基于清单分析法对 2010—2019 年南水北调中线水源地农业面源污染物 TN 和 TP 的排放量进行测算，并结 合 ArcGIS 软件对其时空演变特征进行分析。结果表明：2010—2019 年，南水北调中线水源地农业面源污染物 TN 负荷和 TP 负荷整体上呈现先增加后减少的趋势；TN 和 TP 污染强度呈先升后降趋势；化肥、畜禽养殖和农村 生活是水源地农业面源污染 TN 和 TP 负荷的主要来源，且化肥比重缓慢增加，畜禽养殖比重不断下降，农村生活 比重不断增加。研究结果可为中线水源地农业面源污染治理、生态保护等方面政策及措施的制定提供决策 支持。

The?South-to-North?Water?Transfers?Project?has?become?the?water?supply?lifeline?of?cities?along?the project?and?plays?an?important?supporting?role?in?their?economic?and?social?development?and?eco-environment protection.?As?several?water?pollution?controls?and?soil?and?water?conservation?plans?have?taken?effect,?non-point source?pollution?is?becoming?the?main?factor?affecting?the?water?quality?To?ensure?continuous?water?supply,?it?is?of great?significance?for?water?quality?protection?to?analyze?the?evolution?characteristics?of?non-point?source?pollution in?the?water?source?area?of?the?middle?route?project. ??????The?inventory?analysis?method?is?used?to?calculate?non-point?source?pollution?load?in?the?water?source?area. Three-level?structure?including?category,?unit,?and?index?was?used?to?analyze?the?main?agricultural?non-point?source pollution?sources.?The?calculation?formulas?of?non-point?source?pollution?load?in?the?water?source?area?were?formed using?pollution?coefficients.?The?non-point?source?pollution?loads?of?TN?and?TP?from?2010?to?2019?of?regions?in water?source?areas?were?calculated,?and?the?spatial?and?temporal?evolution?characteristics?of?the?non-point?source pollution?load?of?regions?in?water?source?areas?were?analyzed?with?ArcGIS. ??????From?2010?to?2019,?the?overall?trends?of?TN?and?TP?load?of?non-point?source?pollution?in?the?middle?route increased?first?and?then?decreased.?The?pollution?intensities?of?TN?and?TP?also?increased?first?and?then?decreased. The?trends?of?structural?characteristics?of?TN?and?TP?of?non-point?source?pollution?in?water?source?were?the?same. Chemical?fertilizer,?livestock?and?poultry?breeding,?and?rural?life?were?the?main?source?of?non-point?source?pollution TN?and?TP?in?water?source.?Chemical?fertilizer?accounted?for?the?largest?proportion?and?its?proportion?showed?a slowly?increasing?trend,?the?proportion?of?livestock?and?poultry?breeding?kept?declining,?and?the?proportion?of?rural life?was?increasing. ??????The ?control ?activities ?of ?non-point ?source ?pollution ?of ?water ?source ?areas ?in ?the ?middle ?route ?should ?be continuous.?Rural?household?should?be?guided?and?encouraged?to?use?environmental?friendly?organic?fertilizers. Other ?activities ?also ?need ?to ?be ?carried ?out, ?such ?as ?improving ?rural ?infrastructures, ?establishing ?a ?system ?for collecting,?transporting,?and?disposing?of?rural?household?waste,?and?promoting?the?utilization?of?rural?household waste?as?resources.