Study On Water And Salt Balance Model In Bostan Lake Basin

In the past 50 years, with the economic development of Bayinguolen Mongolian Autonomous Prefecture, it brought a series of ecological environment problems in Bostan Lake Basin, such as soil salinization, water-quality deterioration, and lakeside wetland degradation, and so on. In order to improve and protect the basin's environment of water and soil resources, it is awfully necessitated to construct a water and salt balance model which can be applicable to the basin. We hope that it can be easer to find the moisture and salt movement mode by the model. And then we can analyse and estimate its condition of water and soil resources, and realize the sustainable utilization of water and soil resources, and improve the ecological environment.The thesis summarizes the basic situation of bostan lake basin and analyses the origin cause of formation of its environmental change firstly. Then, based on the Tarim Basin Water and Salt Balance Model which was developed by J.J.van Wonderen, it mainly study on the water balance and complement the salt balance research. At the same time, it modifies furtherly the Runoff-evaporation Hydrological Model for Arid Oasis which was constructed by three universities represented by Tsinghua University. And then, the corresponding software named Water and Salt Balance Model in Bostan Lake Basin (BostanWSBM for short) was developed. Finally, with the help of the BostanWSBM, the current situation of water and salt balance in Bostan Lake Basin was simulated and analysed. And, according to four projects drawed out by taking into consideration some engineering projects which will be operated recently in the basin, water and salt balance of different projects was simulated. And then, it predicts and analyses the environmental change under different projects of the basin. And the main achievements in the thesis are as follows:(1) It illustrates briefly the basic principle of BostanWSBM and makes the method in the rates of some parameters. It is emphasis on study on the relation of water and salt balance of Dahu and Xiaohu of Bostan Lake.(2) With three major application softwares as tools, which are Compaq Visual Fortran 6.5 and Microsoft Office Excel 2003 and Visual Basic 6.0, it finishs separately three major functions which are the core module of model calculation, database administration and user' interface controlling. And then, the sofrware package of BostanWSBM is developed.(3) According to those results of water and salt balance simulated by BostanWSBM under the current condition, the main analyses are as follows: First, the water utilization mode in irrigation area is extensive and the water consumption of field crops is heavy. Secondly, because of the poor management level on the canals, it leads to a terrible waste of water resources about half of which lost midway. Thirdly, the water level of Bostan Lake is stabled basically between 1,045m and 1,047m, belongs to the normal phenomenon. Finally, annual average water-salt is basically in the status of balance in Yanji Basin. Annual average desalination is 540,000t in Bostan Lake. Annual average salination 780,000t in Peacock River Basin, which mainly is concentrated in the drainage dissolving and discharging areas, and "wasteland" which are intercalated in irrigation areas.(4) Using BostanWSBM to predict and analyse four projects, it shows that the application of BostanWSBM has better effect.