2014－2019年钦江河口典型污染物的入海通量研究

基于2014－2019年钦江入海河口断面流量以及化学需氧量（COD）、总氮（TN）和总磷（TP）3种典型污染物的浓度，本研究通过LOADEST模型优化了COD、TN和TP入海通量计算方程，其优化后的判定性系数分别为0.857、0.772和0.717，这说明优化后的方程能够满足钦江河口典型污染物入海通量及水质变化特征的评估。结果表明:（1）2014－2019年，COD、TN和TP无论是浓度还是通量均呈现先升高后降低的变化趋势，TN依然超标严重；（2）COD、TN和TP季节变化特征显著（p<0.01），入海通量干季低于湿季，浓度干季高于湿季，COD和TN的入海通量与降雨量呈极显著相关性（R2=0.897，p<0.01，R2=0.748，p<0.01），COD和TN主要来自非点源，而TP与降雨量呈显著相关性（R2=0.359，p<0.05），TP不仅受非点源影响，也受点源影响，建议加强沿江污水管网和污水处理能力建设。

Study on the discharged flux of typical pollutants in Qinjiang river estuary from 2014 to 2019

The regression equations of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) fluxes were optimized by LOADEST model based on the discharge and water quality data of Qinjiang river from 2014 to 2019. The R2 value for COD, TN, and TP was 0.857, 0.772 and 0.717, respectively. This indicated that the optimized equation could be used to evaluate the variation characteristics of typical pollutants fluxes in Qinjiang river. The results showed: (1) From 2014 to 2019, both concentrations and fluxes of COD, TN, and TP showed a trend of increasing first and then decreasing, and TN still exceeded seriously the water quality standard; (2) The seasonal variation characteristics of COD, TN and TP were significant (p<0.01). The fluxes of COD and TN in wet season were higher than in dry season, indicating that they were strongly driven by rainfall, while their concentrations in dry season were higher than in wet season, suggesting that COD and TN were mainly influenced by non-point sources. Although TP was significant correlated with rainfall, its concentration was also mostly influenced by nonpoint sources. Overall, this study suggested that the construction of sewage pipe network and sewage treatment capacity should be strengthened along the river channel. This will help to curb pollutants input into the river system.