Temporal and Spatial Variations of Water Resources Constraint Intensity on Urbanization in Arid Area
干旱区水资源对城市化约束强度的时空变化分析

Water resources constraint force on urbanization has become one of the important exogenic forces which exert great influence on the speed of urbanization process and socio-economic development in arid and water deficient regions. It is of great significance to the measurement and probing into its temporal and spatial variations, thus promoting water resoureces sustainable utilization and accelerating the urbanization process. By qualitative and quantitative methods, an integrated indicator system was constructed, and an AHP model reformed by entropy technology was established to measure the water resources constraint intensity on urbanization. Using this model, the temporal and spatial variations of water resources constraint intensity on urbanization in the Hexi Corridor from 1985 to 2005 were calculated. Results show that: (1) Water resources constraint intensity on urbanization decreased from east to west in the Hexi Corridor. Of the five prefecture-level cities, Wuwei belongs to the very strong constraint type, Jinchang belongs to the strong constraint type, Zhangye belongs to the less strong constraint type to the strong constraint type, Jiuquan belongs to the less strong constraint type, and Jiayuguan belongs to the weak constraint type to the less strong constraint type. (2) Water resources constraint intensity on urbanization has changed into the strong constraint type from the less strong constraint type in recent 20 years. It increased continuously on the whole. However, in recent years, it decreased appreciably. (3) The integrated indexes of water resoureces system and urbanization system in the Hexi Corridor are both comparatively small. Inconsistencies between water shortage and regional development are serious. It is a great challenge to lessen water resources constraint intensity and accelerate the urbanization process. However, most parts in the Hexi Corridor belong to the less strong or strong constraint type. Through rational regulation of water resources constraint intensity on urbanization, the Hexi Corridor can still realize sustainable development.