河西走廊水资源变化与城市化过程的耦合效应分析

Coupling Effects between Water Resources Change and Urbanization Process in Hexi Corridor of Northwest China

在我国实施西部大开发战略和城镇化战略的过程中,加快西北干旱区城市化进程,对同步加快干旱区的工业化进程和国民经济的生态化进程,全面建设小康社会,对于吸纳农村更多的剩余劳动力就业、改善农村脆弱得生态环境等具有十分重要的现实意义。但西北干旱区城市化进程受到水资源短缺及其用水结构不合理的双重约束。本文以西北干旱区的甘肃河西走廊为例,分析了水资源变化与城市化过程的交互耦合效应。研究认为,河西走廊城市水资源短缺属于结构型短缺中的相对性短缺,城市兴起的第一驱动力是资源和交通,并因水的丰缺而盛衰,城市化进程缓慢的第一制动力不是水,而是弱小的产业集聚力。多重胁迫约束下未来30年的城市化水平只能达到35%左右,只能有约87×104农民进城,城市化水平每提高1%所需城市用水量增加0 91×108m3左右,城市化水平每隔5%间隔的单位城市化水平所需城市用水量越大,取水难度和用水成本也越大。按照城市发展的阶段性规律,在不考虑政策和户籍制度变化等因素的前提下,河西走廊未来城市化水平最高可望达到47%左右。

It is vital to accelerate the process of urbanization in arid area of Hexi corridor of Gansu province in the development of west China, as urbanization in the area could 1) accelerate the process of industrialization and realize economic sustainable development; 2) help to construct a well-off society in an all-round way; 3) absorb more rural surplus labor forces; 4) promote conversion of slope cropland to woodland and grassland, and 5) carry out ecological migration strategy. However, the process of urbanization in the area China is restricted by both scarce water resources and irrational structure of water utilization. The paper aims to analyze coupling effects between water resources change and urbanization process in arid area of Hexi corridor of Gansu province in Northwest China. The results show that water shortage in the cities of Hexi corridor is caused by an irrational water utilization structure, not the total quantity of water resources, therefore, it is a case of relative shortage. The first driving force of urbanization is thus transportation and other resource, rather than water resources; the first restricting factor causing a slow process of urbanization is a weak industrial centralization, rather than water resources. It is forecasted that, under the restriction of multiple factors, only 87×10~4 peasants can migrate to the cities, and the urbanization target can only reach 35% in 2030. It is found that with the increase of urbanization by one percent, water consumption will increase by 0.91×10~8m^3. From 1985 to 2030, when the urbanization standard increases at an intervals of five percent, the urban water consumption will increase at a large extend, and the difficulties in getting water resources and the cost of urban water utilization will be increasing. According to the Law of Urban Development, if not take into consideration of changes of policy and household registration system, the urbanization standard in Hexi corridor can reach 47 percent at the utmost.