Establishment Of Yongjiang River Water Pollution Forecasting System Based On Gis

It is an effective means for environmental management to establish the water quality forecasting system to predictive the water quality, simulate the water pollution, and make the decision on the environmental issues, in region water environmental administration. For the sake of water security of Nanning, the water pollution system of Yongjiang River based on the secondary development of GIS was established in the develop environment of C#.net to provide technical support for making decision on water pollution problems by water quality forecasting results visualization and improving the capacity of water quality forecasting and early-warning. The paper mainly consists of following several aspects:Based on the requirement of water environmental management and the characteristics of GIS, the water pollution forecasting system of Yongjiang River based on GIS has been designed from the structure, function and so on.Based on the characteristics of GIS and the features of the water quality models, the system technological routs has been devised after comparing some secondary development soft ware of GIS. Database as basis, using the key technologies, for instance, component technology and the Plug-in technology, the river spatial discretiziation was realized first, and then the GIS and water quality models were integrated, finally, the system was establish by C#.NET.The system realized mainstream fixed source pollution forecast, accidental pollution forecast and inland fixed source pollution forecast. The diffusion process of pollutants was simulated, and the color rendering of different levels were corresponded to concentrations of pollutants in different points, which make the department of environmental administration master the pollution of each of the river. Mainstream fixed source pollution forecast, it provided not only the pollutant concentration level display map but also the water quality grates distinguishing map after the forecast results were compared with the surface water quality standard. Mainstream accidental pollution forecast, it realized dynamic demonstration for forecast results, which makes the department of environmental administration master the space-time information of the accidental water pollution easily.