中文摘要：

晋江金鸡闸断面是泉州市重要饮用水取水口断面,其水质安全对实现区域经济社会发展具有重要意义.以晋江金鸡闸断面水文水质监测资料为基础,借助水文统计及降雨径流与面源污染关系分析,提出确定不同水平年典型污染物质量浓度年际及年内变化的方法,进而确定面源污染负荷和水质敏感期.结果表明：从枯水年到丰水年,CODMn、NH3-N、TP的面源污染贡献率随降雨径流量的增多而增大,分别为30%-74%、53%-61%、39%-62%;ρ（NH3-N）和ρ（TP）的年均值随降雨径流量的增大而减小,ρ（CODMn）与降雨径流量关系不密切.在丰水年、偏丰年及平水年ρ（CODMn）、ρ（NH3-N）、ρ（TP）的年均值变化均较小,而在偏枯年和枯水年变化较大;三者年内变化规律相近,ρ（NH3-N）和ρ（TP）的峰值一般出现在3月、4月,并且峰值大小与年降雨径流量呈反势,ρ（CODMn）峰值及与年降雨径流量关系不明显.除3月、4月外,ρ（CODMn）、ρ（NH3-N）大多达到GB 3838—2002《地表水环境质量标准》Ⅱ类水质标准限值,而ρ（TP）基本达到Ⅲ类水质标准限值.

英文摘要：

Jinji Sluice Section of Jinjiang River is the source of drinking water for Quanzhou City,Fujian Province. Protecting the water quality is significantly important to the regional economic and social development. Based on officially compiled hydrological data and observed water quality data,monthly concentration curves of three typical pollutants-CODMn,total phosphorus（ TP） and ammonia nitrogen（ NH3-N）-for years with different levels were depicted by the methods of hydrological statistics and analysis of the relationship between rainfall-runoff and area source pollution. The area source pollution load ratio and the fragile water quality period were further determined.The results showed that the area source ratio to the total pollutant load increased with increasing annual rainfall-runoff,ranging from 30%to 74% for CODMn,53% to61% for NH3-N and from 39% to 62% for TP,when the runoff level shifted from extremely poor（ P = 90%）to extremely rich（ P = 10%）. There was a minor difference in annual average concentration of the three pollutants among average（ P =50%）,rich（ P = 25%） and extremely rich（ P = 10%） runoff level years,while a rel7atively big gap occurred for concentrations between poor（ P = 75%） and extremely poor（ P = 90%） runoff level years. The average concentrations of NH3-N and TP had a similar monthly trend,and tended to arrive at an apex in March or April. The maximum values negatively correlated with annual rainfall-runoff. Although the maximum concentration of CODMnalways occurred in March,a small gap occurred between the apex and other monthly concentrations.According to China＇s Surface Water Quality Standard,with the exception of March and April,the other monthly concentrations of NH3-N and CODMncould almost satisfy the second class,while those of TP could meet the third class.