【摘要】 洞庭湖是我国的第二大淡水湖,近年来出现了水环境质量下降及富营养化等污染问题,非点源污染已成为其主要污染源。本研究在洞庭湖平原堤垸地区建立了分布式非点源污染负荷模型,对洞庭湖平原堤垸地区的非点源氮磷污染负荷的产生量及入河量进行了估算,并对研究区内氮磷污染负荷的流失规律及时空分布特征进行了分析研究。模拟及分析表明,堤垸地区非点源污染负荷以溶解态污染物为主,汛期污染负荷产生量约占年总量的75%;农田径流所产生的氮磷污染物占总量的70%左右,畜禽养殖的贡献率次之;非点源污染负荷的入河系数约为0.7。研究结果可为今后洞庭湖区水环境保护与治理提供参考。更多还原

【Abstract】 Dongting Lake,the second largest freshwater lake in China,is recently subjected to a trend of deterioration of water quality and eutrophication problem,and non-point source pollution has become a major source of its water pollution.In this paper,a distributed non-point source pollution model is developed to estimate the load and discharge amounts of such nitrogen and phosphorus sources in the Dongting polder region,and the causes and the spatial and temporal distribution of such sources over the study area are analyzed.The results of simulation and analysis indicate that dissolved nitrogen and phosphorus are the major sources,about 75% of it generated in flood season.Farmland rainfall-runoff contributes about 70%,and livestock’s contribution to these sources comes next.In the study area,over 70% of these pollutants are discharged into the rivers and lake.This work would be a reference to the protection of Dongting water environments.更多还原