Ecological Risk Evaluation Study Of Harbin City Landscape Based On Land Use Change

China’s urbanization process is accelerating,leading to a high-speed development of social economy to bring urbanization and industrialization at the same time,land use is subject to unreasonable human activities leading to frequent natural environment,which seriously threatens the production and life of human beings.With the continuous development of geographic information technology,ecological risk research based on landscape ecology has become a research hotspot in academia.Landscape ecological risk evaluation uses landscape pattern index to establish the correlation between landscape structure and ecological processes to evaluate the characteristics of landscape ecological risk changes in the region,so as to reflect the impact of human activities on the ecological environment.Therefore,landscape ecological risk assessment based on land use change provides an important basis for land use management and related policy formulation,and is of great practical significance for protecting the ecological environment and achieving sustainable use of resources.This paper takes Harbin city as the research area,and analyzes the land use and landscape pattern changes based on land use data in 2000,2010 and 2020;on this basis,we use GIS and RS to construct a landscape ecological risk index from the perspective of landscape pattern,analyze the change characteristics of landscape ecological risk in Harbin city,and use geographic probes to explore the dynamic changes of landscape ecological risk in Harbin city The main driving forces of the change in landscape ecological risk in Harbin City were investigated by using geographic probes.The main research contents and conclusions of the paper are as follows:(1)From 2000 to 2020,each land use type has undergone large changes.The area of arable land showed a decreasing trend,decreasing by 1320.41 km~2,while the areas of forest land,grassland,water bodies,construction land and unused land showed an increasing trend,increasing by 172.33 km~2,70.47 km~2,372.68 km~2,688.03 km~2,and16.94 km~2,respectively,among which arable land and forest land were always the dominant land use types in Harbin City.Among the single dynamic attitude,the fastest rate of change of construction land is 45.49%,and the rate of change of comprehensive dynamic attitude keeps increasing up to 0.26%.The main forms of land use change in Harbin City are the transfer out of arable land area and the transfer in of construction land area.In the spatial analysis of the landscape pattern,all indices show more significant change characteristics,indicating that there is a significant correlation between land use change and ecological effect.(2)Based on the method of landscape pattern,according to the theory of landscape ecology,landscape indices such as landscape disturbance degree,landscape fragility degree and landscape loss degree were selected to construct the landscape ecological risk evaluation model and analyze the dynamic evolution characteristics of landscape ecological risk in Harbin.The results show that the spatial distribution of landscape ecological risk level in Harbin City from 2000 to 2020 is higher in the west than in the east,and higher in the north than in the south,and the overall level of medium risk level,and the risk index is gradually increasing,with an increase of 4.3%.The area of high and higher ecological risk areas shows a trend of first decreasing and then increasing,the area of medium ecological risk areas increases year by year,and the area of low and lower ecological risk areas keeps decreasing,among which the area of medium ecological risk areas increases by 1465.82km~2,and the area of low ecological risk areas decreases by 889.89km~2,the transfer rate of each ecological risk level,the transfer rate of lower and low is larger,the transfer rate of high and higher increases year by year The transfer rate of each ecological risk level is higher for lower and lower transfer rates,and higher and higher transfer rates increase year by year,and the transfer rate to medium risk areas is the fastest.In summary,the ecological environmental protection work in Harbin City has been effective,and the environmental quality has improved and is in a positive development trend.(3)Based on the geographic detector,the main factors influencing the dynamic change of ecological risk in Harbin landscape were quantitatively analyzed by the factor and interaction detectors;the results of the factor detector showed that the explanatory power of elevation and year-end population on the dynamic change of ecological risk were 2.3%and 2.0%,respectively,which had significant explanatory power on ecological risk;the results of the interaction detector showed that various factors influenced the dynamic change of ecological risk after interacting with the elevation The results of the interaction detector showed that the explanatory power of all factors on the dynamic changes of ecological risk was greatly improved after interacting with the elevation factor.The interaction between elevation and topographic factors is the main driver of ecological risk dynamics in the Harbin landscape.