Study on current situation and regional characteristic of agriculture non-point source pollution in Shaanxi province | 陕西省农业非点源污染现状与区域特征研究

Chinese. 分析陕西省农业非点源污染现状和区域差异，为农业非点源污染防控提供科学依据。采用陕西省2000－2008年及各地区2008年的畜牧业生产情况、作物产量、生产资料（化肥和农膜）投入、农村人口等统计数据，对陕西省及各地区的农业非点源污染情况进行估算，并利用SPSS软件进行聚类分析。（1）从2000年开始，陕西省营养污染物排放量和等标污染负荷均呈快速上升趋势，并于2006年达到最高值，分别为251.15万t和1 538.747 3亿m3，之后呈下降趋势，2008年分别降为197.02万t和1 197.406 0亿m3。农村生活垃圾和作物秸秆耕地负荷从2000年缓慢增长后，分别于2005和2006年达最大值，之后呈下降趋势，2008年分别为3 054.20和6 175.11 kg/hm2。农膜和化肥投入的耕地负荷则一直保持增加的趋势，2008年分别达到9.69和582.43 kg/hm2。（2）陕西省11个地区农业非点源污染可以分为4类地区：第Ⅰ类地区包括杨凌1个地区，除农膜污染外，营养污染、化肥污染、作物秸秆污染和农村生活垃圾排放均很严重，属于重度污染区；第Ⅱ类地区包括西安1个地区，属于化肥施用过量型的中度污染区；第Ⅲ类地区包括宝鸡、咸阳、铜川、渭南、汉中、安康和商洛7个地区，均属于中度污染区，各指标排放量呈现中等排放水平；第Ⅳ类地区包括延安和榆林2个地区，属于轻度污染区。陕西省农业非点源污染地域差异明显，陕北的延安和榆林农业非点源污染总体较轻；而关中各地区农业和畜牧业发达，农业非点源污染排放总量较大；耕地面积较少的地区，农业非点源污染的耕地负荷较为严重。

English. The current situation and regional differentiation of agriculture non-point source pollution in Shaanxi province were analyzed, which can provide a scientific basis for controlling agriculture non-point source pollution in Shaanxi province. Based on the statistical data of number of livestock, output of crops, agricultural input and rural population in the period of 2000-2008 in Shaanxi province, pollutants discharging amounts of agriculture non-point source pollution in each city and the whole province of Shaanxi were computed, and then the software SPSS was used to make the cluster analysis. (1) Since 2000, discharging amount and equivalent pollution load of nutrient pollutants kept fast increase and reached the maximum value at 251.15×104 t and 1 538.747 3×108 m3 respectively in 2006. Then the values decreased to 197.02×104 t and 1 197.406 0×108 m3 respectively in 2008. Loads of agricultural film and fertilizer kept sustainable growth, and reached 9.69 and 582.43 kg/hm2 in 2008 respectively. (2) Four regional types were classified for agriculture non-point source pollution in Shaanxi province. Type Ⅰ belong to heavy pollution area, which include Yangling, almost all types of pollutants are excessive discharged except for agricultural film. Type Ⅱ belong to middle pollution area with excessive input of fertilizer, which include Xi’an. Type Ⅲ belong to middle pollution area, which include Baoji, Xianyang, Tongchuan, Weinan, Hanzhong and Ankang. Type Ⅳ belong to slight pollution area, which include Yan’an and Yulin. Regional differentiation of agriculture non-point source pollution is obvious in Shaanxi province. Pollution in northern Shaanxi province is generally slight, but largely discharged in Guanzhong basin because of well development of agriculture and livestock breeding. Loads of agriculture non-point source pollution are quite serious for those regions with small cultivated areas.