Research On Identification And Configuration Of Green Infrastructure Nodes In Resource-based Cities

The development of resource-based cities is closely related to the exploitation and processing of mineral resources,which is characterized by the high-intensity exploitation and utilization of the land and the strong disturbance to the ecological environment.Compared with ordinary cities,the ecological protection of resource-based cities is more urgent.Green infrastructure provides a strategic guiding framework for coordinating the relationship between economic development and environmental protection.Among them,as one of the components of the green infrastructure network,the ecological node has the characteristics of key location and small scale,which is worthy of priority in the context of the contradiction between urban land supply and demand.From this point of view,this paper chooses Wu’an,a typical mining city,as the research object,and focuses on solving the problem of location,scale and shape of ecological nodes in order to provide reference for the construction of ecological civilization in resource-based cities.The specific conclusions of this study are as follows:(1)combining the minimum cumulative resistance model with the spatial analysis technology of GIS,this paper selects forest land,grassland,unused land and water area with an area larger than 50hm~2 as the ecological source,and then 86ecological corridors are generated by superimposing four types of landscape resistance factors:land use type,distance from mineral resources,elevation and slope.Extract the intersections of ecological corridor,the intersections of ecological corridor and"ridge line"of landscape resistance which have a total of 92 as the ecological nodes.According to whether the land use status of ecological nodes is ecological land,they are divided into two types:current ecological nodes and potential ecological nodes,and the hotspot analysis method is used to determine the important levels of different ecological nodes.(2)in order to ensure the scientific rationality of ecological construction scale,the area threshold of nodes is studied.Based on the location recognition results of green infrastructure nodes,four landscape connectivity indices of NC,IIC,PC and dPC are selected.By analyzing the changes of different landscape connectivity indexes under the nine distance thresholds from 50m to 1400m,it is found that when the distance between patches is 400m,the landscape connectivity is significantly promoted.Under the distance threshold of 400m,this paper focuses on the correlation between the ecological patch area and its important value index in Wu’an green infrastructure network,and finally determines 16hm~2 as the optimal area threshold for ecological node construction in Wu’an City.(3)Considering that the nodes have good characteristics of ecological flow agglomeration,the circular shape is selected as the main configuration of the potential node ecological construction,and then the overall layout of the optimization of the green infrastructure network in Wu’an City is formed.From the two aspects of green infrastructure network scale and study area scale to test the optimization effect of ecological node,it is concluded that ecological node optimization has positive significance in strengthening the connectivity of green infrastructure networks,reducing the ecological resistance of key locations in green infrastructure networks,and improving the value of ecosystem services in Wu’an.Finally,based on the previous research results,this paper puts forward practical suggestions for effective ecological construction activities in Wu’an City.