Study On Land Use Landscape Ecological Security Assessment And Ecological Security Pattern Construction In Nanchang City

With the accelerating urbanization process,a series of urban common diseases have emerged one after another,such as environmental pollution,resource shortage,and land use contradictions,and urban ecological environment problems have become increasingly prominent.How to coordinate regional ecological security in the process of rapid urbanization is a realistic problem and that needs to be solved urgently.At the same time,urbanization,as an important driving force for land use and land cover change,has profoundly affected the landscape pattern of the region.Therefore,conduct regional ecological security assessment and ecological security pattern construction from the perspective of landscape is of great significance for regulating the spatial pattern of Nanchang City,optimizing the utilization of regional land resources,and ensuring the sustainable development of the region.This paper takes Nanchang city of Jiangxi province as the research area,based on the remote sensing image data of 2000-2017,as well as the road network and DEM data,this paper analysis the evolution of the landscape pattern in Nanchang first,then the landscape ecological security evaluation model was constructed in four aspects:structure,landscape vitality,landscape pressure and landscape function.The spatial and temporal changes of landscape ecological security in Nanchang City were explored by using geostatistics and spatial correlation analysis,and the spatial pattern of morphology was analyzed.The MSPA method and the minimum resistance model constructed the ecological security pattern of Nanchang City.The results showed as follows:(1)The landscape types of Nanchang City are mainly cultivated land,woodland and waters.Between 2000 and 2017,the area of cultivated land in Nanchang continued to decrease,with a total reduction of 80018.72 hm~2.The area of construction land increased year by year,with a total increase of 78843.51 hm~2.The area of woodland,grassland,waters and other landscape types fluctuated to varying degrees during different periods of the study period.The landscape type transfer matrix indicates that the landscape outflow is dominated by cultivated land,forest land and water area,and the landscape inflow is mainly cultivated land,forest land,water area and construction land.The landscape pattern index analysis shows that the landscape patch density,edge density value and diversity index and fragrance uniformity index of the study area are increasing continuously,and the spread index and the aggregation index are continuously decreasing,and the degree of landscape fragmentation is increasing.(2)The results of geostatistical analysis show that the optimal models of landscape ecological security index of Nanchang City from 2000 to 2017 are fit spherical models,and the ratio of gold to abutment is about 25%.The landscape ecological security index has strong spatial autocorrelation.The landscape ecological security level in each period of Nanchang City is generally represented by the spatial pattern of low ecological security value in the central area and high ecological security value.Part of the reduction in landscape ecological security values is concentrated in the central region and the degree of aggregation is increasing,showing a deteriorating trend.The results of spatial autocorrelation analysis show that the regional landscape ecological security level of Nanchang City has a high positive spatial correlation during the study period,and the high value-high value area and the low value-low value area clustering of the landscape ecological safety index of Nanchang City in each period.It is very prominent,the low-high or high-low out of group"singular point"is relatively small,and the distribution pattern of agglomeration space is more obvious.The distribution of high value-high value area,low value-low value area and the distribution of landscape ecological security are basically consistent.(3)The results of landscape ecological security evaluation show that the landscape ecological security status of Nanchang City has deteriorated from 2000 to 2017,and the coefficient of variation of landscape ecological security index has been increasing continuously,and the heterogeneity of spatial ecological security has been increasing.During the period,the landscape ecological security pattern of Nanchang City was mainly changed:the proportion of high-security area was basically unchanged,the proportion of medium-high safety area was decreasing,and the proportion of medium-sized safety zone,medium-low safety zone and low-security zone keep growing.The high-security zone and the higher-security zone are mainly distributed in the Wanli District,the northern part of Anyi County,the lower western part,the southeastern part of Jinxian County,and the area adjacent to the Poyang Lake in the newly built north.The middle and low security areas are mainly located adjacent to the main city.The new north,the new south and the south of Nanchang County,the low security zone is located in the main urban area,and most of the areas are in the moderate security zone.(4)Based on the morphological spatial pattern analysis method and the results of landscape connectivity evaluation,and considering the forest parks and nature reserves with significant ecological service functions and rich biodiversity in Nanchang,12ecological sources are determined,and the total area accounts for 16.80%of the total land area.Through the minimum cumulative resistance model,18 potential corridors and 18ecological nodes in the study area were identified,and the ecological security pattern of Nanchang City was constructed.Based on this,the ecological security pattern was constructed from ecological source protection,ecological network optimization,and ecological node strengthening.The countermeasures and suggestions were put forward.