Simulation of urban affordable housing land-use evolution based on CA-MAS model

In order to simulate the evolution of affordable housing land use a dynamic model that combines cellular automata CA and a multi-agent system MAS is established.This paper aims to utilize the approach of decision factors on site selection of affordable housing through a literature review to construct a hierarchy model of those factors identifying the weight of each factor by an analytic hierarchy process AHP .Based on those weight factors the CA-MAS model is designed. Nanjing city is taken as an example to verify the feasibility of the model.The results show that the CA-MAS model is pragmatic and effective in simulating evolution of affordable housing land use which also promotes the fundamental understanding and perception of the development of affordable housing and urbanization.

北京市人口时空变化与情景预测研究

利用第五次和第六次人口普查数据,分析北京全域乡镇街道尺度人口空间变化格局特征,并借助CA-MAS模型对未来城市人口格局进行情景模拟,以期增进对北京人口时空动态的认识,为北京城市管理决策和宏观调控提供科学参考。研究表明:1 2000-2010年,北京常住人口年均增长率高达3.5%,年均增加近60万人,是同期我国人口增长最快的特大城市之一;2北京全域人口变化在空间上具有明显的圈层式特征,集中表现为中心区人口增长几乎停滞、近郊区人口快速增长、远郊城市发展新区人口高速增长、远郊生态涵养区往往仅区县政府驻地及重点乡镇人口明显增长;3基于CA-MAS的情景模拟分析表明,在自发布局情景下,就业机会进一步向城市中心集聚,人口居住不断郊区化,这将增大城市的通勤压力,加剧城市交通拥堵状况,而通过调整就业参数,强化工作地居住功能的引导政策,则能在一定程度上解决城市内部空间尺度产城失衡的问题,可促进小城镇群的形成,有利于降低城市通勤压力,发挥城市的辐射和扩散作用。本文认为,为实现北京人口空间布局优化,应着力促进就业与居住相协调,推动区域间公共资源均等化,规划多中心组团发展。