基于源汇过程模拟的鄱阳湖流域总磷污染源解析

近年来鄱阳湖磷污染问题突出，总磷超标且浓度逐年增加，成为制约鄱阳湖流域（江西）经济社会可持续发展的重要因素.为科学解析鄱阳湖总磷污染来源，耦合多污染源污染负荷估算方法和SPARROW模型，建立基于源汇过程模拟的流域污染源解析技术方法，针对鄱阳湖流域13种总磷污染源开展负荷估算、模拟校核和入湖时空贡献定量解析.结果表明:①鄱阳湖总磷负荷以陆域输入为主（占90.8%），主要污染来源为农业和城镇生活源，贡献率分别为56.4%和30.6%；污染来源按贡献率的大小排序依次为种植业（29.3%）>城镇生活（24.6%）>畜禽养殖（17.2%）>水产养殖（9.9%）>内源释放（6.9%）>城市径流（6.0%）>农村生活（2.2%）>工业企业（1.6%）>其他源（0.46%）.②在空间贡献方面，总磷入湖负荷主要来自于滨湖区和赣江集水区，贡献率分别为33.5%和31.8%，其他集水区总磷贡献率较小（合计为25.5%），湖体贡献率为9.2%；同时，不同子流域污染源贡献结构也存在空间差异性.③在时间贡献方面，总磷入湖负荷量呈季节性波动特征，贡献峰值多出现在6月，雨季（3—8月）陆源输入负荷占全年的70%.④所构建的基于源汇过程模拟的污染源解析模型可用于流域水污染来源成因精细化解析.研究显示，鄱阳湖总磷污染来源具有明显时空差异性，建议围绕滨湖区和赣江集水区等高贡献区域设立优先管控区，重点针对种植业、城镇生活、畜禽养殖和水产养殖源，制定磷污染源汇过程减排政策措施，以改善鄱阳湖水环境质量. 

Source Apportionment of Total Phosphorus Pollution in Poyang Lake Basin Based on Source-Sink Process Modeling

In recent years, the total phosphorus (TP) pollution in Poyang Lake has worsened with increasing TP concentration year by year, limiting the sustainable development of the regional socio-economy in the Poyang Lake Basin (PLB) or Jiangxi Province. To completely and quantitatively identify the pollution sources of TP in Poyang Lake, a robust source-sink processes based framework for watershed pollution source apportionment has been developed by combining the traditional load estimation methods with the SPARROW model in this study. The methodology is applied in estimation and validation of TP pollution loads of a total of 13 sources in PLB and quantifying the corresponding spatio-temporal contributions. The results show that: (1) The major part of TP load in Poyang Lake comes from land area (accounting for 90.8% of basinal total), and the main pollution sources are related to agriculture and urban household, accounting for 56.4% and 30.6%, respectively. According to the percentage of contribution from different sources, the TP load contribution structure to Poyang Lake is: planting (29.3%) > urban household (24.6%) > livestock (17.2%) > aquiculture (9.9%) > sediment endogenous release (6.9%) > urban runoff (6.0%) > rural household (2.2%) > industry (1.6%) > other sources (on average 0.46%). (2) From the perspective of spatial contribution, the waterfront area and the Ganjiang watershed are two major contribution areas to Poyang Lake''s TP load, accounting for 33.5% and 31.8%, respectively, and the other watersheds contribute 25.5% of TP load to Poyang Lake. In addition, different subbasins present different pollution source structures. (3) From the perspective of temporal contribution, it shows the seasonal variation of TP load into Poyang Lake and the total TP entering the lake from March to August accounts for 70% of the annual total, with the peak load in June. (4) The developed source-sink processes based on the watershed pollution source apportionment framework can be used to support basinal systematic and refined water pollution apportionment. Based on these findings, it can be concluded that the source of TP load entering Poyang Lake varies temporospatially. We suggest setting priority areas for TP pollution control especially in the Waterfront area and Ganjiang watershed, to carry out policies and measures for TP load reduction from the major sources (including planting, urban household, livestock, aquiculture, etc.) across corresponding source-sink processes, and to improve the water quality in Poyang Lake.