【作者】 刘勇；

【导师】 吴次芳；

【作者基本信息】 浙江大学 ， 土地资源管理， 2008， 博士

【摘要】 改革开放以来,城市以空前的速度增长,中国的城市化已成为影响经济社会发展的主题之一。对城市增长的时空特征、演变过程、驱动因素的探讨以及对未来城市增长的预测一直以来都是城市相关领域的研究热点。在快速城市化地区,如何有效引导和调控城市增长,控制城市外延扩张带来的负面影响,就成为现阶段亟待研究的现实问题。根据等级理论,尺度被认为是描述现实世界层次结构的核心概念。城市可看作是具有等级结构的复杂系统,在研究城市增长与景观格局时必须充分考虑尺度问题。一般认为,尺度包括时间尺度、空间尺度和决策尺度,其中,空间尺度又可分为粒度和幅度。在城市景观格局分析和景观动态变化模型中,尺度问题对分析结果影响显著。近期研究十分强调模型的多尺度分析能力,以解决尺度依赖性问题。已有城市景观的粒度和幅度分析方面的研究成果颇丰,而元胞自动机等城市增长模型的尺度研究相对较少,尤其缺乏规划和管理角度的尺度问题研究。因此,在以往研究的基础上,本文具体探讨城市增长空间驱动因素的尺度依赖性、城市景观格局的多尺度分析、城市增长模型的尺度敏感性;同时,充分利用遥感数据和经济社会数据,对杭州市的城市增长过程进行实证研究。本文的总体研究框架分为尺度、方法和结果三个部分。首先,从尺度概念界定出发,提出空间幅度的研究思路。接着,利用定量研究方法,研究城市增长的影响因素、变化过程和未来模拟。最后,总结论文的结果与发现。本文共分为7章,所作的主要研究工作如下:第1章为绪论,阐述研究背景和意义。第2章较为全面地概括城市增长与景观变化的尺度问题,指出城市景观分析和模拟中应进一步探讨尺度问题。第3章提出研究的总体设计,将等级理论和扩散-凝聚理论作为理论基础,并介绍数据收集过程和主要的研究方法。第4章为城市增长空间驱动因素的尺度依赖性分析,在变化概率、变化密度、变化强度的多尺度分析框架中,引入变化时序的研究。选取经济社会因素、生物物理因素和政策规划因素等作为解释变量,利用探索性空间数据分析和空间logistic回归模型,建立不同尺度上城市增长格局与空间驱动因素的定量关系。对杭州市的研究表明,次要道路、城市建成区和空间政策尺度依赖性较弱,而主要道路、可开发用地规模和人口变化尺度依赖性较强。到主要道路和工业中心的距离、可开发用地数量和人口增长区域是影响大规模城市开发的重要因素,而与次要道路和建成区的邻近度是影响开发概率和开发时序的主要因素。第5章为城市景观格局变化的多尺度分析,从城市区域和城市土地利用两个层次出发,采用景观梯度分析与景观填充分析发现城市开发概率、探测其变化密度。将景观格局分析应用于城市区域和城市土地利用两个层次时,前者应侧重选取破碎化程度指数,而后者应侧重选取城市斑块形态和连通度指数。本章沿杭州市扩散廊道设置5个景观梯度,结果表明各个梯度带的城市平均斑块面积沿中心往外逐渐降低,经过开发区的梯度带表现为多峰值变化,而城市景观形状指数在城市郊区未出现显著下降。对大规模城市斑块的分析发现,杭州市建成区的分维数为1.76,具有理想的填充能力;自发增长较少和边缘增长占主导,决定其填充增长规模较小。杭州市城市增长在1996年后逐渐由扩散走向集聚,但还未达到成熟阶段。第6章为SLEUTH模型的尺度敏感性分析及城市增长多方案预测与评估。探讨SLEUTH模型的尺度敏感性时发现,当空间幅度增大时,不可预见性因素增多,从而使自发增长较多,加之低密度开发导致模型校正结果出现偏差。因此,适当降低模型的蔓延系数、合理设置排除层有助于防止过度增长。利用SLEUTH模型对杭州市城市增长进行多方案预测,生成现有发展趋势、交通导向、农田适度保护和紧凑城市4种方案,并从增长数量、空间分布、规划表现力3个不同方面评估上述4种方案的优劣。结果表明,若维持现有趋势增长,可能会突破规划确定的用地规模,加剧耕地的破碎化程度;通过交通引导城市向热点地区集中,有助于防止城市过于分散;采取农业适宜性限制和实施紧凑城市方案有助于边缘增长。最后,对SLEUTH模型模拟能力的结果表明,应该加强对突发性政策因素的模拟。第7章根据以上分析得出结论并讨论其中所存在的不足,同时简要分析研究结果的政策含义。更多还原

【Abstract】 Since the reform and opening up, rapid urbanization has become a prominent phenomenon influencing social economic development in China. Research on spatial-temporal pattern, dynamics, driving forces and modelling of urban growth has long been a focus in urban studies. In practice, it is urgent to study how to guide urban growth to reduce the negative impact of excessive growth in rapid urbanization areas at present.According to hierarchy theory, scale is now increasingly recognized as a central concept in the description of the hierarchical organization of our world. In urban studies, scale can be essential to understanding urban complex systems. In general, scale can be threefold: temporal, spatial and decision making, where spatial scale can be further divided into grain and extent. The variations of scale have been shown to affect the analysis of urban landscape pattern and simulation of landscape change. Therefore, Multi-scale framework is integrated into the modelling to deal with scale-dependence in recent studies. The grain and extent effect of landscape pattern have been focused for a long time, but the sensitivity of urban growth model such as Cellular Automata to scale relatively lack by now. Especially, rare attention has been paid to the scale issue from the perspective of master plan or land use planning and management. Thus this dissertation specifically explored scale-dependence of spatial determinants of urban growth, and a multi-scale method of urban landscape pattern analysis as well as urban growth model’s sensitivity. This dissertation took Hangzhou metropolitan area as a case study based on remote sensing and social economic data.The flowchart of the dissertation included three parts, namely scale, methods and results. This dissertation started from the definition of scale concept and put forward the way to study spatial extent. Then spatial determinants, dynamics and simulation were explored using quantitative methods. At last, findings and results were concluded. Accordingly, seven chapters were divided in this dissertation as follows:Chapter one was the introduction of research background and objectives. Chapter two reviewed the research of scale issue in urban growth and landscape change, and then pointed out the necessity of scale study in landscape analysis and simulation. Chapter three introduced the overall schedule of the research, including data collection and processing and hierarchy theory and diffusion-coalescence hypothesis employed in the study.Chapter four analyzed the spatial determinants of urban growth from a multi-scale perspective. According to relative studies, research questions of urban growth pattern can be divided into three subquestions: change probability, change density and change intensity. The dissertation put forward another subquestion of change sequence in the sense of temporal scale. Then exploratory spatial data analysis and logistic regression model were employed to uncover the relationship between spatial determinants and urban growth pattern in multiple scales. In the above model, social economic factors, biophysical factors and planning policies were selected as exploratory variables while change probability, density and sequence were dependent ones. The results showed that minor roads, neighbouring developed areas and spatial policies were influential across all scales, but major roads, neighbouring available areas and population change varied with scale in Hangzhou. Proximity to major roads and industrial center, neighbouring developable areas and population density increase were the major concerns for large-scale urban development in Hangzhou. Instead, proximity to minor roads and neighbouring developed areas were becoming the major concern at the scale of change probability and sequence.Chapter five analyzed the landscape pattern change in multiple scales. In urban area level and land use region level, analysis of landscape gradient and infill process could be used to infer change probability and change density respectively. In landscape pattern analysis, landscape fragmentation metrics should be used in urban area level while landscape patch shape and connectivity metrics in urban land use level instead. Five urban-rural gradients along the corridors of urban expansion provided useful information about urban patches. It was seen from these gradients of Mean Patch Size in urban class decreased from near the urban core to countryside and multiple peaks of MPS in new developed area. Results of Landscape Shape Index didn’t represent the same dramatic decrease in suburban areas. Fraction dimension of 1.76 reflects perfected infill capacity of urban growth when comparing the shape of largest urban patches across time. Furthermore, the potential cause might be low proportion of infilling growth or spontaneous growth and high proportion of edge growth. Based on the diffusion and coalescence hypothesis, it could be inferred that coalescence followed by the diffusion of 1996 towards a saturated urban landscape.Chapter six presented scale sensitivity of SLEUTH model (i.e. Slope, Landuse, Excluded, Urban extent, Transportation, Hillshade), simulated and evaluated different scenarios produced by SLEUTH. The exploration results of scale sensitivity of SLEUTH showed that spontaneous growth was overestimated due to a lot of undesirable factors and low-density development affected the calibration results when scaling up in spatial extent. So it was reasonable to reduce spread coefficient and define excluded layer in order to prohibit excessive growth. Then SLEUTH model was used to predict four future growth scenarios in Hangzhou, including Maintain Status Quo, Expanded Roads, Moderate Farmland Protection and Compact City. The alternative scenarios were assessed by the proposed aspects such as amount and spatial distribution of urban growth, and consistence with master plan. The results showed that urban growth in MSQ scenario would be faster than allowable amount of master plan or land use plan and farmland would be more fragmented. In particular, urban form would be compact through guiding urban development to hot-spot areas in ER. Furthermore, edge growth could be promoted by MFP and CC. Finally, abrupt policy change should be further considered in SLEUTH model in order to promote its accuracy.Above all, Chapter seven drew a conclusion and briefly discusseed policy implication, and also pointed out the shortcomings.更多还原