用灰水足迹方法评价水环境变化，逐渐成为水环境及相关研究的热点之一。为了掌握重庆农业水环境状况，把灰水足迹与农业面源污染联系起来，首先核算重庆2007年种植业灰水足迹，然后对其空间差异进行分析。结果表明①重庆2007年的种植业灰水足迹为22.088 8亿m³;②重庆多数区县种植业灰水足迹密度差异不大;③重庆2007年的种植业灰水足迹强度东部高、西部低;④种植业水环境压力指数西部高、东部低，城市发展新区的13个区县种植业已对水环境造成污染。研究表明，重庆水环境保护要重视种植业产生的污染。

Assessing water environment change by grey water footprint has become a hot topic of water environment related researches. To understand the agricultural water environment in Chongqing, the grey water footprint of crop farming in Chongqing in 2007 was calculated, and the space difference was analyzed by relating grey water footprint with agricultural non-point source pollution. Results showed that 1) the grey water footprint of crop farming in Chongqing in 2007 was 2 208.88×10⁶ m³,which means 2 208.88×10⁶ m³ of freshwater was needed to dilute the pollutants from crop farming for a good condition of water environment; 2) the density of gray water footprint on crop farming in many counties of Chongqing differs slightly; 3) the intensity of gray water footprint on crop farming is high in eastern counties and low in western counties of Chongqing; 4) the pressure index of water environment in western counties is higher than that of eastern counties, and the water environment has been polluted by crop farming in 13 newly-developed counties of Chongqing. The research indicates that more attention should be paid to the pollution from crop farming.