辽河流域湿地水质污染特征及净化效果实证评估

流域湿地是流域生态系统中河岸陆地和河道水体间的水陆过渡地带,在污染物阻控、生物多样性保护、侵蚀泥沙削减等方面有着重要的作用。为揭示辽河流域干流上、中、下游湿地污染物削减特征,量化比较湿地水质净化功能的差异,在对东西辽河交汇口湿地、七星湿地和下游湿地水质及水量进行现场监测的基础上,采用内梅罗污染指数法对其污染状况进行分析,实证评估湿地对污染物的去除效果。结果表明,内梅罗污染指数在支流入口处较高,经过湿地净化作用,在湿地中部及出口处污染程度明显降低;东西辽河交汇口湿地、七星湿地和下游湿地对污染物的去除效果有所差异,这主要是受支流和流域水污染的结构性、复合性、区域性等特征因素影响的结果。

Water pollution characteristics in wetlands and empirical evaluation of purification effect in Liaohe River Basin

Wetlands which are the transition areas between riparian land and river water in watershed ecosystem play important roles in the pollution control, biodiversity conservation and erosion and sediment reduction. In order to reveal the pollutants reduction characteristics of wetlands in the upper, middle and lower reaches of Liaohe River Basin, and to quantitatively compare the differences of the purification effects of the wetlands, the water quality and quantity at the junction of East and West Liaohe River, Qixing Wetland and Liaohe River Estuary Wetland were monitored on the spot, the status of water pollution was analyzed by Nemerow pollution index, and the pollutant removal effect of wetlands was empirical evaluated. The results showed that Nemerow pollution index at the entrance of tributary rivers were higher than that in central wetlands and at wetland water outlets. The water pollution status would be gradually alleviated owing to purification effects of wetlands along with the distance away from the tributary estuary. The reduction effects in the above three wetlands on the pollutants were different mainly due to the structural, complex and regional characteristics of water pollution in the tributary rivers.