The Research Of Ecological Risk Of Land Use Change In North China Plain

In recent years,the risk of natural disasters caused by climate change has significantly increased globally,posing a significant threat to humans and ecosystems.In addition to natural disasters,climate change and land use changes driven by human activities can also increase ecological risks by reducing the supply of ecosystems to human well-being.However,compared to the mature risk assessment framework in the field of natural disasters,the ecological risk of land use change is still a completely new concept,with no mature definition of either the connotation or the assessment method.Therefore,with the help of the classic framework in the field of disaster risk assessment,this study selects the North China Plain as the study area,and takes "analysis and simulation of land use change-assessment of ecosystem services-spatial identification and assessment of ecological risk" as the logical framework to analyze the spatial distribution of ecological risk levels under three development scenarios in the North China Plain.First,this study uses the Change Analyst module of the Terr Set software to analyze the characteristics of land use change in the North China Plain from 2000 to 2020 from the three perspectives of the quantity,transfer and spatial change of land use,so as to grasp the evolution law of land use in the study area in the spatio-temporal change(Chapter 3).Then,CA Markov model was used to simulate the land use change of "natural development scenario","urban expansion scenario" and "ecological protection scenario" in the North China Plain in 2030,and the possible situation of future land use change in the study area was obtained(Chapter 4).Secondly,the four ecosystem service functions of water production,habitat quality,carbon storage,and soil conservation in the study area under the three development scenarios of 2020 and 2030 were estimated,and the spatial distribution and quantitative changes of the four services were analyzed and explored in depth(Chapter 5).Finally,the Sharpe ratio of economic investment risk return is introduced as the ecological risk assessment model of this study,integrating the land use simulation results and ecosystem services into the ecological risk assessment framework,and identifying and analyzing the spatial and temporal differences of ecological risks of land use change under the three development scenarios in the North China Plain in 2030 from two aspects of spatial distribution and quantitative change(Chapter 6).The main conclusions are as follows:(1)The land use type of the North China Plain is mainly cultivated land,followed by forest land and construction land,and other land types are less distributed.Between2000 and 2020,the area of cultivated land,grassland,and unused land in the plain decreased as a whole,while the area of water and construction land increased as a whole,while the change in forest land was not significant.(2)Under the natural development scenario of the North China Plain in 2030,the land use change will be the decrease of cultivated land,forest land and grassland,and the increase of construction land,water area and unused land;Under the scenario of urban expansion,the proportion of construction land in the hinterland of the plain has the largest increase;Under the ecological protection scenario,the proportion of forest land and grassland in the area at the foot of the Taihang Mountains in the Yanshan Mountains at the edge of the plain has the largest increase.(3)The spatial differentiation of total ecosystem services in the North China Plain is obvious,and the overall trend is from the middle to the surrounding space.In the three scenarios,the total amount of ecosystem services ranked from large to small: ecological protection scenario>natural development scenario>urban expansion scenario.(4)Considering the possible situation of future land use change and ecosystem service function,the ecological risk of land use change in the North China Plain presents a spatial trend of greater risk in the north,less risk in the south,less marginal risk,and greater risk in the hinterland,with medium risk as the main risk.According to the severity of ecological risks,the three development scenarios are urban expansion scenario>natural development scenario>ecological protection scenario.