Urban Planning Spatial Decision-making Model Based On Multi-Agent System And Its Application

Urban spatial system is a complex system. Its spatial evolution is characterized by j a number of microscopic behavior agents (enterprises, residents, farmers and various organizations) with activity and adaptability and nonlinear interaction between agents and the environment,which results in non-continuous urban spatial decision-making behaviors. Due to static characteristics, traditional model of urban planning spatial decision-making can't reflect the accumulation process of time dimension and aggregation process of spatial dimension in urban planning spatial decision-making interaction by large number of microscopic agents. Therefore, the traditional way is difficult to embody the essence of public participation in urban planning decision-making, and actuality and acceptability of urban planning are subject to a certain restriction. Based on actual needs of urban planning and management, this thesis tries to combine multi-agent system theories and technologies related to geographical information science, computer science and intelligence science, and build urban planning spatial decision-making model which can clearly expresses spatio-temporal explicit characteristics of urban planning decision-making by agents participating. On basis of the model, it carries out simulation of urban planning spatial decision-making for Changsha city, and assists understanding relevant non-structured problems arising from urban planning management, so as to improve the scientificity and reasonability of urban planning spatial decision-making and provide reference to sustainable urban development in China. Main conclusion of the research includes:(1) This study has designed urban planning spatial decision-making behaviors and rule system based on interaction among multi-agents and built series of urban planning spatial decision-making models focusing on multi-agent system. Compared with urban planning spatial decision-making model based on cellular automaton and traditional urban planning spatial decision model based on GIS, multi-agent urban planning spatial decision-making model improves greatly the ability of interpretation of the reasons for urban spatial system evolution and simulation of evolution process of urban spatial system, respectively, which enhances its capacity of representation of urban spatial evolution and helps people to understand the mechanism of action and interaction process under the presentation of urban spatial evolution.(2) Based on multi-agent system theory, this study has established spatio-temporal allocation rule for urban land resources and built dynamic urban land expansion model which is able to describe interaction relationship among agents affecting urban land expansion. The model is suitable for interpretation of reasons for urban land expansion and understanding of impact of agents'behaviors on urban land expansion process, with higher simulation accuracy, so it can provide auxiliary decision-making support on formulation of land use policies for government and urban planners.(3) Restricted by multiple objectives and based on actual problems in spatial optimal allocation of urban land use, this study has built spatial optimal allocation model of urban land use integrating multi-agent system and heuristic algorithm. This model not only can obtain reasonable and feasible optimal allocation result of urban land use, but also has good operation efficiency and objective optimization capacity.(4) With support of multi-agent system, this study has built multi-agent interactive spatial site selection model on the basis of dynamic information feedback mechanism, enabling agents participating in urban planning to communicate their own knowledge and information frequently and reach consensus on decision making ultimately, so as to get the solutions of site selection problems. The dynamic information feedback mechanism designed in the model can effectively express the communication and learning process of agents, and enables multi-agent interactive spatial site selection model to be better than spatial overlay analysis commonly used in traditional site selection model, so as to make the model provide effective solutions to site selection for construction project. (5) Taking Changsha, the typical city in central China and the core area of Changsha, Zhuzhou, Xiangttan city group, which is the national comprehensive reforms test areas of building resource-saving and environment-friendly society, as an example, urban land expansion, multi-objective spatial optimal allocation of urban land use, construction project site selection of changsha city was simulated and analyzed based on developed urban planning spatial decision-making model, so as to provide theoretical basis and decision-making support for urban planning management of this region.Multi-agent urban planning spatial decision-making model is still in the phase of theoretical study, leaving a huge space for follow-up research, and its theoretical depth, simulation accuracy and applicability still need further exploration.