洋河水库泄洪对近岸海域水质的影响

基于验证良好的秦皇岛河流-海岸一二维耦合数学模型，探讨了洋河水库泄洪对近岸海域水质的影响。由于水库COD浓度略高于近岸海域COD标准浓度，但远低于河道水体COD浓度，水库开闸放水初期，河口海域COD日平均浓度和超标面积较泄洪前有所增大，此后随着水库的不断泄洪，海域COD日平均浓度和超标面积逐渐减小，最终趋于稳定，海域水质较泄洪前得到明显改善。在相同水库放水COD浓度下，泄量越大，携带水库下游河道的污染物入海越多，海域COD日平均浓度超标面积越大，且泄量与超标面积间服从线性函数关系。在污染物入海通量相同的情况下，减小污染物入海浓度在一定程度上可以改善近岸海域水质状况。

Influences of the Yanghe reservoir flood discharges on water quality in coastal waters

Based on the well calibrated 1D and 2D coupled numerical model for rivers and coastal waters of Qinhuangdao, the influences of the Yanghe reservoir flood discharges on water quality in coastal waters were discussed. Due to COD concentration in the reservoir is slightly higher than COD standard concentration of coastal water and considerably lower than COD concentration of the river, which leads to the daily average concentration of COD and over-standard area of COD concentration will increase in the estuaries at the beginning of reservoir water release. Then with the continuous release of reservoir water, the daily average concentration of COD and over-standard area will gradually decrease, and finally tend to be stable. Hence, the water quality of coastal water will be significantly improved. Under the same COD concentration in reservoir, the more discharge of reservoir water will carry more downstream pollution to the coast, the larger of over-standard area in coastal water, and the relationship of reservoir flood discharge and over-standard area can be well fitted by a linear function. In the case of the same pollutant flux into the coastal water, reducing pollutant concentration will improve water quality of coastal water.