Non-point source pollution characterization when barrage controlling in Moyang River
It could often bring many complex effects on river water environment when barrage controlling.Based on the rainfall data from January 2022 to June 2023,the opening and closing gate data of Shuangjie Barrage and the Total Phosphorus(TP)concentration data of Jiangcheng water quality automatic monitoring station,the characteristics of the changes of TP in Moyang River under the operation of sluice and dam with combined rainfall and runoff pollution were analyzed.The results showed that the TP concentration in Jiangcheng section was negatively correlated with the water level in front of Shuangjie Barrage gate,and was correlated with the discharge and rainfall.In general,under the influence of non-point source pollution of rainfall,the opening of sluice and releasing water affected the TP concentration of Jiangcheng section to a certain extent.Under the influence of different strategies of sluice-opening operation of Shuangjie Barrage in different months of flood season,the change process of TP concentration in Jiangcheng section was obviously different.During flood season,increasing the gate opening coefficient was helpful to accelerate the migration of pollution masses,reduced the peak value of TP,improved the recovery rate of water quality in the section,and reduced the influence on the average monthly TP concentration in Jiangcheng section.