Simulation And Prediction Of Land Use Change Based On Landscape Pattern And MCE-CA-Markov

As an important resource and material basis for human survival and development,land is the link between human beings and the natural environment.Land use change involves a series of natural social and economic issues such as ecological balance,food security,and urban and rural development.It is the most direct reflection of human-land relations.Therefore,it is of great significance to explore the law of land use change,analyze its dynamic evolution and influence mechanism,and then simulate and predict future land use change,which will alleviate the contradiction between people and land,scientific planning land use,and realize the sustainable use of land resources.In 2017,the 13 th Party Congress of Chengdu proposed the cross policy of sustainable urban development,namely “Dongjin,Xikong,Nantuo,Beigai,Zhongyou”,while Dujiangyan City is located in the northwest of Chengdu Plain.The famous tourist city of nature and culture naturally assumes the carrier function of the most important ecological conservation and civilization inheritance in the "West Control".However,it is currently in the background of China's rapid economic development.For this reason,Dujiangyan City needs to coordinate the relationship between ecological environmental protection and economic construction,and rationally plan the land use structure to achieve comprehensive and sustainable regional development.In view of this,from the perspective of landscape ecology,the paper takes Dujiangyan City as the research area,and selects the land use status map and DEM image of the three phases of 2005,2010 and 2015 as the basic data source,using spatial analysis,dynamic degree and landscape.The pattern index and other methods comprehensively analyze the regional landscape pattern change characteristics and influencing factors,and predict the land use landscape change in the study area in 2020 and 2025 based on the MCE-CA-Markov model,and then propose targeted policies.The main conclusions of the paper are as follows:(1)Through the analysis of land use dynamics,land use structure change and land transfer in Dujiangyan City,the law of land use change was explored.In 2005-2015,the conversion area of cultivated land,construction land and garden land was the most active,and the cultivated land was in a state of decline in the past ten years of the study period,mainly flowing to the construction land,With the integration or demolition of rural settlements,some construction land was converted into cultivated land,but the transfer of garden land also increased the land for urban construction.Obviously,the cultivated land was “not enough to make ends meet”.The amount of grassland,waters and other land use was slightly smaller than the amount of transfer,and the conversion between the three and other land use types was not obvious.(2)Using the landscape index to deeply analyze the characteristics of landscape pattern changes in the study area.In the whole study period,the number of plaques increased,the plaque area and aggregation degree decreased,and the fragmentation increased.On the contrary,the construction land showed a contiguous development trend;forest land and cultivated land accounted for the largest proportion of landscape area,but with The improvement of the economic level of Dujiangyan City and the acceleration of urbanization process,the dominance of the two is decreasing year by year,and the dominant plaques of construction land are becoming more and more obvious.At the same time,the fractal dimension and shape of the landscape level of the third-stage land type are both Development towards simplification and regularization(3)Paper analyzed the influencing factors of land use pattern,such as slope,road,river,administrative center,etc.,which have significant impact on land use pattern.Among them,the cultivated land is mostly distributed in the area with low slope,close to the river and far from the city center;and the construction land is obviously increased in the area with lower slope and close to the river,road and administrative center,and the land type is affected by the spatial distribution.The adsorption of rivers,roads and administrative centers is strong;the forests are concentrated in mountains and hills far from the city center and moderately sloped,which are less affected by human activities;the distribution of grasslands,gardens and other land is relatively scattered,and the scale of land occupation is small.(4)The CA-Markov model under multi-criteria evaluation can better simulate LUCC in Dujiangyan City.In this study,five types of impact factors were selected from the natural and social aspects.The suitability atlas was produced by the multi-criteria evaluation(MCE)method,and the land use situation in 2015 was simulated by the CA-Markov model,and compared with the actual situation in the same year.Both the quantity and the space have passed the test,and the simulation effect is ideal.(5)Forecasting the land use situation in Dujiangyan City in the future.This study re-enacts the MCE-CA-Markov model,using 2015 as the base period data to predict land use in Dujiangyan City in 2020 and 2025.It is concluded that the area of cultivated land,forest land and other land uses continues to decrease,including planning and returning farmland to forests.The impact of policies on the reduction of forest land is relatively slow.On the contrary,the construction land is growing continuously,and the waters and grasslands are not changing much.The difference in the proportion of land use structure in the entire study area has gradually narrowed and stabilized.