础上预测未来10年-20年河床冲淤变化状况,如果不考虑人工采砂影响,河床整体以淤积为主,下游河床淤积更明显,如果考虑人工采砂影响,河床则整体呈下切状态。这一研究结果表明:人工采砂直接影响研究河段河床冲淤变化形态,对河道通航和引水工程等都有很大的影响。同时,该研究结果也可为建立合理的采砂制度和建设有效的工程措施提供依据。

Based on the theory of hydrodynamics and sediment transport,a one-dimensional mathematic model for riverbed variation is developed.The model is applied to the Lingxia-Boluo section of Dongjiang River to simulate the riverbed variation.The measured data of river terrain,hydrology,and sand-excavating from 1972 to 1999 are used.The result shows that riverbed is in erosion status over the last twenty years.The riverbed variation in future 10-20 years is also simulated,and the result shows that if sand-excavating continues,the riverbed will be eroded continuously,otherwise it will be deposited in most of the research section,especially in the lower reaches.It suggests that the sand-excavating has great influence on riverbed terrain,navigation, water intake,etc.The research results provide a theoretical support for the exploiting plan and hydro-project construction.