Study On The Supply And Demand Forecasting Of Urban And Rural Construction Land Replacement Based On System Dynamics

Recently in the process of promoting new urbanization in China,the need of urban development land is increasingly and the scale of urban construction land is constantly expanding,and there are a lot of extensive,idle,waste and other phenomena in the current use of urban and rural construction land use.In our country,however,the cultivated land protection policy is most stringent and the total construction land use is strictly controlled.Imbalance of land use between supply and demand becomes increasingly prominent due to irrational use of urban and rural construction land use.As a result,urban development has been restricted.Therefore,actively develop replacement of urban and rural construction land use is put forward to effectively protect cultivated land,release supply and demand contradiction of urban and rural construction land use and promote land intensive and economical use.This paper performs prediction research about supply and demand of urban and rural construction land use in Chongqing.By analyzing gross balance state,the sensitive factors that influence urban and rural construction land use replacement in Chongqing is figured out,which could offer certain reference to land intensive and economical use and order development land use of urban-rural construction in Chongqing.Based on the research data of land use change from 2004 to 2013,this paper analyzes the situation of the amount,structure and function deployment of urban and rural construction land use in Chongqing during the recent 10 years.It is also figured out the problem that exists in the interior structure and land layout of urban and rural construction land use.Based on the social-economic data in the Chongqing Statistical Yearbook for nearly 11 years,it analyzes the change of population,GDP,land,investment in fixed assets and provides a variable data basis for the following model.Based on system dynamics,the model mainly considers certain influence factors of supply and demand system,such as society,economy,industry and land use.As for urban construction land use,it is mainly considered the newly added land-use types of commercial and commercial housing of profit-oriented land.Based on systematic analysis of urban and rural land use replacement,according to the system dynamics modeling steps,the supply and demand system can be divided into three subsystems,which are population subsystem,economy subsystem and land use subsystem.Bydeciding the system boundary and introducing the relevant variables,the causality graph and system flow graph are drew and system feedback circuit is analyzed.On the basis of Vensim software and the data of Chongqing from 2004 to 2014,the quantitative relation among the variables in the system flow graph is further confirmed.The relevant parameter value is also estimated.The model is constantly modified and adjusted until it passes the verification.Based on the effective model,three different situations are set to simulate the need of urban and rural construction land use replacement in Chongqing from 2004 to 2030 by analyzing land intensive and economical use and economy development adjustment policy.From the simulation prediction result,to the year of2030,supply cumulant of the rural construction land use in Chongqing can generally meet the need of profit-oriented land use under the situation settings.What's more,by comparing the situation settings,the demand of profit-oriented land in Chongqing can generally be controlled by increasing urban housing average floor area ratio.