为分析强降雨导致面源污染入库对库区水质的影响,以大伙房水库为例,构建库区三维水动力及水质模型,分析了强降雨过程中库区三维水动力及污染物浓度空间变化特征。结果表明:当入库流量较大时,库区水流场主要受吞吐流影响。污染团在水流输移作用下向下游迁移扩散,最大浓度及影响范围随时间先增加后逐步减小。当入库流量逐步减小时,吞吐流的影响逐步减弱,水流场变化受吞吐流和风生流共同支配。污染团在迁移过程中受此影响,浓度在三维方向呈现相应变化特征。研究结果可为制定更为切实可行的面源污染治理措施提供技术参考。

To obtaining the influence of non-point source pollution caused by heavy rainfall on the water quality of reservoir, a 3-D hydrodynamic and water quality model is established to analyze the changes in 3-D hydrodynamics and spatial distribution of pollutant concentration in Dahuafang reservoir during heavy rainfall. Result show that in the presence of large inflow, the flow field in reservoir area is mainly affected by inflow and outflow; pollutants migrate and diffuse towards the downstream with the flow process, and the maximum concentration and influence range increase and then decrease with the passing of time. When inflow gradually reduces, the influence of stream flow on reservoir flow field gradually weakens while the effect of wind-driven flow gradually intensifies, which suggest that the flow field is controlled by both the inflow and outflow and the wind-driven flow. In the course of migration, pollutant concentration presents corresponding changing characteristics in three dimensions.