Analysis On Response Of Ecological Sensitivity To Landscape Dynamic In The Eastern Section Of Qilian Mountain

It is important to clarify the characteristics of ecological sensitivity change for the ecological management of Qilian Mountain Park National.However,the ecological sensitivity characteristics of the study area and its response characteristics to landscape dynamic change are still unclear.Therefore,based on the Landsat TM data in 2001,2009 and Landsat OLI data in 2017,and used ArcGIS,ENVI,FRAGSTATS and other software,this paper useed landscape pattern index method to construct the ecological sensitivity model to analyze the landscape dynamic change and ecological sensitivity at the patch type level and landscape level in the east section of Qilian Mountain.Through Pearson correlation analysis method,the response of ecological sensitivity to landscape dynamic change was further analyzed,in order to explore the impact of human activities on landscape dynamic change,and to provide scientific basis for the management and protection of Qilian Mountains,the control of soil erosion,and the sustainable utilization of landscape resources.The results showed that:(1)At the patch type level,grassland area and patch numbers were the largest in the whole landscape from 2001 to 2017,which was the dominant landscape component in the whole landscape,followed by bare land,shrub forest land and tree fores land,snow and water area and patch numbers were the smallest.There are differences in area,quantity and shape among landscape components.The area and patch numbers of shrub forest land were increasing,which is stable in the whole landscape.The area and patch numbers of tree forest land,water area and snow were decreasing,which is unstable and fragile in the whole landscape.The area of bare land was increasing and the patche numbers was decreasing,which is stable in the whole landscape.The area of grassland was decreasing and the patche numbers was increasing,which is unstable in the whole landscape.The shape of grassland was becoming more and more complex,while the shape of other landscape components tended to simplify.(2)On the landscape level,Shannon diversity index,Shannon evenness index,fragmentation degree and separation degree of landscape in the eastern part of Qilian Mountains increased more than decreased in 2001-2017,and increased in general.The level of landscape diversity,the degree of heterogeneity and fragmentation increased,and the landscape components were dispersed and tended to be homogeneous.(3)From 2001 to 2017,at the level of patch type,the ecological sensitivity of bare land,grassland,tree forest land,shrub forest land,water and snow was at a low level.On the landscape level,the ecological sensitivity of the eastern part of Qilian Mountains was at a low level,and on the whole,the sensitivity was increasing,and tended to develop to a moderate level.(4)At the patch type level,each landscape index had a certain impact on the ecological sensitivity.Among them,fragmentation degree and patche numbers had a greater impact on ecological sensitivity,followed by percentage of patche numbers,degree of separation,patch type area,and fractal dimension had the weakest impact on ecological sensitivity.At the landscape level,fragmentation index and segregation index had a greater impact on ecological sensitivity,followed by Shannon diversity index and Shannon evenness index.In general,the disruption of human activity was the determining factor for the change of landscape and ecological sensitivity.The results of the study had positive significance for the maintenance and sustainable development of regional landscape.