Evaluation And Simulation Of Ecological Vulnerability In Mountainous Counties Of The Northeast Hebei Province

In recent years,with the swift growth of the population and the deepening of land use,the disturbance and destruction of the ecological environment become increasingly fierce,.The carrying capacity of ecosystems is gradually weakened,and the ecological vulnerability is constantly enhanced.The research on ecological vulnerability gets widespread attention of scientists and international organizations.The paper constructed the framework of ecological vulnerability evaluation and simulation of mountainous counties in northeast of Hebei Province based on the VSD model,and then took Qinglong Manchu Autonomous County as the research area to make an empirical research.By evaluating the ecological vulnerability of the study area in 2002,2009 and 2015,exploring the impact of land use change on ecological vulnerability,simulating different scenarios of ecological vulnerability,the study aimed to reveal the status and evolution of the ecological vulnerability in Qinglong Manchu Autonomous County.Then the methods and strategies for reducing ecological vulnerability were proposed,in order to provide reference for the protection of ecological environment in the study area.The conclusions obtained in this paper as follows:(1)The ecological environment in the research area developed during the study period,but the status was still not sanguine.The western,northern,central and the south-central parts of the county were important areas for ecological protection and restoration.Meanwhile,ecological protection in the northeast part of the county should be strengthened.The averages of ecological vulnerability index of Qinglong Manchu Autonomous County in the three time points was 0.3944,0.3827 and 0.3794 and showed a gradually decreasing trend.Simultaneously,the area of high and severe vulnerable areas dropped sharply while the slight vulnerable areas increased significantly,which illustrated that the environment was developing with a good trend.But in 2015,the ecological vulnerability of most region was still serious,so the circumstances was still severe.The ecological vulnerability washigh in the northern,western,central and south-central areas,and that was low in the eastern and southwestern areas.The centroid of the severe vulnerable area was locateded in the northwest of the county in 2015.Therefore,the above-mentioned areas were still important areas for ecological protection and restoration.Within the period of the research,the vulnerability of the western and northern regions showed a decreasing trend,but that of the northeast region increased,and the ecological vulnerability centroid of the research area shifted to the northeast,so the ecological protection in northeast of the county should be strengthened.(2)Ecological vulnerability was significantly affected by land use changes.To reduce the ecological vulnerability,exploiting unused land reasonably,preventing farmland abandoned behavior and limiting the unrestricted expansion of construction land,were effective ways in the study area.Within the period of research,the ecological vulnerability remained unchanged in areas where land use types had not changed,except for the unused land.The ecological vulnerability changed significantly in areas where land use types had changed.In above areas,the conversion of other land to woodland could decrease the ecological vulnerability,while the conversion of other land to construction land or unused land could significantly enhance the ecological vulnerability.The destruction of woodland and the expansion of construction land had led to the improvement of ecological vulnerability,while the exploitation of unused land and the large-scale afforestation were the important reasons for the reduction of ecological vulnerability in the study area.(3)The different scenarios of ecological vulnerability based on the OWA algorithm simulation could provide reference for the development strategy formulation of different stages.By simulating the ecological vulnerability status in different situations,we could see that the degree of ecological vulnerability in the study area gradually improved,and the ecological environment developed with a worsening trend.On this basis,based on the rational risk interval [0.8,1.2],this study predicted the ecological vulnerability scenarios under three policy orientations,i.e.economic priority,maintaining the status quo and ecological priority,in order to provide a comprehensive decision-making reference for the development strategy of the research area.This study can provide reference for the research of the ecological vulnerability of mountainous counties in the northeast of Hebei Province.It can also provides basis for the protection of ecological environment and the construction of early warning mechanism of ecological security in Qinglong Manchu Autonomous County.