Quantifying the speed, growth modes, and landscape pattern changes of urbanization: a hierarchical patch dynamics approach
Quantifying the speed, growth modes, and landscape pattern changes of urbanization: a hierarchical patch dynamics approach
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DOI：
10.1007/s10980-013-9933-6
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发表时间：
2013-12-01
影响因子：
5.2
通讯作者：
Wu, Jianguo
中科院分区：
文献类型：
--
作者：
Li, Cheng;Li, Junxiang;Wu, Jianguo
城市化改变了景观结构，深刻影响了生物多样性和生态过程。为了理解和解决这些生态问题，至少需要量化城市化时空格局的三个方面：速度、城市增长模式以及由此产生的景观格局变化。在这项研究中，我们量化了这些时空格局的城市化在长江三角洲中部地区，中国从1979年至2008年，基于层次斑块动力学框架，指导研究设计和分析与景观指标。我们的研究结果表明，在研究区域的城市化面积呈指数增长，在县，地级市和区域层面的30年，随着城市等级的增加速度。三种增长模式填充，边缘扩展，跨越式的同时运作，其相对优势随着时间的推移而转移。随着城市化进程的推进，斑块密度和边缘密度普遍增加，城市斑块平均最近邻距离的连通性也增加。虽然斑块层次的结构复杂性也趋于增加，但单个斑块的形状变得越来越规则。我们的研究结果表明，城市景观是否变得更加同质或异质可能取决于时间和空间的规模以及景观指标。生长速度、生长方式和景观格局之间存在着复杂的关系。要更好地理解这种复杂的关系，就不能简单地将城市化概念化为一个二分法的扩散-聚合转换过程，而应将其视为一个在多种增长模式之间转移主导地位的螺旋式过程：填充、边缘扩张和跨越景观的兴衰。
Urbanization transforms landscape structure and profoundly affects biodiversity and ecological processes. To understand and solve these ecological problems, at least three aspects of spatiotemporal patterns of urbanization need to be quantified: the speed, urban growth modes, and resultant changes in landscape pattern. In this study, we quantified these spatiotemporal patterns of urbanization in the central Yangtze River Delta region, China from 1979 to 2008, based on a hierarchical patch dynamics framework that guided the research design and the analysis with landscape metrics. Our results show that the urbanized area in the study region increased exponentially during the 30 years at the county, prefectural, and regional levels, with increasing speed down the urban hierarchy. Three growth modes-infilling, edge-expanding, and leapfrogging-operated concurrently and their relative dominance shifted over time. As urbanization progressed, patch density and edge density generally increased, and the connectivity of urban patches in terms of the average nearest neighbor distance also increased. While landscape-level structural complexity also tended to increase, the shape of individual patches became increasingly regular. Our results suggest that whether urban landscapes are becoming more homogenous or heterogeneous may be dependent on scale in time and space as well as landscape metrics used. The speed, growth modes, and landscape pattern are related to each other in complicated fashions. This complex relationship can be better understood by conceptualizing urbanization not simply as a dichotomous diffusion-coalescence switching process, but as a spiraling process of shifting dominance among multiple growth modes: the wax and wane of infilling, edge-expansion, and leapfrog across the landscape.