Study On The Evaluation Of Sustainable Development Of The Ecological Wetlands Detention Basin In Nansihu Lake

Nansihu Lake detention basin plays an important role in flood control of Huaihe riverbasin, which has lower operation standard, unstable production and living environment and lowspeed of economic development. At the same time, the area of wetlands in Nansihu Lake basinis reducing year by year. In contrast, the area of coal mining subsidence land is increasing,which makes the ecological environment fragile. With the contradiction between theapplication and development of detention basin intensifying, the discussion of the reasonabledevelopment mode for detention basin becomes significant. In order to evaluate the degree ofsustainable development of Nansihu Lake detention basin, the evaluation index system wasestablished. This paper also put forward the corresponding improvement countermeasure tosolve the problems that influence the degree of sustainable development of Nansihu Lakedetention basin. In addition, this paper presents a sustainable development mode which iscombined of the construction of detention basin, ecological wetlands, and government of thecoal mining subsidence land under the guidance of flood resource utilization thought. Theunique construction mode of ecological wetlands detention basin for Nansihu Lake has vitalsignificance to both improving the ecological environment of Nansihu Lake and relievingwater resources shortage. The conclusions are as follows:(1) Based on the theories of composite, this paper established the composite system ofdetention basin and the evaluation index system for sustainable development of Nansihu Lakedetention basin. The evaluation index system was made up of six indicators including floodcontrol, society, economic, environment, resource, and population to establish. The weight ofindicators is calculated with analytical hierarchy process (AHP). In addition, the fuzzyaggregate analysis method was applied to calculate the degree of sustainable development ofNansihu Lake detention basin. It is shown that the degree of membership of sustainabledevelopment for the three sections, including Si River～Qing Mountain, Jie River～ChengguoRiver, Xinxue River～Xi Mountain, are all below0.7. All of them are in a basically sustainablestate.(2) Risk zoning was studied by using the methods of empirical formula and numerical calculation. The flood risk degree was used as an important indicator of the evaluation indexsystem for sustainable development. It is shown that the light risk area is167.06km2, makingup64.6%of the total flood detention area, and its population is7.65ten thousand.(3) According to the results of evaluation, the factors that influence the degree ofsustainable development of Nansihu Lake detention basin were found out and thecorresponding improvement countermeasures were put forward. The measures includecontrolling the growth of the population, adjusting the internal structure, promoting theadjustment of industrial structure and paying attention to ecological environmental protection.A refuge construction plan is also prepared based on the risk zoning.(4) This paper presents a thought of using flood water to recovery wetlands in proper timeand governing the coal mining subsidence land in terms of the characteristics of ecologicalwetlands detention basin. The aims of the sustainable development mode which is called“flood control-society-ecology-economy” were to protect ecological wetlands, govern thecoal mining subsidence land, construct detention basins and promote the standard of floodcontrol.