西北地区城市化过程中水资源约束时空变化--以西陇海兰新经济带甘肃段为例

摘要

Based on more than 2 000 data associated with the urban system and water-resource system from 1989 to 2007, a comprehensive quantitative measurement was made of the constraint intensity of water resources on urbanization and of its temporal-spatial variations, with the conclusion that 1) In the time series the WRCI (water resource constraint intensity) in Gansu section and its nine cities has showed a trend of fluctuating down as a whole, which had decreased faster since 2000 with Lanzhou and Jinchang as the representative cities. Among nine cities there had been different constraint intensities. Particularly, the WRCI of Lanzhou had decreased from the intensive constraint in 1989 to the strong constraint with an obvious drop in 2007. The WRCI of five cities changed from the extreme constraint to the intensive constraint, namely Wuwei and Jiuquan having an obvious drop, Jiayuguan and Jinchang a small drop and Dingxi a fluctuating down;with a small drop of the WRCI, Baiyin and Zhangye in general maintained an extreme constraint and Tianshui maintained an intensive constraint. 2) In term of spatial differentiation, the 20-year mean of WRCI showed that water resources had constrained urban development with the type of a relatively strong constraint in Lanzhou, the type of the intensive constraint in Tianshui, and the type of the extreme constraint in the other 7 cities including Jiuquan, Jiayuguan, Zhangye, Jinchang, Wuwei, Dingxi and Baiyin, indicating that the Gansu section will be confronted with more problems of water shortage and adjustment of water resources in the future.%　　基于甘肃段1989−2007年近20年水资源与城市化两大系统的2000多个数据，采用改进的综合测度模型，探讨了甘肃段水资源对其城市化发展约束强度的时空变化.研究表明：1)1989−2007年甘肃段及其9个城市水资源约束强度总体上呈下降趋势，特别是自2000年以来，约束强度下降趋于加快，其中兰州市、金昌市最为突出.但9个城市之间，水资源约束强度变化存在一定差异，反映了变化的丰富性.具体来说，兰州市由强约束降为较强约束，降幅明显；由极强约束降为强约束的城市有5个，包括约束度降幅较大的武威市、酒泉市，降幅不明显的嘉峪关市、金昌市及约束度呈波动变化的定西市；约束度略有下降，但约束类型基本不变的城市包括白银市(极强约束)、天水市(强约束)与张掖市(极强约束).2)甘肃段9个城市水资源约束空间差异按20年约束度平均计，表现为除兰州水资源约束类型属于较强约束、天水市属于强约束外，其余7个城市(酒泉、嘉峪关、张掖、金昌、武威、定西、白银)均属于极强约束，反映甘肃段城市化发展整体一直承受着较大的水资源压力，未来一定时期水资源约束压力也会依然存在.