周期性淹水对消落区水土环境的影响及控制对策

三峡库区消落区生态脆弱,在水土交互作用下消落区土壤母岩风化成土进度加快、土壤侵蚀加剧、土壤氮磷等营养物质及重金属大量溶出,其中N、P、COD和重金属是主要的溶出因子,淹没的耕地是主要的污染源。成库初期消落区生态脆弱性增强、水土流失加剧、地质灾难增加、岸边污染加重,尤其在水流缓慢的库湾将会出现局部的富营养化现象;随着消落区稳定的库岸湿地生态系统的形成,水土耦合呈现正的环境效应。为了尽快构建健康的消落区生态系统,防止三峡库区消落区水土环境的退化,必须加强和发挥政府宏观调控职能、建立消落区土地保护区域、推广复合生态技术并做好库区污染防治与修复工作。

Environmental Effects of Interaction of Water and Soil of the Water-Level-Fluctuating Zone in the Three Gorges Reservoir

It is very weak of the eco-environment of the Water-Level-Fluctuating zone in the Three Gorges. By interacting of water and soil, weathering soil-forming of the mother rock will be accelerated, soil erosion will be aggravated, nutrient substance, such as N and P, and heavy metal will be released from soil to water greatly. In the preliminary stage of serving of the Three Gorges reservoir that make the eco-environment weaker, water and soil loss more serious, geological hazard increasing, and lead to water pollution occur, especially in the bay of reservoir where water flow slowly, the concentration of nutrient increasing, such as N and P, will stimulate alga growing rapidly, and that will give rise to the eutrophication of water. However, with healthy wet land ecosystem formed, the effect of coupling of water and soil is benefit for environment. So in order to prevent environment of Water-level-Fluctuating zone in the Three Gorges from degradation, The macro-control function of government should be reinforced, land protection zone should be established, ecological technology ,such as technology of constructed wetland, should be spreaded. At same time, pollution control and environment reconstruction should be done well.