Study On Habitat Restoration Design Of Polder Lake

Under the special conditions of large freshwater lakes with more people and less land,there are basically polder areas around the large freshwater lakes in China.The reclamation has invaded the free surface of the lake in a large area,changed the structure of the lake edge and bottom,and seriously affected the habitat.In recent years,the polder restoration project has been the focus of ecological environment construction of large lakes and has achieved favorable results.However,there are few studies on the specificity of the follow-up habitat restoration of polder lakes.Taking back also lake landscape design is the process of the topography,space,basal reshaping,need to have a certain direction,in the design of this paper is intended to explore a suitable for taking back the lake also this kind of site design methodology of regional reconstruction,made by lakes serious human impact such as reclamation and degradation of ecosystem to regain stability,healthy ecological structure.Based on the induction of lake habitat quality evaluation research and complement,built for taking back those kind of lake habitat quality evaluation system,chose to benefit from the Angle of landscape put forward the corresponding repair strategy evaluation indexes,through the evaluation system for the reclaimed lake environment system structure,function,a quantitative assessment and study law,missing link and it can clarify the influence of human disturbance on the polder lake,then translate the basic law into the basis of planning and design.The target layer of the constructed system is the Lake Habitat Quality Assessment Index(LHQ),and the criterion layer includes five types of indicators: lakeside zone status,lake shoreline morphology,lake hydrodynamics,lake water quality,and lake organisms.These five types of indicators reflect the habitat quality from three directions of physical structure characteristics,hydrological characteristics,and biological characteristics,respectively.This system was applied to Gucheng Lake,and the evaluation results showed that the quality of the habitat was poor(LHQ=36),which needed to be restored to a large extent.The results were most affected by the status of the lakeside zone,the lake shoreline and the biodiversity of the lake.Based on this,paper studied the design of the restoration of the habitat in Gucheng Lake.After that,the steps and methods of lake habitat restoration were proposed according to the evaluation results and current situation analysis.Firstly,through the construction and analysis of the lake food web model,appropriate indicator species were selected and the habitat factors of indicator species were analyzed,and habitat remodeling was carried out according to the habitat requirements of species.The reconstruction steps include the spatial layout of habitat,the construction of environmental base,the construction of hydrodynamic conditions and phytocenosis,and the specific strategies of ecological island chain and shallow water replenishment are put forward.The innovation point of this research lies in constructing an index system of the badly damaged type of lake to reflect on the impact of human activities on lake habitat evaluation system,on the basis of previous research,with lakeside with natural rate,fractal dimension(FD),and other quantitative evaluation index instead of subjective descriptive index to evaluate physical structure and hydrological conditions,improve the objectivity of the evaluation and scientific,then put forward the repair strategy.After the design,the same evaluation system was used to predict the habitat quality of Gucheng Lake,and the results showed that the overall habitat quality of Gucheng Lake could reach a good grade(LHQ=55).