Research On Urban Ecological Network Optimization Based On Structure And Function Coupling

Rapid urbanization brings opportunities to cities,but it also faces enormous challenges.With the continuous expansion of urban construction land,it leads to a series of problems such as fragmentation of urban ecological space layout,obvious heat island effect,severe haze and so on,which brings severe challenges to biodiversity protection and improvement of human settlements environment.This paper aims to propose an optimization framework of urban ecological network from the perspective of the coupling of structure and function,to make up for the shortcomings of previous scholars’ construction of ecological network with structure as the goal.Taking Hefei urban area as the research area,on the basis of the land use data obtained by ENVI,using ArcGIS,Fragstats,Guidos,Conefor and Phoenics software to carry out spatial analysis,landscape pattern index analysis,morphological spatial pattern analysis,landscape connectivity index quantitative evaluation index calculation and Urban Ventilation corridor simulation,according to analysis and simulation.Evaluate and optimize the structure and function of the current ecological network.On the basis of the optimization of the structure and function of the urban ecological network,the coupling of the structure and function of the ecological network is realized with the support of ArcGIS platform,and then the optimization results of the urban ecological network based on the coupling of structure and function are obtained,so as to achieve the goal of maintaining the stable development of the overall urban ecological environment and improving the human settlements environment.The main conclusions are as follows:(1)The urban ecological network optimization framework based on the coupling of structure and function is constructed.Firstly,based on the urban ecological network structure and function evaluation,the urban ecological network structure and function are optimized.Finally,the coupling structure and function get the optimization results of urban ecological network,and propose ecological network planning and implementation.(2)In the evaluation of the current ecological network structure in Hefei City,due to the simple rules of the current ecological patch shape,the contact area with other types of land is small,resulting in low anti-interference and poor contact with the outside world.The degree of connectivity between the grounds makes up for its shortcomings.The current ecological corridors are mainly divided into water corridors and green corridors.The number of green corridors is small and the distribution is seriously unbalanced,mainly showing the state of low north and south and east and west.Moreover,there is a clear difference in the degree of connection of ecological corridors.For areas with strong connectivity,the development trend should be maintained.For areas with poor connectivity,corresponding optimization measures should be formulated according to the actual development of the region to improve the ecological corridor.Road connection degree.In the optimization of ecological network structure in Hefei City,the ecological network structure was optimized from three aspects: selecting ecological plaques with higher connectivity as ecological source,constructing multi-level ecological corridors and classifying the importance level of ecological nodes.(3)Based on the evaluation of the current ecological network function in Hefei City,based on the quantitative assessment of the three ecological network functions of mitigating urban thermal environment,reducing air pollution and improving urban wind environment,the ecological network function of Hefei research area is strong.It is divided into seven levels: strong,strong,strong,medium,weak,weak,and extremely weak.Its spatial distribution shows significant regional differences,forming a spatial distribution characteristic of the weak central periphery.In the optimization of ecological network function in Hefei City,from the aspect of ecological network function zoning control,the ecological network functional protection zone,functional protection and improvement zone,functional improvement zone,proposed repair zone,and the most needed repair zone species functional division are formed.In the ventilation corridor,four first-class ventilation corridors and six secondary ventilation corridors are constructed.(4)Based on the ecological network optimization results of structural and functional coupling,the ecological patches are divided into three grades,which are first-level integrated ecological patches,secondary integrated ecological patches and tertiary integrated ecological patches,and the ecological corridors are divided into one level.The integrated ecological corridor,the second-level integrated ecological corridor and the three-level integrated ecological corridor,the ecological nodes are divided into a first-level integrated ecological node,a second-level integrated ecological node and a three-level integrated ecological node.And from the delineation of ecological network planning structure,the structure form of “two rings and two wedges and multiple corridors” has been formed.The ecological network space is divided into ecological bottom line area and ecological development area from the aspect of ecological network control division,and finally divided according to ecological control area.Coupling results with ecological networks,deepening and improving the planning and construction guidelines for ecological patches,ecological corridors and ecological nodes.