Key Area Identification Of County Ecological Restoration Based On Ecological Network

Optimizing the development pattern of territorial space and carrying out regional ecological restoration and improvement are important measures to promote the construction of ecological civilization.The identification and construction of ecological network is the basis for maintaining the ecosystem health,ensuring the ecological security,and promoting the ecological restoration.The finding of key restoration area can provide an important reference of decision-making for the systematic restoration of various elements of the land space.This paper took Jiawang District in Xuzhou City as an example.In this paper,the author identified the ecological source as well as ecological corridor,node and other elements from the perspective of contribution resilience organization and methods of the minimum cumulative resistance model.Also,the ecological network of Jiawang District is constructd,and the structural characteristics of the ecological network is evaluated by using graph theory.Further,the ecological source is identified by integrating the characteristics of complex network and community mining.The purpose of this paper is to provide a practical reference for the implementation of ecological restoration and the compilation of land space planning in Jiawang District.The conclusions are following:(1)The county ecological security evaluation was carried out,based on the contribution resilience organization.From 2008 to 2019,the average values of ecological security comprehensive index of Jiawang District were 0.36,0.38,0.36 and0.43 respectively,showing a trend of small increase first,then decrease,and then increase,and the spatial distribution characteristics of the whole county were generally similar;using standard deviation classification method.Ecological Security was divided into five levels,and the highest level(Level 1)security area accounted for about6%of Jiawang District area on average in four years;the higher level of ecological security area accounted for 6%of Jiawang District area The average area of security zone(Level 2 and level 3)accounted for 56%of the area of Jiawang District,which together constituted the base of ecological protection in Jiawang District;low level(Level 4 and level 5)ecological security zones were distributed in all towns,accounting for 38%of the area of Jiawang District,which need to be controlled by necessary measures.(2)Based on the paradigm of"source identification-resistance surface establishment corridor-construction ecological node identification",this paper studied the ecological network of Jiawang District.In 2019,the ecological source area was58.38km~2,accounting for 9.5%of the total area of the study area.The land types were mainly woodland and water area,and the spatial distribution was relatively uneven.85ecological corridors were identified,which were more in the middle and less around.267 radiation channels were identified,which were distributed in irregular branches.41ecological nodes were identified,which were mainly distributed on the ecological corridors.Through the analysis of landscape centrality and network measurement,the patches or nodes(high value area of intermediate degree)that played a key role were concentrated in the central and northern mountains of the study area,while the values ofαindex andγindex of connectivity of the ecological network were relatively small.The material and energy flow between the ecological patches in the region was hindered to some extent,so it was urgent to strengthen the protection of the elements in the ecological network.(3)The complex ecological network theory and circuit theory were applied to identify the ecological restoration area.The primary and secondary ecological blind areas identified by Tyson polygon and community mining algorithm were mainly distributed in the middle of Jiawang District.The sum of the two areas was 122.49km~2,accounting for 19.75%of the total area of the study area.The land use type is mainly construction land,and the proportion of ecological land is small.Some engineering measures need to be taken to improve the stability of ecological functions There were21 obstacle areas identified by mapper tool,most of which were located on the ecological corridor,the intersection of ecological source and ecological corridor,which were the key areas of ecological network connectivity and ecological restoration;there were 50 ecological fault points,which were concentrated in the traffic trunk line of Jiawang,whose existence would cut off the connectivity of ecological network;there were comprehensive ecological restoration fault points,ecological restoration obstacle areas and ecological restoration areas Jiawang ecological restoration area was obtained,and the corresponding restoration measures were put forward.