Identification And Ecological Function Regionalization Of Urban Fringe Areas In Ganzhou District

In the process of urbanization,the urban fringe area represents the most dynamic and ecologically sensitive zone,encompassing a wealth of human activities and natural evolution.Ecosystem services constitute a crucial factor in the development of these peripheral areas,offering not only diverse ecosystem services to cities but also cultural services to urban inhabitants.By evaluating the value of ecosystem services(ESV)and delimiting the ecological function zones within these unique urban fringe areas,a comprehensive analysis of the region’s ecological environment and urban expansion can be conducted to identify ecological issues and propose appropriate development strategies.As Zhangye City undergoes rapid urbanization and implements relevant ecological and environmental policies,its urban space expansion and significant changes in the ecological environment become increasingly evident.Investigating the ESV and ecological function regionalization in the urban fringe area of Ganzhou District in Zhangye City contributes to a deeper understanding of local urban expansion and ecological security transformations,ultimately promoting the harmonious development of human-environment relations.Utilizing impervious surface and Point of Interest(POI)data as primary data sources,the inner and outer boundaries of the urban fringe area in Ganzhou District are delineated employing the Canny fringe detection method and sliding t detection method.Subsequently,the ESV within the study area is calculated using the modified equivalent factor method,with an analysis conducted on its spatial correlation and spatial agglomeration.The regional ecological functional units are partitioned based on the spatial characteristics,and by the actual situation of the study area,scientifically sound and rational planning and development suggestions are formulated.The main findings are as follows:(1)Employing the impervious surface index and POI density,the Canny edge detection method and sliding t detection method prove to be reasonable and effective approaches for identifying the inner and outer boundaries of the urban fringe area,respectively.This study determines the spatial extent of the urban fringe area in Ganzhou District based on POI density and impervious surface index,utilizing the Canny edge detection method and sliding t detection method.The results are verified and confirmed through site selection field verification and landscape pattern index analysis,thereby substantiating the effectiveness and scientific validity of the method employed in identifying the spatial extent of the urban fringe area in this research.(2)Examining the spatial extent of the urban fringe area in Ganzhou District,the area encompasses 297.6 km~2,accounting for 8% of the district’s total area.Its primary form is a circular distribution surrounding the urban core area,with varying widths and sizes,conforming to the distribution pattern of “urban core area-urban fringe area-rural area”.In terms of land use structure,the area exhibits diverse land use types,primarily consisting of construction land,water bodies,forest land,and cultivated land.(3)Considering the time series changes in ESV within the study area,the total value in 2005 was 664,048.95 million yuan,with the per unit area value of ecosystem services amounting to approximately 18,138.46 yuan/hm~2.In 2020,the total value reached 689,720.95 million yuan,and the per unit area value of ecosystem services for forest land was 18,839.69 yuan/hm~2.Over the 20 years,the total value increased by 256.72 million,and the per-unit area value exhibited an upward trend.The magnitude of the ecological services’ contributions experienced relatively minor fluctuations from year to year.(4)From the perspective of the spatial distribution of ESV in the study area,the ESV patterns in both 2005 and 2020 exhibited a spatially clustered distribution,with local aggregation as the primary characteristic,signifying significant spatial autocorrelation.The ESV hotspots within the study area were predominantly located in the Heihe River Basin in the west and the National Wetland Park in the northern suburbs,primarily in townships with extensive wetland areas such as Xindun Town and Sanzha Town.Moreover,hotspot areas were also concentrated at the intersections of various townships and towns,including the junctions of Wujiang Town and Xindun Town,Mingyong Town and Wujiang Town,as well as Ganjun Town and Mingyong Town.Cold spots were mainly found in Nanjie Street,Chang’an Town,and Liangjiadun Town.(5)Using the 2020 ESV as a reference,this paper divides regional ecological functional units based on the distribution of ESV cold and hot spots and the spatial distribution of Moran’s I index within the study area.The regionalization results are appropriately adjusted,taking into account the ecological environment quality,land use types,and ESV supply,support,regulation,and cultural services in the study area.The research is divided into urban construction and development zone,agriculture and low-carbon industry coordination area,nature reserve area,ecotourism coordination area,and ecological protection and water conservation area.