The Assessment Of Land Use Landscape Ecological Risk And Construction Of Ecological Security Pattern In Qinglong Manchu Autonomous County

The health and stability of natural ecosystems is the foundation of the sustainable development of human civilization,and it is also the key of the survival and reproduction of all kinds of organisms on the earth.There is no doubt that the rapid development of social economy has brought industrialization and urbanization to the mankind.However,it also has brought great impact to the natural ecosystem because of its change in the structure of land use.This impact has caused the emergence of ecological risk.So how to scientifically evaluate risk,management risk,and build an ecological security pattern in the region has become an important subject in the current academic field.Therefore,this paper took the slow-change landscape as the breakthrough point,taking the national key ecological function area,Qinglong Manchu Autonomous County as the research area,and starting from the explicit and recessive two aspects of the landscape ecological risk itself.It selected the different factors as the evaluation index,and constructed the evaluation index system of the landscape ecological risk.Combined with GIS,Geoda and other spatial analysis techniques,landscape ecological risk assessment and spatial correlation analysis were carried out to reveal the temporal and spatial variation pattern of risk pattern.Then,taking the landscape ecological risk index of the research area as one of the resistance factors,and using the MCR model to establish the cost distance surface so as to distinguish the ecological security components.What is more,the paper also use the gravity model to distinguish the importance grade of the ecological corridor.Finally,the optimized ecological security network pattern was obtained.The summing-ups are as below:(1)From the perspective of land use and landscape pattern,the change characteristics of landscape pattern in the study area were analyzed.In 2000-2014,the matrix landscape in the study areas were composed of woodland and unused land,accounting for more than 65% of the total area.The total landscape area showed a trend of "three increasing and three decreasing",that is,the area of construction,forest and garden increased,and the area of farming,water and area decreased.During the study period,the number of landscape patches increased and fragmentation increased,besides,the shapes of patches were more irregular.The separation degree of homogeneous landscape patches increased as a whole,and the connectivity of the same type landscape decreased.The dominance of woodland increased year by year,but the dominance of most land use landscape types decreased.The landscape heterogeneity increased year by year,and landscape diversification tended to be more obvious.It showed that the interference of human activities to the research area was increasing year by year,and the landscape structure of the study area was becoming more and more complicated.(2)Through the landscape ecological risk assessment,the temporal and spatial variation of Qinglong Manchu Autonomous County's risk and its spatial correlation were obtained.By drawing on the classification of knowledge management,the cognition of "risk" was divided into two types,"the hidden risk" and "the dominant risk",and the evaluation index system was constructed by selecting relevant index,thus the change law of landscape ecological risk in the study area was obtained.The results showed that the overall level of landscape ecological risk was the common effect of the dominant and the hidden risks.In view of its temporal and spatial variation,the regional distribution of high risk grade gradually has become smaller and has a continuous trend,but the overall risk of the county was still high,and the landscape ecological risk value of the western county was higher than that of the eastern region.According to the global spatial auto-correlation results,the risk values in the study area had a higher spatial positive correlation,and the adjacent plots had a strong aggregation distribution in the space,and the HH clustering and the LL clustering showed an enhanced trend during the study.According to the auto-correlation results of local space,it was found that the value of landscape ecological risk in the study area was mainly based on HH clustering and LL clustering,and other clusters were scattered,and showed a characteristic of "high in the middle while low on the all side".(3)It established a landscape ecological security pattern in Qinglong Manchu Autonomous County,and gave pertinent countermeasures and suggestions for different functional areas.By identifying the ecological source areas of the study area,and combining the actual selection of resistance factors in the study area,the ecological safety pattern was constructed based on the minimum cumulative resistance model.According to the gravity model,the relative importance of the ecological corridors was distinguished,and the first or the second level corridors were obtained.The natural break point method was used to divide the cost distance of the construction.Finally,the study areas were divided into 5functional areas: ecological source,buffer zone,low resistance area,middle resistance area and high resistance area,and the countermeasures and suggestions for ecological safety were put forward.The purpose of this study was to provide a theoretical basis for the future ecologicalplanning of the study area so it could develop a continuous and stable role of the national key ecological function areas.