Study On River Shoal Evolution Based On Modern Technique

Studying on river shoal evolution is a fundamental work in the science of water conservancy, water conservancy projects and waterways planning, designing, management and engineering feasibility. In this paper, river shoal evolution is studied by means of modern science and technique, combined with the real projects. Particular contents are presented as follow.In Part I , the mathematical model between remote sensing image spectral value and survey water-depth is built in Zhuqi-Houguan of Minjiang river by remote sensing (RS). It is proved that the error caused by mixing water-land information on boundary may be eliminated by choosing the research waters within the water boundary under designed lowest navigable stage, and the precision of remote water-depth of river may be enhanced.In Part II, the theory of artificial neural network (ANN) is introduced briefly, the principle of back propagation(BP) neural network is analyzed. River shoal evolution prediction models on a BP neural network are established on analyzing factors affecting shoal evolution in a river, and input as well as output factors are determined by analyzing, the methods of obtaining these factors and selecting training samples are presented, and the designing of a BP network is also studied. The predicted result showed good agreement with field data in Zhouqi-Houguan of Minjiang river.In Part III, the significance, problem and methods of integrating plane 2-D sediment mathematical model with geographical information system (GIS) are discussed . The mathematical model based on GIS is built, and the interface program of data conversion between the two models is designed, and the spatial discretion of the computational domain is discussed. The model is used to predict the influence of regulation work on shoal evolution in Zhouqi-Houguan of Minjiang river, and the results are adopted by the department of responsibility conservancy.In Part IV, the system of simulating and predicting is developed by mean of a Visual Basic and GIS ,according to the two shoal evolution prediction models in Zhouqi-Houguan of Minjiang river. The general framework is designed, the schemes of some critical techniques of the platform such as data interface and model-creating techniques are presented, then the main functions and platform are outlined.The work in this paper is concerned with the theoretical method, combined with the projects of regulation work of waterway and management information system in Zhouqi-Houguan of Minjiang river. Efforts have been made to explore new route of studying shoal evolution in water conservancy discipline, it is expect to have a bright future in practical application.