仿自然人工湿地系统构建模式与效果初探

Construction Model of Nature-imitated Artificial Wetland System and its Effectiveness

永定河八号桥湿地系统在秉承生态自然理念下模拟天然湿地特征,充分利用河滩地空间及地形,综合溪流、生态塘、表流湿地和潜流湿地等多种形态,并结合人工湿地构建经验和技术要点构建大型的仿自然复合功能湿地系统,在北京地区尚属首例。初期效果表明:系统运行水力负荷0.076 m^3/(m^2·d),上游来水主要水质指标介于地表水Ⅳ~Ⅴ类条件下,对CODCr、TN、TP和NH4+-N的去除率分别达到22.64%、47.78%、51.67%和21.58%,系统出水主要污染物指标达到优于地表Ⅳ类标准。基于多种形态湿地的优化组合,形成多样化生境格局,有效促进了周边区域生态系统的恢复和景观环境的整体改善。

The wetland system of bridge 8 on Yongding River takes the conception of ecology and nature and simulates the characteristics of natural wetland,it is the first case in Beijing that a large-scale andnature-imitated artificial wetland system with complex functions was constructed by making full use of the river flood bed and its terrain,integrating various forms of wetland such as streams,ecological ponds,surface and sub-surface flows,and combining experiences in and key techniques of artificial wetland construction.Early effectiveness shows that the operational hydraulic loading rate of the system was 0.076 m^3/(m^2•d),under the condition of the main quality indicators of the upstream water between classⅣandⅤof surface water quality standards,the removal efficiency of CODCr、TN、TP and NH4+-N reached 22.64%,47.78%,51.67%and 21.58%,the quality indicators of the outflow effluent were better than classⅣof the standards.Based on the optimized combination of various wetland forms,the diversified habitat pattern is formed,which effectively promotes the restoration of ecosystem and the overall improvement of landscape environment in the surrounding area.