Abstract: Based on the collected water resources carrying capacity index system,and with SPSS software,this paper evaluated the spatial-temporal variations of water resources carrying capacity in Gansu Province,China, aiming to provide a theoretical reference for the rational allocation of water resources and related policies in Gansu. Results of the evaluation are different from those of previous results,the higher the score is,the less the water resources carrying capacity is. According to the principal component analysis,the main influencing factors of water resources carrying capacity in Gansu are:economic development factor,population factor,water supply and demand balance factor,and agricultural production water consumption factor. Generally speaking,the water resources carrying capacity of Gansu during 2006-2015 showed a declining trend from -0.93 in 2006 to 0.68 in 2015. The water resources supply and demand balance factor and agricultural production water factor were the most crucial factors to regional water resource carrying capacity. Gannan scored the lowest,which is -0.65,indicating that Gannan had the largest water resources carrying capacity and greatest potential for water development and utilization;however,Lanzhou scored the highest,which reached 1.06,indicating that the water resources carrying capacity in Lanzhou was the smallest,and the development and utilization potential for water resources was the smallest. Water resources carrying capacities of 14 regions are divided into four categories:the first category includes Lanzhou and Jiuquan,where the level of social and economic development is higher and the industrial base is relatively strong,the contradiction between supply and demand of water resources is serious and water pollution is serious;the second category includes Zhangye and Wuwei,where the agricultural production consumes the largest water resources,waste of water resources is serious,and the water resources utilization efficiency is low;the third category includes Baiyin,Tianshui,Jinchang,Qingyang,and Dingxi,where the level of social economy,agricultural production and industrial development,all rank the province's medium level;the fourth category includes Longnan,Linxia,Pingliang,Jiayuguan,and Gannan,where the level of regional economic development is low,the degree of water resources development is low,and the contradiction between supply and demand of water resources is relatively small.

Key words: water resources carrying capacity, principal component analysis, overall evaluation, Gansu Province