宁夏农业面源污染及其影响因子解析

为探明宁夏农业面源污染特征及其主要影响因子,运用等标污染负荷法、主成分分析法、灰关联分析法,以地级市为单元研究宁夏种植业、养殖业、农村生活等农业面源污染来源化学需氧量(COD)、总氮(TN)、总磷(TP)的负荷、特征以及主要影响因素。结果表明,宁夏农业面源污染最主要污染源为畜禽养殖,其等标污染负荷比达到30.38%,最主要污染物为TN,其等标污染负荷比达到61.67%。农业面源污染程度银川市、吴忠市为严重污染,中卫市为中度污染,石嘴山市、固原市为轻度污染。宁夏农业面源污染的主要影响因子依次为畜牧业产值、农业产值、农业耗水量、有效灌溉比例、农民人均收入、秸秆利用率、人均农业产值、农业人口、化肥施用量和耕地面积。

Analysis of Agriculture Non-point Source Pollution and its Influence Factors in Ningxia

In order to understand the characteristics of agricultural non-point source pollution(NPSP) and its influence factors in Ningxia,taking prefecture city as basic unit,the equivalent standard method were conducted to determine the discharge amount and regional difference of chemical oxygen demand(COD),total nitrogen(TN) and total phosphorus(TP) from different types of agricultural non-point sources,including planting,breeding,rural life.Principal component analysis and gray correlation analysis method were conducted to study the factors affecting agricultural non-point source pollution in Ningxia.The results showed that the primary pollution source was livestock breeding whose load ratio in equivalent standard reached 30.38%,and the primary pollutant was TN whose load ratio in equivalent standard reached 61.67%.According to pollutant loading and clustering analysis of NPSP,Yinchuan and Wuzhong city were heavily polluted,Zhongwei city was moderately polluted,Shizuishan and Guyuan city were lightly polluted.The significance of the factors which had affected on NPSP in Ningxia was in the order of animal husbandry production value,agricultural output value,agricultural water consumption,irrigation efficiency ratio,the per capita income of farmers,straw utilization,per capita agricultural output value,agricultural population,chemical fertilizer application and cultivated land area.