淮河流域农业非点源污染空间特征解析及分类控制

农业非点源污染是导致流域水质恶化的重要原因,识别流域内关键源区并加以重点控制是流域非点源污染治理的最有效手段.以淮河流域为研究对象,采用清单分析法核算了流域173个县(市、区)的畜禽养殖、农村生活、农田种植、水产养殖4种污染源化学需氧量(COD)、总氮(TN)、总磷(TP)排放量和排放强度.利用SPSS和GIS软件对污染排放强度进行聚类分析、敏感性评价及空间解析,解析出流域非点源污染的敏感地区、重点污染源及其空间分布特征,并依据污染源贡献大小对流域进行分类控制.结果表明,2009年淮河流域农业非点源COD、TN、TP排放量分别为206.74×104t、66.49×104t、8.74×104t;排放强度分别为7.69、2.47、0.32 t·hm-2;COD、TN、TP排放比重分别为73%、24%、3%.识别出COD、TN、TP的主要贡献污染源为畜禽养殖和农村生活;解析出淮河上游沙河、颍河、北汝河、贾鲁河以及清潩河等子流域为整个流域非点源污染的敏感区和优先控制区,畜禽养殖为流域优先控制区中的重点污染源.畜禽污染型和综合污染型分别是流域污染贡献率最高和控制难度大的污染类型.

Spatial Heterogeneity and Classified Control of Agricultural Non-Point Source Pollution in Huaihe River Basin

Agricultural non-point source pollution is of importance in river deterioration. Thus identifying and concentrated controlling the key source-areas are the most effective approaches for non-point source pollution control. This study adopts inventory method to analysis four kinds of pollution sources and their emissions intensity of the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in 173 counties (cities, districts) in Huaihe River Basin. The four pollution sources include livestock breeding, rural life, farmland cultivation, aquacultures. The paper mainly addresses identification of non-point polluted sensitivity areas, key pollution sources and its spatial distribution characteristics through cluster, sensitivity evaluation and spatial analysis. A geographic information system (GIS) and SPSS were used to carry out this study. The results show that: the COD, TN and TP emissions of agricultural non-point sources were 206.74×10⁴ t, 66.49×10⁴ t, 8.74×10⁴ t separately in Huaihe River Basin in 2009; the emission intensity were 7.69, 2.47, 0.32 t·hm^-2; the proportions of COD, TN, TP emissions were 73%, 24%, 3%. The paper achieves that: the major pollution source of COD, TN and TP was livestock breeding and rural life; the sensitivity areas and priority pollution control areas among the river basin of non-point source pollution are some sub-basins of the upper branches in Huaihe River, such as Shahe River, Yinghe River, Beiru River, Jialu River and Qingyi River; livestock breeding is the key pollution source in the priority pollution control areas. Finally, the paper concludes that pollution type of rural life has the highest pollution contribution rate, while comprehensive pollution is one type which is hard to control.