塔里木盆地水资源永续利用的环境学模型分析

从环境学的角度出发,结合塔里木盆地水资源分布及特征,阐述了水资源永续利用的基本概念模式及演变控制的生态风险评价,并运用环境学模型分析探讨了该地区水资源利用现状中存在的问题及永续利用的可行性,初步建构了中国西北地区水资源永续利用的理论和实践框架.

ENVIRONMENTOLOGICAL MODEL ANALYSIS FOR SUSTAINABLE UTILIZATION OF WATER RESOURCES IN TARIM BASIN

Tarim Basin is located between two tectonically active zones of the Tianshan Mountains and the Kunlun Mountains. The alternations of the mountains and basin shaped the distribution pattern of the regional water resources. The Tarim Basin is the largest inland basin in China and is also a typical fragile environmental system in the northwestern China. Water resources are crucial in maintaining the oasis ecosystem for a sustainable development. In Tarim Basin, precipitation and meltwater are major sources of the surface water. Groundwater is mainly fed by precipitation, laterally discharged water and occlusion water. Evaporation is the main passway for water loss. Surface water and groundwater can transform mutually in different localities. Spatially, the water resources are unevenly distributed; greater portions are found in the north and west and smaller in the south and east. Runoff through rivers is concentrated in summer. In this paper, an environmentological model analysis and ecological risk assessment have been attempted based on the distribution and characteristics of the water resources in Tarim Basin. Through mathematical models for evolution control and risk decision, we evaluate the utilization of water resources in Tarim Basin for a sustainable development of the region. Currently, the total amount of the required water resources in Tarim Basin is 333.71 × 108 m3. The maximal continuable exploitation calculated by Model 1 is 304.13 × 108m3, and the total deficit is 29.58 × 108m3. To reach a sustainable goal, therefore, an integrate planning should be made and practised. In the risk decision models of water resources management the risk index of water resources utilization R is 0.346 and the reliability index a is 0.654, showing that the risk coefficient of water resources is remarkably higher. The main reason is the long-term over-use of surface water that causes intensive evapotranspiration loss and the change in the complementary transform mechanism between surface water and underground water.Furthermore, the holistic loss index β is 0.207, equivalent to a loss rate of 20.7% caused by aridity. This is likely related to seasonal variations of water resources in Tarim Basin, as was observed, droughts in spring, flood in summer, water shortage in autumn and dry in winter. The restoration index of water resources y is 0.713, implying that some drought Periods may last for long and regional ecological environment could be severely unbalanced. High efficiency of water use in industry and agriculture is a better way to reduce the water resources risk. The application of evolvement controlling model concerning water resources of ecology-economics complex system can be used to determine the stability of internal structure and evolutive orientation of the whole system. We hope that this study could serve as a theoretical frame for a sustainable utilization of water resources in the northwestern China.