Assessment Of Ecological Risk In Mountainous Areas Based On Basin Landscape Structure At County Level

This research selected Qixia City,Shandong Province,an intensive mountain farming area,as the research area,which was of great value to enrich and deepen the ecological risk assessment of landscape pattern in mountain area.Using the four phase remote sensing image data of the study area in 1987?1997?2015 and 2006,the landscape pattern change information of the study area was obtained and the landscape pattern status of the study area was analyzed.Using the hydrological analysis module,300 small river basin plots were selected as risk zones,and the landscape ecological risk index was constructed based on the landscape disturbance index and landscape vulnerability index in the landscape structure.With the aid of spatial autocorrelation analysis method in spatial statistics,the spatial distribution grades and changes of ecological risks in Qixia City were analyzed,and the driving forces of change were discussed.Corresponding risk management strategies were proposed for risk areas at all levels.After analysis,the following conclusions was drawn:(1)From 1987 to 2015,in the landscape structure of Qixia City,the types of landscape views in descending order of occupied area were in the following order:landscape,garden,cultivated land,construction land,grassland,others,waters.During these 28 years,the area of different landscape types in Qixia City had undergone certain changes.The area of woodland was greatly reduced,the area was decreased by 14895.36hm~2;the garden area has increased significantly,the area occupied was increased by 14097.96hm~2;the construction land area was increased by 7985.52hm~2;the area of cultivated land was decreased by 8048.88hm~2;the grassland area was increased by339.12hm~2;water area increased by 226.98hm~2;other land area was increased by 306hm~2.(2)The ecological risk of land use and the MORAN'I of the annual ecological risk of land use change in 1987?1997?2006 and 2005 were all greater than zero.That was to say,there was a certain spatial positive autocorrelation relationship in the ecological risk degree of land use in the study area.The change in ecological risk in most regions of the study area from 1987 to 2015 was not significant.The regions with significant changes were mainly concentrated in the southwestern plains of the study area,parts of the plains in the southeast and parts of the lowland hills and plains in the northeast.And the ecological risk in these regions had changed greatly,while the changes in the ecological risk in neighboring regions had also increased.(3)In general,high-risk areas were mainly located in the northeast,southwest,and parts of southeast,and the landscape types in the risk areas were mainly construction land and cultivated land.The higher-risk areas were mainly located in the northeast,southwest,and parts of southeast.The distribution was basically the same as high-risk areas.The landscape type was mainly the mixed area of cultivated land and cultivated land.The medium-risk areas were distributed in all directions and are scattered.The landscape types were mainly woodland and garden mixed areas.The lower-risk and low-risk areas were mainly located in the central mountainous region,and the landscape types were mainly woodland and gardens.(4)From 1987 to 2015,the spatial distribution of high-risk areas,higher-risk areas,middle-risk areas,lower-risk areas,and low-risk areas in the study area was greatly changed.These changes were inextricably linked to soil erosion,orchard planting,and changes in policy factors.(5)According to different ecological risk levels,different management strategies were proposed.Among them,urban development boundaries should be designated for high-risk areas and higher-risk areas,to improve the quality of urban development and strengthen the“trinity”protection of the quantity,quality,and ecology of cultivated land;the medium-risk areas should strengthen control over key forest areas,prohibit all kinds of production activities and other acts of destroying forest resources,to improve the production quality of garden orchards and plan the scope of orchards reasonably;the low-risk areas and the lower-risk areas should strengthen the protection of forest lands,limit the development of ineffective forest lands,and implement the responsibility for protection of forest lands into the work tasks of relevant functional departments.This would serve as a reference for Qixia City's ecological management decisions.