Study On Land Use Change Scenario Simulation And Spatiotemporal Response Of Ecological Risk In Guangzhou

In recent years,with the acceleration of urbanization and industrialization,China’s socio-economic has developed rapidly.The accumulation of various production factors,the increasing demand for urban construction land,and the scarcity of land resources promotes the transformation in the pattern and extent of land use.Land use change is closely related to the ecological environment and can be directly reflected in the regional landscape pattern,which has a certain impact on the organizational structure of the ecosystem.Therefore,under the background of national ecological civilization development goal and new urbanization development strategy,this paper discusses the risk degree caused by regional land use change to the ecosystem,simulates the future land use evolution trend,grasps the development state of regional ecological risk,and Then rationally allocates land resources and optimizes the spatial pattern of urban production,living and ecology.Taking Guangzhou as an example,this paper selects the remote sensing images in 2001,2009 and 2017 for interpretation,and obtains the land use classification data in three periods.Using the land use area change,land use transfer matrix and comprehensive index of land use degree to quantitatively analyze the land use evolution law of Guangzhou from 2001 to 2017.Then,from the perspective of landscape pattern,the ecological risk index model is constructed by coupling the landscape loss index and ecological risk intensity parameters,and the land use ecological risk level and its spatial-temporal differentiation characteristics are measured and analyzed.In addition,based on the FLUS model,the spatial distribution of land use in 2025 is simulated and predicted for the natural development scenario and the"three-line"constraint scenario;and the response of landscape ecological risk is studied for the simulation results to compare and analyze the changes of ecological risk with the two scenarios.The main results are as follows:(1)The land use in Guangzhou is mainly forest land,cultivated land and construction land.During 2001-2017,only construction land increased in all types of land use,while other land use types decreased,of which the transfer out area of cultivated land is the largest,and the main flow direction is construction land.It can be seen that the rapid expansion of construction land is the most prominent feature of land use change during the study period.In addition,the degree of land use in Guangzhou is gradually deepening.Panyu District,Baiyun District,Huangpu District and Huadu District have the most dramatic changes in the degree of land use,which is in the period of rapid development.(2)From 2001 to 2017,the ecological risk index of land use in Guangzhou showed a rising trend.From the perspective of spatial differentiation,the landscape ecological risk level of Guangzhou decreases from the central city to the periphery,presenting a circle layer layout.Among them,the areas with lower and low ecological risk are larger and tend to expand,mainly distributed in the dense forest land in the northeast and waters in the southern of the study area.The medium ecological risk areas are located in the transition zone between the low ecological risk areas and the high ecological risk areas,and the cultivated land and waters are concentrated.While the areas with higher and high ecological risk are smaller and tend to increase,mainly distributed in the construction land intensive areas of the central urban area.(3)Based on the FLUS model to simulate the land use pattern in 2017,the overall accuracy is 80.28%,kappa coefficient is 0.7634,and the simulation effect is good.Comparing the spatial distribution of land use under the two scenarios in 2025,under the natural development scenario,the construction land shows an epitaxial expansion,the overall scale has increased by 225.99km~2,and the phenomenon of encroaching on ecological land is still prominent.While under the"three-line"constraint scenario,the transfer of ecological land is limited,and the expansion of construction land is restricted,the reduction of land area such as forest land and water area is eased,the cultivated land is increased slightly.(4)Compared with 2017,the ecological risk index of the two scenarios will increase in2025,among which the ecological risk level will increase significantly in the natural development scenario.In addition,the spatial distribution of each ecological risk level in the two scenarios is generally stable.Among them,the lower,low and high ecological risk areas of land use under the"three line"constraint scenario are larger and more concentrated.It shows that while strengthening the cultivated land and ecological protection in the study area,it also ensures the development of urban construction land,and enhances the stability of land use structure.The spatial distribution of land use is more conducive to mitigate the aggravation of ecological risk in the study area.Finally,based on the characteristics of land use change and the prediction results of ecological risks,and according to the comprehensive division of land use in Guangzhou,this paper puts forward corresponding countermeasures and suggestions for the optimization of land use and the regulation of ecological risks in the central,northern,southern and northeast regions.In order to optimize the spatial pattern of land use,enhance the ability of landscape ecological risk prevention,and promote the coordinated development of urban ecosystem and social economy.