Landscape Ecological Risk Assessment And Ecological Security Pattern Construction In The Weibei Dryland,Shaanxi

Urbanization has become one of the prominent features of China’s social development over the past half century,and high-intensity human activities have threatened the quality of the region’s ecological environment.The intensity and breadth of human activities have caused dramatic changes in the structure,function and pattern of the ecosystem,weakening the ecosystem and its ability to maintain and provide the material basis for human social development.While promoting regional socio-economic development,these behaviors rigidly constrain the ecological environment and threaten regional ecological security.How to coordinate ecological conservation and utilization in the Weibei dry plateau region of Shaanxi Province,where the conflict between human and land is prominent,is a pressing issue at present.An accurate grasp of the ecological situation of the regional landscape can effectively maintain a well-functioning ecosystem and decipher ecological and environmental problems in the study area.Based on this,this study selects five periods of land use data in the northern Weibei dry plateau area between 1980-2018 and uses land use transfer matrix,landscape ecological risk evaluation model,minimum cumulative resistance model,and gravity model to analyze land use changes,landscape ecological risk evolution,and ecological security patterns in the study area.The main research findings are as follows:(1)From 1980 to 2018,the land use structure of the study area has changed more significantly,with a decrease in the area of cultivated land,grassland and water,and an increase in the area of built-up land,forest land and unused land.The change in land use structure indicates that under the interference of external activities,especially driven by economic interests,human beings have increased the intensity of land exploitation to meet their own needs in material life.(2)During the 40 a period,the landscape pattern indices of the study area at the type scale all changed significantly,the fragmentation of the landscape increased,the stability of the landscape structure decreased,and the spatial distribution of land use plots became more and more complex.The degree of aggregation and spatial connectivity of different patch types within the study area landscape is decreasing,the overall connectivity of each landscape is decreasing,the landscape heterogeneity is increasing,and the dominance is weakening.(3)During the study period,the ecological risk in the study area generally showed an increasing trend.The frequent production and construction activities and the expansion of construction land reduced the vegetation cover and biological habitat quality,resulting in a more serious ecological risk threat in the region and a continuous increase in ecological and environmental pressure.(4)The Moran’s I values of each utilization type were higher than 0.55,and the ecological risk values were spatially positively correlated and enhanced,with obvious aggregation effects.During the study period,the Moran’s I values showed a decreasing trend,indicating that the aggregation of the spatial distribution of ecological risk values in the landscape has weakened with the time evolution,and the spatial distribution of ecological risk aggregation areas in the landscape is dominated by high-high clusters and low-low clusters,with fewer high-low clusters and low-high clusters,which are scattered and not obvious in the distribution pattern,and generally show the distribution characteristics of high in the middle and low around.(5)Seventeen ecological sources were identified,with uneven spatial distribution,mainly concentrated in relatively high altitude mountain areas.83 ecological corridors were identified.The identification of ecological corridors is of great significance for restoring the service function of ecosystem.Eighty-seven ecological nodes were identified and grade 5 ecological buffers were constructed based on accumulated resistance values.The identification of buffers and nodes plays an important role in maintaining and improving regional ecological security.According to the results of landscape ecological security pattern construction,the optimization strategy of ecological security pattern was put forward,including strict protection of ecological source area,strengthening the zoning protection of ecological buffer zone,strengthening the construction of ecological corridor and improving the function of ecological node.