陕西省农业面源污染时空特征及污染源

The temporal and spatial characteristics and pollution source ofagricultural non-point source pollution in Shaanxi Province

为明确陕西省农业面源污染时空特征、重点污染源、污染区域和11个地市区的污染类型。利用输出系数法(ECM)对2010—2019年陕西省11个地市区的农业面源污染总氮(TN)和总磷(TP)的污染负荷进行估算,采用等标污染负荷法对污染源进行评价,通过快速聚类法划分11个地市区农业面源污染类型。结果表明,2010—2019年陕西省农业面源污染TN和TP污染负荷呈先升后降的趋势,2019年TN和TP污染负荷最低,分别为129027.14、13872.84 t;2019年陕西省畜禽养殖、农业种植和农村生活等标污染负荷比分别为20.923%、60.130%和18.947%;不同污染源TN和TP的等标污染负荷空间分布具有很强的一致性,11个地市区农业面源污染等标污染负荷比由大到小依次为榆林市(16.94%)、汉中市(15.42%)、安康市(13.06%)、渭南市(12.93%)、咸阳市(9.28%)、商洛市(8.31%)、宝鸡市(8.18%)、延安市(7.03%)、西安市(6.89%)、铜川市(1.74%)、杨凌示范区(0.24%);11个地市区农业面源污染分为农业种植污染主导型、农业种植+农村生活污染主导型、农业种植+畜禽养殖污染主导型、混合污染型4种污染类型。

In order to clarify the spatiotemporal characteristics,key pollution sources,pollution areas,and pollution types of the agricultural non-point source pollution in Shaanxi Province,the export coefficient method(ECM)was used to estimate the pollution load of total nitrogen(TN)and total phosphorus(TP)in 11 urban areas of Shaanxi Province from 2010 to 2019,and the equal standard pollution load method was adopted to evaluate the pollution sources.The 11 urban areas were divided into agricultural non-point source pollution types using the rapid clustering method.The results showed that from 2010 to 2019,the agricultural non-point source pollution TN and TP pollution load in Shaanxi Province showed a trend of first increasing and then decreasing.In 2019,the pollution load of TN and TP were the lowest,at 129027.14 and 13872.84 t,respectively;in 2019,the equal standard pollution load ratios for livestock and poultry breeding,agricultural planting,and rural life in Shaanxi Province were 20.923%,60.130%and 18.947%,respectively;the spatial distribution of equal standard pollution load for different pollution sources TN and TP showed strong consistency.Among the 11 urban areas,the equal standard pollution load ratios for the agricultural non-point source pollution in descending order were Yulin City(16.94%),Hanzhong City(15.42%),Ankang City(13.06%),Weinan City(12.93%),Xianyang City(9.28%),Shangluo City(8.31%),Baoji City(8.18%),Yan’an City(7.03%),Xi’an City(6.89%),Tongchuan City(1.74%),and Yangling Demonstration Zone(0.24%);the agricultural non-point source pollution in 11 urban areas could be divided into four types:agricultural planting pollution dominant type,agricultural planting+rural life pollution dominant type,agricultural planting+livestock and poultry breeding pollution dominant type,and mixed pollution type.