Land Use Patterns Evolution And Scenario Simulation In Guanzhong Plain Urban Agglomeration

Land use/cover change is an important part of global change and sustainable development,and it is also the most direct signal to characterize the impact of human activities on the natural ecosystem on land surface.With the development of urbanization in China,extensive resource utilization methods and the disorderly spread of urban space have intensified the contradiction between the supply and demand of land resources,and the structural contradictions in urban,agricultural,and ecological spaces have become prominent.As the main form of my country's new urbanization,urban agglomerations play an important role as a strategic support point and core growth pole in the layout of productive forces.Therefore,taking the urban agglomeration as the research object,exploring the characteristics of land use change and simulating the future land use pattern are of great significance for realizing the rational use of land resources,coordinating regional social and economic development,and promoting the urbanization process of China with the urban agglomeration as the main body.This paper takes Guanzhong Plain urban agglomeration as the research area,and uses land dynamics,transfer matrix,spatial center of gravity transfer,land use degree and other methods to qualitatively and quantitatively analyze the evolution characteristics of land use pattern of Guanzhong Plain urban agglomeration from 1970 to 2015 from a time and space perspective.,Describes the characteristics of the land use mode and transfer direction,the speed of land use change,the shift of the center of gravity of the land,and the degree of land use change in the Guanzhong Plain urban agglomeration.On this basis,the Markov model and FLUS model are comprehensively used to simulate and predict the land use pattern in the three scenarios of the Guanzhong Plain urban agglomeration historical development scenarios in 2020 and 2030,cultivated land protection scenarios,and ecological priority scenarios.The main findings are as follows:(1)The land use types of Guanzhong Plain urban agglomeration are mainly cultivated land,grassland and forest land.Cultivated land shows a trend of gradual decrease,mainly distributed in the main grain production areas of Guanzhong area,which shows that the degree of fragmentation increases,and it is gradually cut by the expansion of construction land,from large-scale continuous patches to broken small patches;construction land The expansion is rapid,with Xi'an,the center of the urban agglomeration,Xianyang,Weinan,and Yuncheng,the sub-centers,accounting for the largest proportion of construction land,the fastest development,and the city's growth is notable and uneven.The land use rate was the largest between 1995 and 2000,and the land use rate of each county in the region increased to varying degrees.Since 2000,the difference in land use dynamics among counties has decreased,and the development speed has been more balanced.(2)The land use of the Guanzhong Plain urban agglomeration is developing in the direction of complexity and diversification,the process of type conversion is complicated,and the performance is different in different periods.The large transfer between cultivated land,forest land and grassland is a land use change The main features.The change of cultivated land is mainly manifested in the transfer of spatial location,and most of the construction land is reflected in a net change,that is,an increase in quantity.The largest source of growth in construction land area is cultivated land.(3)Affected by the rapid expansion of land use in Xi'an,the central city of the urban agglomeration,and the surrounding node cities,the center of gravity of construction land moved to the southwest as a whole;the unused land moved to the north-west of the whole;due to the relatively concentrated distribution of cultivated land,forest land and grassland Strong,the center of gravity shift distance is not large during the study period;due to severe soil erosion from 1980 to 2005,the shift distance was large,and the center of gravity of the water area moved to the southwest.(4)The land use degree of the Guanzhong Plain urban agglomeration has gradually increased,and the land use degree has shown a strong growth momentum from 1995 to 2000 and from 2010 to 2015.The areas with higher land use in urban agglomerations are mainly concentrated in Xi'an,Xianyang,Linfen,Yuncheng,and Weinan,that is,cities in the Guanzhong Plain and surrounding cities in Xi'an have a high degree of land development and utilization.The land use degree index of the same county has not changed much during the study period.The urban development intensity in the western region of the urban agglomeration is generally low,and there is much room for improvement in land use structure and benefits.(5)FLUS model was used to simulate the land use pattern of Guanzhong Plain urban agglomeration in 2015.Compared with the actual situation,the overall accuracy reached 91.4% and the Kappa index 0.87,indicating a high simulation accuracy.Farmland protection scenario and ecological protection scenarios have certain effects on the set land control goals,but they cannot achieve the optimal layout of the land use structure.According to the theory and model of land use optimization and the requirements of coordinated development of urban agglomerations,sustainable optimization scenarios are set to predict the optimization results of the land use structure of the urban agglomeration of the Guanzhong Plain,which has the potential to achieve sustainable land use patterns in the Guanzhong Plain in 2020 and 2030 Certain reference significance.