Research On Evaluation Method Of Redundancy Structure Importance Of Urban Ecological Network

Under the background of ecological civilization,China is in the key stage of the reform of spatial governance system,which needs to solve the spatial coordination problems of ecology,agriculture and urban construction,which requires each spatial system has a clear hierarchical structure.Among them,reasonable urban ecological space is the necessary support to realize healthy life.The construction of ecological network is the basis of current ecological space planning.The construction methods of ecological network are mostly seeking the optimal solution,and lack of the definition of structure grade.The hierarchical delimitation method for the main structure of urban ecological network needs further study.According to hierarchy theory,redundancy theory,the urban ecological network should include two parts: backbone structure and redundant structure.In this study,Hegang is taken as an example,this study includes two parts: urban ecological network redundancy structure identification and ecological network redundancy structure importance evaluation:(1)Identifying the urban ecological network,The provincial backbone network extraction method based on edge betweenness is used to extract the backbone structure of the ecological network within the city area,so as to identify the redundant structure of the city area.(2)The importance evaluation of ecological network redundancy structure is the key research content,and the ecological network redundancy node is proposed Evaluation method of construction importance: 1)evaluation factor screening: Taking "patch as the evaluation subject,function oriented and building a hierarchical evaluation system" as the screening principle,the patch type,area,shape,overall connection importance,ecosystem service value and surrounding land use impact are selected from three levels of urban ecological patch,urban ecological network and urban land space.From the functional point of view,screening evaluation indicators and constructing evaluation system;2)the evaluation factor calculation: Taking Hegang as an example,the quantitative calculation of each index is carried out,and the importance analysis is carried out by using the AHP combined with expert opinions;3)the grading of evaluation results: the redundant corridor structure is given the same importance as its related source ecological patches,and integrating the evaluation results.The natural breakpoint method is selected to grade the evaluation results,fully reflecting the characteristics of the data itselfThe application of evaluation results of urban ecological network redundancy structure in urban land spatial planning is considered.According to the goal of ecological space construction in Hegang,the corresponding width is given to the redundant corridor,and the redundant structure of ecological network with hierarchical level is integrated with the backbone structure.Due to the irreplaceable characteristics of backbone network,it is given the highest importance level,so as to clarify the structural grade of urban ecological network.The evaluation results make up for the deficiency of the "double evaluation" results which cannot clearly define the urban ecological space hierarchical structure,but also provide more abundant ecological space on the basis of ecological red line to meet the growing demand for ecosystem services.The urban ecological network with reasonable structure level provides the basis for the effective coordination of urban land ecological space,agricultural space and urban construction space.