Research On Water Resources Characteristics And Its Rational Development Pattern For Arid Areas

Water resources are the indispensable material basis for human survival and its socioeconomic development. With the rapid development of economic society, on one hand, the imbalance between demand and supply are becoming critical due to increasing water demand. On the other hand, ecological environment has been damaged by human unreasonable water resources utilization. The Northwest arid of China is located in the hinterland of the Eurasian continent, with dry climate, scarce rainfall and strong evaporation; accordingly, water resources shortage in this area are serious very much. Because water resources are exploited irrationally for a long time, many serious ecological environmental issues have been occurred in some river basins, which limit the economic development of the Northwestern and the implementation of "Beautiful Mountains and Rivers Plan ", with negative impact on the improvement of people's living standards in northwestern arid areas. Therefore, it is necessary to analyse water resources of arid regions systematically, involving mastering its basic features and the relationship between typical valley water resource and the surrounding ecological environment; on a basis of that, it is to make scientific and rational water resources development pattern. As a result, the sustainable utilization of water resources can be realized finally.The doctoral dissertation interpreted the concept and distribution of arid, analysed the hydrological characteristics of groundwater and surface water in arid, and then concluded the formation, transformation as well as recharge and discharge rules of arid water resources. In this dissertation, Manas river basin was chosen to be a research area, which is a typical continental river basin located in arid. The dissertation studied the water resources features and situation of Manas river basin and its sustainable utilization problems. Based on the consideration of ecological water demand, the balance between demand and supply and water resources bearing capability are studied, coupled with water resources features and current utilization situation, the rational development pattern for this basin can be put up with, so as to provide theoretical fundation and data supporting for water resources sustainable development.The dissertation contains 9 chapters. Relied on a large number of literatures and researches done by other scientists, the first chapter concluded the arid concept and its distribution scope in the world and China, and obtained the basic features of hydrology in arid, including precipitation, evaporation, vegetation cover, ecological environment, etc. Meanwhile, this chapter also analysed the formation, recharge and discharge conditions and hydrological features of surface water and ground water in arid, explored the transformation relationship between surface water and groundwater of arid areas, and then studied the impacts of human activities on water resources and its surrounding environment in arid.Taking Manas river basin as a research area, which is a typical continental river basin located in arid, the second chapter analysed its hydrological characteristics of groundwater and surface water. Based on that, hydrological conception model and groundwater flow numerical model were built up making use of MODFLOW software to predict thegroundwater quantity and level for river basin plain areas. After comprehensive computation, the amount of river system ecological water demand of and oasis water demand are 4.9621×108m3 and 2.1124×108m3 respectively, and the total ecological water requirement amount is7.0745×108m3.In combination with current situation of river basin people economic and "eleven five" planning, the paper computed all sorts of water requirements in research area for the year of 2000, including livelihood, agriculture, industry, service industry and ecological environment, and made corresponding water demands amount prediction for the year of 2010 and 2020. In addition, coupled with surface water source (water coming frequencies are 75% and 50% respectively.) and groundwater source, the analysis was done for the balance between supply and demand. The results were shown as followings. In actuality year, water supply amount of surface water and groundwater are 19.5358x108m3 and 21.4458x108m3 respectively; water demand amount is 21.4311×108m3; water shortage amount is 1.8953×108m3, water surplus amount is 0.0147x108m3. In 2010, water supply amount of surface water and groundwater are 19.1409x10xm3 and 21.0509x108m3; water demand amount is 24.0762×108m3; water shortage amount are 4.9353 X 108m3 and 3.0253 X 108m3 respectively. In 2020, water supply amount of surface water and groundwater are 18.754×108m3and 20.664 X 108m3 respectively; water demand amount is 26.4336×108m3; water shortage amount are 7.6796×108m3 and 5.7696 X 108m3 respectively. All in all, with the rapid development of industry and agriculture, water shortage is becoming serious day by day.According to the utilization situation of river basin water resources,7 index are determined to evaluate water resources, including groundwater exploitation potentiality, surface water development potentiality, groundwater supply rate, surface water supply rate, groundwater quality, surface quality as well as surface regulation and storage capacity. By means of specifying the weights of the 7 index and fuzzy comprehensive evaluation matrix, the fuzzy comprehensive evaluation model was established to express river basin water resources development pattern. After the assessment of water resources development pattern, it can obtain rational and scientific developing pattern for irrigation districts in research area as following suggestions. Shihezi Irrigation District can use surface water as main water source with supplement of groundwater; Jin'an and Manas Irrigation Districts can make use of water resources in integration way of surface water and groundwater; Mosuowan and Xiaye Irrigation Districts can take groundwater as main water source with supplement of surface water. At last, compared with current situation, the paper indicates that6 the development pattern of above irrigation districts generated by fuzzy comprehensive evaluation model is rational and scientific, providing powerful foundation for water resources sustainability utilization of river basin.