The Impact Of Xiong'an New Area On The Evolution Of The Spatiotemporal Pattern Of Landuse In Beijing

Currently,metropolises generally encounter the problems caused by population expansion during rapid urbanization,therefore,population transfer is regarded as an important goal of urban development and planning.In April 2017,the state proposed a millennium plan for the establishment of the Xiong'an New Area,which has an important impact on Beijing's Population and Land Use.A reasonable estimation of the contribution of the Xiong'an New Area to Beijing's population,and revealing its impacts on the urban land use will be of great significance to the urban development of Beijing.This study is based on the idea of “promoting population transfer by dispersing industries”and regards the establishment of Xiong'an New Area as a policy shock promoting industry transfer.In order to reveal the impact of Xiong'an New Area on the evolution of the spatiotemporal pattern of land use in Beijing,this study constructed a cross-region system dynamics model and a land-use simulation model that combines with a multi-agent system and cellular automata.The main works and finding are as follows:(1)By comparing the spatial distribution pattern and evolution of Beijing's land use from 1990 to 2000,2000 to 2015,and 2015 to 2018,we found that the urban land expansion of Beijing has shown a trend that transit from a “mono-centric expansion”to “mono-centric+ multipolar expansion”.Based on the point of interest(POI)data,the distance attenuation of the POI density is used to identify the agglomeration centers that include major industries such as residence,business service,and industry.The development of the commercial service industry in the outer suburbs is still small.(2)Based on Beijing's development goals in the economy,employment,and energy,a multi-objective optimization model of Beijing's industrial structure was constructed,and three industrial transfer scenarios(including a neutral growth scenario,an employment priority scenario,and an energy control scenario)were set according to different weights of development goals.Genetic algorithms were employed to capture the optimized industry structure under different transfer scenarios.From the perspective of the average extent of changes in industry structure of different industrial transfer scenarios,industries including wholesale and retail,accommodation and catering,real estate,agriculture,electricity,heat production and supply,leasing and business service,construction,and manufacturing need to get transferred to Xiong'an in priority,and wholesale and retail,accommodation and catering industries have the largest changes extent,falling to 45.63% and 38.56% of its proportion of output value in 2012,respectively.Among different industrial dispersing scenarios,the industry structure of the employment priority scenario is basically the same as the neutral growth scenario,but the energy control scenario will increase the extent of transfer in the manufacturing and construction industries but reduce the decentralizing extent of the leasing and business service industries.(3)Based on the system dynamics(SD)method,we introduced the labor influence coefficient and constructed a cross-region SD model to predict population and land demand affected by industry transfer.The cross-region SD includes a sending system(Beijing—Transferring Subsystem)and a receiving system(Xiong'an New Area—Undertaking Subsystem).The results show that the rising of the Xiong'an New Area can restrain the continued growth of Beijing's population to some extent.Under different industrial transfer scenarios,the population of the energy control scenario will basically maintain the current size of 2018,while the population of the neutral growth scenario and the employment priority scenario will slightly decrease compared to 2018.From the perspective of the ways in which the population is affected,the depopulation of Beijing mainly depends on industrial transfer.The outmigration of labor forces during 2018 and 2035 can reach about3.09?3.68 million people.In the short term,the population that directly migrated from Beijing to Xiong'an New Area is relatively small,accounting for about 8.3% to 9.2% of the labor force outmigration.However,the overall population size of Beijing that migrates to Xiong'an every year presents a trend of rapid increase.(4)Under the background of industrial transfer,the agents(enterprise agent,residents agents,government agent)and their behaviors during the land-use decision-making process were listed,and a land-use simulation model integrated with a multi-agent system(MAS)and cellular automata(CA)was constructed.The model is developed based on Python and combined with libraries including Num Py,Sci Py,etc..The model was used to simulate the land-use changes in Beijing from 2015 to 2018 under conventional scenarios,and the pixel-by-pixel comparison method was used to verify the accuracy.The simulation accuracy was 78.62%.(5)The simulation results of Beijing's land use in 2035 based on this model show that Beijing's industrial land,wholesale and retail land,accommodation and catering land,and public service land will decrease.Among them,wholesale and retail and accommodation and catering land will have the largest decline;However,land used for commercial and financial,and other commercial services will be further expanded.The increase of commercial and financial land nearly doubled compared with the conventional scenario.In terms of land use transition,the transition-out scale of industrial land in the core area of the capital,Pinggu,Yanqing,and Miyun has increased;wholesale and retail land will be increased in Dongcheng,Xicheng,Fengtai,and Shijingshan.The transition-out of accommodation and catering land in the core area of the capital is relatively high.In terms of the scale of transition-in,residential land in suburban cities has increased significantly;wholesale and retail land in the capital's core area has increased slightly compared to the conventional scenario;the transition-in of commercial and financial land and other commercial lands in the capital's core functional area would decrease but the transfer scale of outlying suburban counties would increase.