流域尺度农业磷流失危险性评价与关键源区识别方法

农业非点源磷污染是我国农村水环境面临的严重问题之一,由于非点源污染治理难度大,所以识别流域内磷流失的关键源区成为非点源磷污染评价的主要目的.本文在分析流域尺度磷流失危险与分级方案的基础上,根据Gburek等提出的方法,建立了适合我国北方农业区流域尺度磷流失危险评价、分级与关键源区识别的方法.修正的流域尺度磷分级方案重点选取了8个评价因子,分别赋予不同的权重;每个因子的危险性等级根据我国的行业标准和实际情况进行了调整.评价得到的"高"危险性区域就是流域内磷流失的关键源区.这一分级评价方案考虑了数据的可获得性和评价的定量性,在确定各因子时注重与GIS技术、地统计学等方法的结合,具有较强的可操作性和实用性.

Catchment scale risk assessment and critical source area identification of agricultural phosphorus loss

Agricultural non-point source phosphorus pollution is a severe problem for rural water bodies in China,but hard to control directly because of its special characteristics.In this paper,an approach on the catchment scale risk assessment and critical source area identification of agricultural phosphorus loss in northern China was made,based on the catchment scale phosphorus ranking scheme and the method proposed by Gburek et al.Eight factors were selected and weighed in the modified catchment scale phosphorus ranking scheme,and the phosphorus loss risk rating of each factor was adjusted based on the current professional standards and the actual circumstances in China.The areas with 'high' risk rating of phosphorus loss in definite catchment were the critical source areas for non-point source phosphorous pollution control in that catment.The availability of obtained data and the quantification of the assessment were taken into account in the new scheme,and GIS technique and geostatistics were used for confirming the factors.Therefore,the new scheme had definite operability and practicability.