本文以喀斯特山区清水江流域鱼梁江河段为研究对象，在查明地下水排泄与河流环境容量及其水质之间关系的基础上，采用Daniel趋势检验法和水量—水质同步估测模型等分析了流域水质变化及其污染负荷和核算了多水文情势下的水环境容量等。结果表明，流域污染负荷为：氨氮（NH3-N）312.85 t/a，总磷（TP）274.91 t/a，氟化物（F-）311.82 t/a，主要为城镇生活和工业污染排放且具明显空间分布特征。控制单元Ⅰ的F-浓度显著下降，水环境容量未超载；控制单元Ⅱ和Ⅲ的TP、F-和NH3-N浓度均显著下降，前者水环境容量均超载，后者TP为过载状态；控制单元Ⅳ主要污染物浓度无明显升降趋势，但TP和F-出现超载，TP严重超载为枯竭状态；控制单元Ⅴ的TP和F-浓度显著下降，水环境容量均为超载状态，亟待实施NH3-N、TP和F-污染物总量控制和精准削减措施。

In this project, Yuliangjiang river section in Qingshuijiang river basin was investigated in karst mountains area. Based on the identification of relationship between groundwater discharge and river water environmental capacity （WEC）and its water quality, the water quality trend and pollution load was analyzed with Daniel trend analytical method and synchronized estimation model of water quantity and quality. And the WEC was calculated in multi-hydrological situation. The results show that the pollution load of ammonia nitrogen(NH3-N), total phosphorus(TP) and fluoride(F-) is 312.85t/a, 274.91 t/a and 311.82 t/a in the basin, respectively. These pollutants originate mainly from industrial and urban sewage and characterized by obvious spatial distribution. In control unit Ⅰ, the concentrations of fluoride had a significant decrease, the WEC of the main pollutants was not overloaded. In control unit Ⅱ and Ⅲ，the concentrations of TP , F- and NH3-N, had a considerable decrease, the former’s WEC of the main pollutants were overloaded, the latter’s WEC of TP was overloaded. In control unit Ⅳ, the concentrations of the main pollutants had not a unobivious increase or decrease, but the WEC of TP and F- were overloaded, and WEC overload of TP was exhausted. In control unit Ⅴ, the concentrations of TP and F- had a remarkable decrease，the WEC of the main pollutants were overloaded, these five control units need to be implemented for total pollutant control including NH3-N, TP as well as F-, and accurate reduction measures.