茅洲河流域地表水与地下水交互关系模拟和污染联合防治

在茅洲河流域地表水与地下水补排关系定性分析的基础上，建立SWAT和SWAT-LUD模型对流域水的循环转化过程进行数值模拟，定量计算地表水与地下水的交互量并估算污染贡献量。结果显示:2017年地下水排泄补给河水水量为1.6×108 m3，携带的NH₃-N、TP和COD总量分别为0.9×104，0.2×104，1.7×104 t，约占河流总污染指标的3%；地表水侧向补给地下水水量为1.0×106 m3，携带的NH₃-N、TP、COD量分别为11，1.1，510 t，约占地下水补给地表水污染指标总量的2%；洪水泛滥区河水入渗补给地下水水量为6.7×106 m3。基于以上研究，建议采取河道底泥清淤、建设交互带渗透式反应墙、河口建闸、交互带水污染预警与监测等工程措施对茅洲河流域地表水与地下水污染进行联合防治。

THE INTERACTIVE MODELING AND JOINT PREVENTION OF WATER POLLUTION BETWEEN SURFACE WATER AND GROUNDWATER IN MAOZHOU RIVER BASIN

Based on the qualitative analysis of relationship of recharge and discharge between surface water and groundwater in Maozhou River Basin, we established SWAT and SWAT-LUD models to simulate the circulation and transformation process of watershed water, quantified the interactive volume between surface water and ground water, and estimated the pollutant contribution. The results showed that the volume of groundwater recharge to surface water was 1.6×108 m3 in 2017, with the amount of NH₃-N、TP and COD at 0.9×104, 0.2×104 and 1.7×104 t, respectively, and approximately contributed 3% of the total river pollutants; the volume of surface water recharge to groundwater was 1.0×106 m3, with the amount of NH₃-N, TP and COD at 11 t, 1.1 t and 510 t, respectively, and contributed 2% of the total pollutants of groundwater recharge surface water; the amount of groundwater recharged by river water infiltration in flood area was 6.7×106 m3. On the basis of above research, we suggested to adopt engineering measures, such as sediment dredging, construction of permeable reaction wall in interactive zone, building sluice on river estuary, watershed water environmental early-warning and monitoring in interactive zone, to implement joint prevention of surface water and groundwater pollution in Maozhou River Basin.