A STUDY ON VALLEY—CITY POPULATION CAPACITY IN WESTERN CHINA——TAKING TIANSHUI CITY AS AN EXAMPLE
研究了河谷型城市人口承载力的测算方法，从河谷土地空间、可用水资源和生态环境三个因素出发，以天水市为例计算了最优和最大人口容量。
Population capacity is a strategic problem of valley-city development. It includes optimal population capacity and maximal population capacity.In this paper main influence factors of population capacity in the valley-city are analyzed.In succession,based on three factors of valley land space,usable water resources and eco-environment,measurable method of population capacity in the valley-city is probed into and introduced principally.Firstly,to the valley land space,the authors mainly analyze per capita land criteria,and then compute the population capacity of valley land space through total usable land areas.Secondly,the problem of usable water resources in the valley-city is discussed according to the criteria of per capita comprehensive use water quantity,and then population capacity might be obtained through the whole usable water resources.Finally,population capacity calculation methods of eco-environment are probed into and summarized by per capita urban greenbelt criteria.Taking Tianshui city as an example,optimal and maximal population capacity are respectively calculated via the methods mentioned.Through population capacity calculation of valley land space,optimal and maximal population in Tianshui city respectively is 0.735 million and 1.098 million;through that of usable water resources,optimal and maximal population is equal to 0.7766 million and 2.1139 million;and through that of eco-environment,optimal and maximal population is 0.7337 million and 1.1696 million.According to restriction theorem,the authors draw the basic conclusion that under present conditions optimal population capacity is 0.7337 million and maximal population capacity is 1.098 million in Tianshui city.