Research On Water Resource Utilization Planning And Desertification Control And Prevention Technology Of Oasis In Dulan

Oasis is a geographical and ecological area with stable water source for desert plants' growing well or human reproduction. This shows that water is a major constraint in arid area, it's the lifeblood of the oasis. Many oasis environmental problems are due to human activities, directly or indirectly caused by changes in the balance of water, such as salinization of cultivated land or oasis desertification. And rational utilization of water resources can improve soil structure, increase grain yield, improve the ecological environment both inside and outside the oasis, expand the oasis area and combat desertification.Considering of above reasons, this paper have taken a systematical research on status of water resources, water supply and demand balance, water resources development and utilization planning, and comprehensive anti-desertification technologies under the basic principles of sustainable development. We had made overall arrangements on water resources assessment, planning, development, utilization and management to ensure that the utilization of water resource is under the capacity of environment. Then we proposed the oasis technical system of desertification control by summing up experience of desertification control and relevant experimental studies in Qaidam Basin, and using NDVI to evaluate the effect of desertification. The conclusions are as follows:(1)Tsagan Us oasis river system includes Tsagan Us River and Xiariha River. The annual average runoff volume is 197.53 million m3, the amount of ground water is 197.94 million m3, and the total amount of water resource is 252.55 million m3. The water testing shows that the quality of river surface water and ground water are good.(2)With the year of 2005 as the actuality year,2015 and 2030 as the planning year, the development and utilization plan was proposed. Integrated water resource supply and demand balance analysis, we plan to improve 10600 hm2 irrigation land and fulfill the construction of Qiwa reservoir before 2015 to meet the basic water use. And build Xiariha reservoir as a regulate reservoir in drought season. Also three small hydropower stations will be built.(3)The oasis technical system of desertification control includes technical system of engineering control and vegetation construction. Technique of chemical materials sand fixation and mechanical sand barrier constitute engineering control system. Oasis shelter forest, technique of sand fixing afforestation and fencing recovery constitue vegetation construction system. (4)By using NDVI method to evaluate the effect of desertification control in Tsagan Us oasis, the results of evaluation showed that in the last decade, vegetation coverage in the region indicates an increasing tend. Increasing area includes grade 3(30%-60% coverage) and grade 4(60%-100% coverage), while decresing area area include grade 1(0%-10%). It means that desertification in the region has been effectively governed, vegetation coverage had changed from low to higher levels. After more than 10 years comprehensive management of the region, the area of desertification had been significantly reduced.