基于DPeRS模型的海河流域面源污染潜在风险评估

Assessment of Potential Risk of Diffuse Pollution in Haihe River Basin Based Using DPeRS Model

运用DPeRS(diffuse pollution estimation with remote sensing)模型对海河流域面源污染物的空间分布特征和污染来源进行遥感像元尺度解析,结合地表水质评价标准,构建了面源污染潜在风险分级方法,评估了海河流域面源污染潜在风险.结果表明:污染量上,海河流域总氮(TN)、总磷(TP)、氨氮(NH4^+-N)和化学需氧量(COD)面源污染排放负荷分别为429.2、25.7、288.3和1017.0 kg·km^-2,入河量分别为2.5万t、1597.2 t、1.7万t和6.6万t;污染类型上,农田径流是海河流域最主要的氮磷型(TN、TP和NH4^+-N)面源污染源,对于COD指标,城镇生活是首要污染类型,其次为畜禽养殖;空间分布上,海河流域中部和南部地区面源污染负荷较高,此区域也是该流域面源污染高风险集中分布区,氮磷型面源污染高风险区域分布相对较为集中,化学需氧量型则较为零散;海河流域有36%以上的区域存在氮磷型面源污染风险,有2.94%的区域存在化学需氧量型面源污染风险.

Considering the Haihe River Basin as an example,the DPeRS model was used to analyze the spatial distribution characteristics and pollution sources of the diffuse pollution by remote sensing pixel scale.Combined with the evaluation standard of surface water quality,a potential risk grading method for diffuse pollution was constructed to assess the potential risk of diffuse pollution in Haihe River Basin.The results showed that,in 2016,the diffuse discharge loads of total nitrogen(TN),total phosphorus(TP),ammonia nitrogen(NH4^+-N),and chemical oxygen demand(COD)were 429.2,25.7,288.3,and 1017.0 kg·km^-2,respectively,with the amount of river entry being 2.5×10^4 ton,1597.2 ton,1.7×10^4 ton,and 6.6×10^4 ton in Haihe River Basin,respectively.Farmland runoff is the most important source of diffuse pollution of TN,TP and NH4^+-N in the Haihe River Basin.For COD index,urban life is the primary type of pollution,followed by livestock.The diffuse pollution is relatively severe in the central and southern areas of Haihe River Basin,and this area is also a high-risk concentrated distribution area of diffuse pollution in the basin.The distribution of high-risk areas of nitrogen-phosphorus diffuse pollution are relatively concentrated,and the chemical oxygen demand is relatively scattered.More than 36%of the Haihe River Basin has a nitrogen-phosphorus diffuse pollution risk,and 2.94%of the area has a chemical oxygen demand diffuse pollution risk.