A Study On The Interaction Mechanism Between Urban Residential Land Expansion And Land Price Fluctuation In Wuhan City

During the process of pursuing the dream of urbanization,China attracted world's attention with extensional and intentional development of urban land use,but also faced with a variety of “urban disease”: population explosion,traffic congestion,housing shortage and urban overspreading etc.Those problems continue to warn us that urban development should be compatible with the carrying capacity of resources and environment,and the law of urban development must be recognized,respected and complied with.While in a situation that the relatively independent of the government macroeconomic regulation of the land price measures and the expansion and control policy dominated by planning control policy failed to achieve the desired effect,how to accurately identify the collaborative process and refine the interaction mechanisms of residential land expansion and land price change,and to explore the scientific measures are of great significance for achieving optimal regulation of urban construction in the new period and balancing urban and rural development.Wuhan,as a large city in a developing country,has been developing rapidly in the past two decades under the promotion of the development strategy in the Central China,and its urban residential land expansion and land price change are significant.By integrating the techniques and methods of RS,GIS,spatial statistics and model evaluation,this paper aims to explore the spatiotemporal change of urban residential land expansion,clarify the spatial directivity characteristics of residential land price changes,summarize the urban residential land expansion process and land price evolution,refine the relationship between the two factors,analyze the pattern response,model the interaction mechanism based on impact factors' characteristics,reveal the interaction mechanisms and provide suggestions and measures for optimal regulation.The main contents and conclusions are as follows:(1)Based on the summary of related research both at home and abroad,and the urban expansion and land price theory,this paper defines the expansion of residential land as the process of land conversion from residential,non-residential and external natural matrices into residential land and residential land structure,which belongs to the category of single area expansion and is part of the expansion of the city.Under the premise of residential land expansion and the division of land price change,this paper extracts the structural framework and evolutionary mode of interaction between urban residential land expansion and land price change based on urban planning and land market.(2)This paper analyzes the temporal change of residential land by grade clock,economic density of land and other methods,and analyzes the spatial change of residential land with center of gravity migration and intensity of expansion so as to reveal the spatiotemporal dynamics of residential land expansion in different administrative regions and natural regions.The results showed that:(1)The residential land scale index grade clock clearly shows the change of residential land use in seven main urban districts of Wuhan from 2001 to 2014,of which Hongshan District ranks highest and Qingshan District ranks last.While the regions predominated by tertiary industry have much higher land economic density than that predominated by industry(2)The center of the residential land in the seven administrative areas shows a trend of outward movement and the overall expansion is quite strong between the second ring and third ring of Wuhan,which has a higher consistency with the development of the sub-center in the suburbs.(3)The expansion of residential land shows the characteristics of low-quality and extensive suburban expansion in quality and the pattern of multi-center cluster and infill expansion between shafts,the expansion of the traffic axis and the expansion of the lake-surrounding in structure.(4)The income increase,the development of technology,the reform of economic policy,land use system and housing system and the regional differentiation of population structure have direct or indirect influence on the expansion of residential land.(3)On the basis of testing the spatial structure and spatial autocorrelation of residential land prices data with spatial probing data analysis method,Kriging method is used in spatial interpolation of residential land.The process and law of temporal and spatial evolution of residential land price are revealed from the comparison among land prices interpolation,the interpretation of land price profile and land value-added performance.Results show that:(1)The spatiotemporal change of residential land price demonstrates a higher rising speed and a trend of layer pattern.The high-value sectors of the residential land prices shift from obvious single apex to multi apexes,with the directional characteristics of lake landscapes emerging gradually.(2)The cross-section analysis demonstrates that the residential land prices from the basic point to the urban fringe in Hankou district,Wuchang district and Hangyang district of Wuhan city shows a gradual decrease from the central region to the periphery,with gradients and mutations coexisting.(3)According to the two-stage division of residential land price change,the first stage(2001-2007)mainly shows a centripetal trend of residential land prices,with the rapid marketization of land,the location advantages of urban sub-center and land premium increasing accordingly.The second stage(2008-2014)is mainly embodied in the stage of centrifugal development of land prices.Under the guidance of urban planning,residential land prices regrouped to form a circle structure centered on the city sub-center.(4)Studying the interaction mechanism between the residential land expansion and land price fluctuation,it is found that residential land expansion and land price react through the urban planning and land market two carriers,with positive effect and negative effect coexisting.The evolution of spatial pattern presents coupling model,with timing lag existing during the action process,which shows that the interactive relationship between the positive and negative effect is demonstrated by certain impact factors quantitatively in a micro level.Specifically:(1)From the perspective of function channel,the expansion of residential land impacts land price through urban planning,in return,the influence of land price change on residential land expansion is demonstrated in the land market.The spatial differences of residential land prices result from the urban positioning and administrative levels,economic growth and industrial replacement,functional zoning and industrial policy orientation,land structure and supply mode,location and other factors.Conversely,the expansion of residential land is also influenced by the population growth and mobility,improvement and investment demand,socio-economic development and land finance policies,industrial and commercial land and conversion of agricultural land,residents' choice of preference and residents' purchasing power.From the perspective of the effect,on the one hand,the lack of land supply and “urban overspreading” development model will effect land price growth positively,while the regional structure manifestation will promote or inhibit the growth of land price.On the other hand,the chasing of land finance by local governments and the increase of residents' purchase of houses will play a positive role in the expansion of residential land.In addition,the increase of land market,the restriction of land resources and the implementation of real estate restriction policy and the cost increase of residential land expansion will restrain the expansion of residential land.(2)From the perspective of spatial pattern,the change of the dominant expansion direction of the residential land in Wuhan has led to the trap axial gradient of ring structure expansion of the land price and promoted the overall elevation of the land price in the urban residential group.At the same time,the evolution of the spatial pattern of residential land led to the displacement of the central point of the land price,the networked land price structure and the local price mutation.On the contrary,the spatial distribution of residential land price affected the living space structure and a new round of residential land planning.(3)Analyzed the residential land change rate unit area(1km*1km)and land price gradient Pearson correlation,it is not hard to find that: From the perspective of geographic area,the inner area of second ring showed more obvious correlation than the area from the second to the third ring.While in the area from the second to the third ring with larger area of residential land expansion,weak correlation emerged;from the perspective of administrative area,Wuchang and Hankou showed obvious correlation,while Hanyang district showed no obvious correlation.In addition,the effect the residential land change on land prices change has a time lag,while the residential land prices change shows no obvious time lag in the expansion of residential land.The analysis of typical sample area reveals the interactions of the two respects.(4)According to the results of GWR model,residential land expansion characteristics showed obvious spatial non-stationarity effects on the land prices: during the process of the residential land expansion,the spatial distribution of land prices is reshaped with the formation the city center(sub-center),showing a centrifugal development model in a whole;the influence of the main road on land price premium is more obvious in the suburbs than that in the city center.Lake landscape premium enhanced gradually as well,which resulted in a higher marginal value in a prosperous area,while the big lake(the East Lake etc.)landscapes have anisotropic impact on the residential land prices.(5)Having analyzed the impact of the land price changes on expansion of residential land use with geographical detector,it is found that residential land use potential and realization level of residential land price have stronger ability to explain the residential land expansion,and the comprehensive ability after coupled reinforced each other.(5)In accordance with the control mode of “direct target–regulatory target–ultimate goal”,the optimal regulation and control model is constructed from three aspects: residential land expansion subsystem,residential land price subsystem and their synergistic development system:(1)The regulation of residential land expansion should be controlled by general rules,regulations,detailed classification to make the expansion of residential land improve in a way of moderate scale,reasonable structure and high efficiency.As to the control of the land market,we should establish a just,fair and open land market trading platform and build an integrated land market in urban and rural areas by demonstrating the market mechanism and the principle of appropriate government intervention.(2)During the operation of the system,the expansion of urban residential land is monitored through the demand ratio of residential land,the vacancy rate of residential land and the proportion of the type of residential land.The land prices changes are monitored by the land price rises ratio,the GDP growth rate and income increase rate,always keeping both in a relatively reasonable interval,so as to realize the optimal allocation of urban land use.The main innovations of this study include:(1)This paper refined the urban expansion research from the perspective of single land use,characterized and depicted the spatiotemporal characteristics and rules of the residential land expansion in Wuhan.In order to reveal the development trend and law of expansion of single type land in megacity cities of developing countries,the GIS and RS technology etc.are applied in this study to extract the residential land expansion data of different years in Wuhan city.The spatiotemporal changes in different administrative and natural area of residential land expansion are depicted and characteristics by the methods of rank clock and city center gravity shift,and the index of land economic density and expansion intensity etc.The quality and structure of expansion have been refined and the driving forces have been analyzed from the perspective of economy,population,policies and technics etc.,which provided references for the expansion of different land use types.(2)This paper did research on the interaction mechanism of spatiotemporal process between the residential land expansion and the land price changes.Based on the dynamic residential land expansion and the temporal and spatial rules of land price changes,the interaction mechanism analysis framework of the residential land price fluctuation has been modeled on the basis of the urban expansion and the residential land expansion in land market.The function channel and the interaction mechanisms are quantitatively analyzed.From the perspective of “relationship”,GWR model was used to explore the quantitative impact of impact factors on the residential land prices change in a microcosmic point.What's more,this study further revealed the spatial directional changes of city sub-center,main roads,lake landscapes etc.,explored the interaction mechanism of impact factors(realization level of residential land prices,residential land use potential etc.)on the residential land expansion with geographical detector and highlighted the dynamic rules and the instruction value of model simulation results on the urban residential land expansion and land price regulation practice.