Study On Early Warning For Urban Land Intensive Utilization In Wuhan City With System Dynamics

Urban land intensive utilization is the basic measure and key link to solve contradiction between land and population and between resources and development. Early warning for it is to put its evolutive system under feed forward control.In the study, urban land intensive utilization was defined as a comprehensive system. And Wuhan city was the object of the case study. Based on the conceptual model of urban land intensive utilization, in the study, a system dynamics model was constructed for system simulation and an index system for warning system. Theory and methods of early warning were used to given warning limit and warning degree to reflect alert situation of urban land intensive utilization from2012to2020, and to take measures before alert situation extends or breaks out. The study is a practical innovator for system emulation and early warning. And there are three conclusions.Firstly, urban land intensive utilization system of Wuhan city is composed of land utilization subsystem, population subsystem, economic subsystem and environmental subsystem. The four subsystems are linked by urban production activities. Based on the system structure analysis, the system dynamics model of urban land intensive utilization system was constructed by analyzing the causal relationships within and between subsystems, designing variables and establishing equations between variables. The simulation results showed a very good simulation effect via urban land intensive utilization system dynamics model. The early-warning index system reflected future alert situation in factors, subsystems and the system via scientific warning limit.Secondly, there will be light-level to medium-level alert situation in urban land intensive utilization system of Wuhan city during2012to2020. It is due to three reasons. One is that urban land will expand faster than urban populations because of the insufficient utilization efficiency. It will cause light-level alert situation in coordination between land utilization and population subsystems. Second is that because of the insufficient intensity of using urban land, expansion of urban land will be cultivated land and ecological land occupation and cause serious alert situation. Third is that because urban land utilization doesn’t meet the demand of urban population, there will be the most-serious-level alert situation on social effect indexes of urban land intensive utilization.Lastly, land resources protection, urban land use planning and appropriate combination of inputs were given to control the possible alert situations in urban land intensive utilization system of Wuhan city. And relevant controllable factors were designed as policy factors to change system trends, which includes percentage of cultivated land occupied for construction, building coverage ratio, plot ratio, proportion of construction investment in urban development land area per capita, wages of labor and the contribution rate of technological.