The Predicted Demand of Water Resources in the Middle Reaches of the Heihe River from 1995 to 2050
XU Zhong-min, CHENG Guo-dong (Cold and Arid Regions Environmental and Engineering Reserch Institute, CAS, Lanzhou Gansu 730000, China)
From systematic point of view, this thesis features an empirical study of the demand of water resources in the Heihe River basin from 1995 to 2050. The demand of water resources usually increases owing to the growth of economy and the increasing of population. According to the specific situation of the Prefectures of Zhangye, Jiuquan and Jiayuguan in the middle reaches of the Heihe River, and the sophisticated economy structure, the macro-economy model and population model was introduced respectively. Water demand of ecology environment was specially dealed in the water resources demand model. Water demand of natural ecology and parts of artificial ecology such as forestry of protection canals and road are treated as exogenous variables. Other ecology such as natural grassland and artificial forestry was treated as exogenous variable, as subjects of resources in the economic model. In this paper, the systematic structure of macro-economy model was described in detail. Macro-economy model was established by adopting input-output methods. The key way of the macro-economy model is: fix asset inventory accounts for the production of aggregate output value; the aggregate production interprets gross dominant production; gross dominant production determines the amount of investment; and the amount of investment with the fix asset inventory decides the fix asset. Finally, the calculated results of the model shows that: water resources development and utilization situation grows worse each year as economy grows and population pressures increase, especially in Zhangye Prefecture. The main thing in future is to save water resources by economical use with a view to accelerating economic growth in Heihe valley. Simultaneously the areal variation of artificial foresty and man-made pastures from 1995 to 2050 shows that the market value laws will ineffective in dealing with the relationship of economic growth and ecology environment.