基于通量分析方法的河川型水库生态屏障区位设计

Location design of ecological barriers for river-type reservoir based on flux analysis method

区位选择是水生态屏障研究及建设过程中面临的重要科学问题.针对河川型水库入流方式多样、地形起伏大的特征,本研究从水生态屏障的非点源污染去除功能出发,提出一种基于通量分析的河川型水库生态屏障区位选择方法.以我国三峡库区为例,选择库区典型研究区运用该方法进行生态屏障区位研究.结果表明:按照三峡库区沿岸100 m宽度的设计方案,研究区内水生态屏障作用不能得到有效发挥,其中,最佳功能区仅占设计面积的11%,无效区占设计面积的10%,流域内79%的总氮与93%的总磷集中在占生态屏障区总面积21%的区域进入水库.根据污染物通量及流量通量过程,可提取出高污染通量汇流区域及高污染物浓度区,根据保护目标,分别对应开展以污染物总量削减及污染物浓度达标的生态工程措施.采用该方法可充分考虑地形对污染物质通量的影响,划分出水生态屏障的重点保护区域,能有效解决河川型水体的水生态屏障区位设计问题.

Location selection is an important scientific issue in the research and construction of water ecological barrier. Considering the characteristics of river-type reservoir with various inflow modes and large topographic fluctuation,we presented a location selection method for ecological barrier of river type reservoir based on flux analysis with the removal function of non-point source pollution of water ecological barrier. Using this method,we examined the ecological barrier location in the Three Gorges Reservoir area of China. The results showed that the role of ecological barrier for water in the study area could not be brought into full play according to the design plan of 100 m width along the coast of the Three Gorges Reservoir area. The zone of optimal function accounted for11% of the design area,and ineffective zone accounted for 10% of the design area. 79% of the total nitrogen and 93% of the total phosphorus were concentrated in the area accounting for 21% of the total ecological barrier area and entered the reservoir. According to the flux of pollutants and their process of flow and flux,we extracted the confluence area of pollutants with high flux and area with high pollutant concentration. Based on the protection target,the ecological engineering measures to reduce the total pollutants and ensure the standard reaching of pollutant concentration were carried out respectively. This method,with full consideration of the influence of terrain on pollutant flux and classification of the key protected areas in water ecological barrier,could effectively solve the problem of location design of water ecological barrier in river-type water.