中文摘要：

基于流域或区域点源和非点源磷入河过程的水文学差异,以及影响河流持留作用的主要机制,建立了描述河流段末磷负荷量与流量和水温之间定量关系的二元统计模型;通过逐月的河流水文水质监测数据对模型中4个系数的有效校正和验证,实现了对点源和非点源磷入河过程的准确定量.与现行的水文估算法相比,该模型既考虑了河流磷的持留能力及其时间变异性,也考虑了上游水体输入的磷负荷量,推进了对磷污染过程的定量认识,满足了我国以行政区为主要水污染控制管理单元的现实需要.应用该模型,计算了浙江长乐江集水区2004～2009年的总磷（TP）入河量.结果表明,TP年入河总量为（54.6±11.9）t.a-1,其上游水体输入、点源和非点源的入河量贡献率分别为5%±1%、12%±3%和83%±3%.夏季5～6月和8～9月的非点源TP累计入河量占其全年的50%±9%,增加了引起下游水体藻类暴发的风险.河流TP持留量为（4.5±0.1）t.a-1,占年入河总量的9%±2%;5～9月的TP累计持留量占全年的55%±2%,表明河流持留能力对流域或区域磷素迁移转化过程的调控作用不容忽视.本研究建立的二元统计模型仅需常规的河流水文水质监测数据,无需专业软件知识,且计算结果直接来源于实际的河流水文水质测算值,为实施流域或区域磷污染总量控制策略提供了一种简便、实用、可靠的定量工具.

英文摘要：

Based on the hydrological difference between the point source（PS） and nonpoint source（NPS） pollution processes and the major influencing mechanism of in-stream retention processes,a bivariate statistical model was developed for relating river phosphorus load to river water flow rate and temperature.Using the calibrated and validated four model coefficients from in-stream monitoring data,monthly phosphorus input loads to the river from PS and NPS can be easily determined by the model.Compared to current hydrological methods,this model takes the in-stream retention process and the upstream inflow term into consideration;thus it improves the knowledge on phosphorus pollution processes and can meet the requirements of both the district-based and watershed-based water quality management patterns.Using this model,total phosphorus（TP） input load to the Changle River in Zhejiang Province was calculated.Results indicated that annual total TP input load was（54.6±11.9） t·a-1 in 2004-2009,with upstream water inflow,PS and NPS contributing to 5%±1%,12%±3% and 83%±3%,respectively.The cumulative NPS TP input load during the high flow periods（i.e.,June,July,August and September） in summer accounted for 50%±9% of the annual amount,increasing the alga blooming risk in downstream water bodies.Annual in-stream TP retention load was（4.5±0.1） t·a-1 and occupied 9%±2% of the total input load.The cumulative in-stream TP retention load during the summer periods（i.e.,June-September） accounted for 55%±2% of the annual amount,indicating that in-stream retention function plays an important role in seasonal TP transport and transformation processes.This bivariate statistical model only requires commonly available in-stream monitoring data（i.e.,river phosphorus load,water flow rate and temperature） with no requirement of special software knowledge;thus it offers researchers and managers with a cost-effective tool for quantifying TP pollution processes in both district and watershed scales.