Evolution Of Urban Land Use Pattern In Tongzhou District,Beijing Based On SD-MCCA Model

As an important part of urban land,studying the rationality and scientificity of its evolution is of great significance to the optimization and development of land space in the future.At present,there is a lack of quantitative new urbanization policies in land use research.The research attempts to take Beijing’s urban sub-center and the third batch of new urbanization demonstration areas-Tongzhou District,Beijing as an example,using land use transfer matrix,land use dynamic degree,To explore the characteristics and causes of changes in urban land use in Tongzhou District,using methods such as geographic detectors,the SD model is used to quantify the quantitative demands of three scenarios,namely“conventional urbanization scenario”,“new urbanization scenario”and“reverse urbanization scenario”,and calculate the The MCCA model was introduced to predict the evolution of the spatial pattern of urban land use under different scenarios,so as to deeply analyze the evolution of the urban land use pattern in Tongzhou District from 1972 to 2030,in order to provide guidance for the next round of new urbanization demonstration areas.The results show that:(1)From the perspective of the time series changes of urban land use,in different periods,the characteristics of urban land use changes in Tongzhou District are not the same,and the dominant factors affecting its evolution and development are also different.From 1972 to 2015,the urbanization process of Tongzhou District accelerated,and the expansion rate of urban land continued to increase.The main sources of urban land were cultivated land and rural residential land,of which cultivated land was transferred to 79.03 km~2,accounting for 67.13%of the total source.In2005,cultivated land The transfer-in volume reached a peak value of 35.85km~2,and the total transfer-in volume of rural residential areas was 42.87km~2,accounting for 36.41%of the total source.In 2010,the transfer-in volume of rural residential land reached a peak value of 30.44 km~2.(2)The expansion directions of urban land from different perspectives are different.(1)From the perspective of the expansion direction of urban land from a global perspective,from 1972 to 2000,urban land mainly expanded to the northwest,and the expansion was most obvious during1980 to 1990.From 2000 to 2015,the expansion direction of urban land mainly expanded to the west and north.From the perspective of the central city,the expansion direction of urban land is mainly divided into three stages:"discrete","southward development"and"leap-forward".From the perspective of expansion types in different periods,"extension type"is the main type of expansion in Tongzhou District,but its dominant mode varies with urban development.(2)From 1972 to 2015,the expansion of urban land in Tongzhou District is mainly along the existing urban land to the surrounding area.Expansion is the main business,but since 2005,there has been a leap-forward development,and the proportion of this type of expansion has continued to increase.(3)From the perspective of the expansion mechanism of urban land use,changes in the scale of urban land use are related to a number of social and economic indicators.(1)The indicators that mainly affect the scale of urban land use in Tongzhou District are GDP,urban residents’disposable consumption amount,and primary gross domestic product,etc.indicator related.Under the detection of geographical conditions,the spatial expansion position of urban land is mainly related to a number of indicators such as road network density,population density,and distance from public service facilities.The road network density most affects the direction of urban land expansion in Tongzhou District;(2)The policy factors of land use change are basically consistent with the development of the national economy.(4)Based on the SD-MCCA scenario simulation under different scenarios of policy shocks,the spatial changes of urban land in Tongzhou District show significant differences under different scenarios,and the reasons for this difference are different.Under the conventional urbanization scenario,the urbanization of Tongzhou District develops rapidly,and the urban land area increases significantly.(1)The expansion method is the merger of rural settlements and the occupation of cultivated land,mostly in the south of the central urban area of Tongzhou;(2)under the new urbanization scenario,the urban land in Tongzhou District The scale is much higher than the conventional urbanization scenario.The main reason is that the investment in the secondary and tertiary industries has been increased under the new urbanization policy,which has accelerated the transfer of the rural registered population to the urban registered population,resulting in the accelerated transfer of rural residential land around towns.thereby accelerating the expansion of urban land use.On the other hand,affected by the spread of urban land in the central urban area of Beijing,more and more people in the central urban area of Beijing will move to Tongzhou in the future,which will further accelerate the expansion of urban land use in Tongzhou;(3)It is a phenomenon in which urbanization is over-developed or develops to a certain stage,and the urban population transfers from cities to suburban and rural areas.Under this scenario,the urbanization development speed of Tongzhou District slows down,the urban population outflows,the growth rate of urban land decreases,and the rural residential areas slow down.The growth rate has exploded,especially in areas close to urban land.This is because such areas not only enjoy the natural scenery of the countryside,but also enjoy the convenience of public facilities in cities and towns,so that the cultivated land in such areas is seriously occupied by rural settlements,it can be seen that due to the impact of reverse urbanization,the land for rural settlements around the city will expand significantly,so it is necessary to formulate reasonable land policies for these areas;(4)The comparison between the new urbanization scenario and the conventional and reverse urbanization scenarios shows that under the interference of the new urbanization policy,urban land is more intensive,the degree of aggregation of rural settlements is strengthened,and there is a trend of forming new market towns in some areas.This is due to the fact that rural residents When the points are gathered to a certain extent,a new market town will be formed.