干旱区水资源对城市化约束强度的时空变化分析

水资源对城市化的约束力已经成为干旱缺水地区决定城市化发展速度,进而决定城市化和社会经济发展规模的重要外营力之一,科学度量并探讨其时空变化,对水资源可持续利用与城市化正常推进具有重要意义。以定性与定量分析相结合的方法建立了水资源对城市化约束强度的综合测度指标体系,采用熵技术支持下的层次分析法构建出水资源对城市化约束强度的综合测度模型,并对1985-2005年河西走廊水资源对城市化约束强度的时空变化进行了分析。结果表明,河西走廊水资源对城市化的约束强度在空间上总体表现为自东向西逐渐减小,在时间上表现为由较强约束类型变为强约束类型,总体呈不断增加态势,但近年来略有缓解。虽然河西走廊水资源开发利用潜力综合指数与城市化系统综合发展指数都较低,面临缺水和发展的双重矛盾,但目前河西走廊大部分地区水资源对城市化的约束强度仍属于较强或强约束类型,仍然能够通过合理调控实现可持续发展。

Temporal and Spatial Variations of Water Resources Constraint Intensity on Urbanization in Arid Area

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.