改革开放以来，快速的城市化给社会、经济和环境带来了巨大的影响。为了研究城市化的成因和影响，许多学者提出了不同的指标来量化城市化过程。一方面，这些指标大多是从统计年鉴和普查数据中获取的，而这些数据存在连续性差、精确度低、空间信息少等问题，无法准确地描述城市化过程。另一方面，遥感图像包含丰富的关于城市形态、土地组成和社会经济的信息，可以很好地弥补传统数据的不足。因此，研究如何从遥感图像中提取城市化信息，并有效地用于城市化研究具有重要意义。 / 基于中国的城市化特点，本文分别从不同方面深入研究了从遥感图像中提取城市化指标的方法，并且通过这些指标分析了中国在过去二十年间的城市化发展特点。 / 首先，从社会经济发展的角度，本文分析了从夜晚灯光影像提取的遥感指标和社会经济学指标之间的时空关系。分析表明，城市内夜晚灯光的总量可以反映城市化的整体水平，而灯光覆盖区域的平均亮度可以较好反映城市化的总体强度，同时，灯光对城市化的响应会随着区域内亮度的增加而减弱。根据此灯光指标，我们发现在过去的二十年中，具有政治优势和地理优势的城市发展得更快。此外，与内陆其他地区相比，沿海地区的城市发展更加紧凑。 / 其次，从城市建成区面积的角度，本文提出了一种新的城市建成区提取方法，能够较准确地获取城市级的建成区序列。研究表明，从夜晚灯光影像中提取建成区时所选取的阈值会随年份和城市而变化，并且该阈值和城市的经济水平有显著的相关性。根据获取的建成区序列，我们研究了中国城市建成区的扩张特征，结果显示所有城市都表现出明显的扩张特征，该特征在沿海城市、省会城市和经济特区内尤其显著。 / 第三，从城市的空间结构变化角度，本文探讨了如何通过遥感影像量化城市的空间结构，以及如何利用这些量化信息来研究城市圈的发展过程。针对中国三大城市圈，本文比较了不同的遥感图像提取空间结构的特点，并且结合了景观生态学指数、帕雷托分布和梯度分析来研究城市圈内的城市之间的联系、分布和相互影响，发现不同城市圈的发展模式和驱动因素各有差异，具有很强的区域发展特点。 / 第四，从城市扩张形态的角度，本文从夜晚灯光影像中提取了两组指标来量化城市扩张程度。这两组指标分别从某一时间点的城市发展空间形态，以及一段时间内的城市增长模式来测量这一现象。结果显示，中国不同城市圈之间的城市扩张具有不同的特点。 / China has been undergoing rapid urbanization since the "open door" policy in 1978. The fast process of urbanization has significantly influenced its society, economy, and environment. To quantify and describe this process, various indicators of urbanization, which are usually extracted from statistical yearbook and census data, have been adopted. However, these data sets are usually inconsistent, problematic, and cannot depict the spatial information of urbanization. Therefore, remote sensing images are usually employed as complementary datasets. / However, the existing studies remain insufficient for understanding how the information of urbanization can be extracted from remote sensing imagery and used properly, especially for China, where urbanization has unique characteristics. Therefore, this thesis aims to explore the usage of remote sensing techniques to further observe the process of urbanization and from four different perspectives. / From the perspective of socioeconomic development, we analyze the spatial-temporal relationship between indicators derived from NTL images and the socio-economic indicators of urbanization. The results of the analysis indicate that the summed lights in a city can represent the overall level of urbanization and that the average light of lit-up areas can reflect the density of urbanization. Meanwhile, when the amount of NTL approaches saturation, it becomes a less sensitive reflection of the level of urbanization. The proper NTL indicator has then been utilized on the analysis of urbanization in China’s cities during the last 20 years, and the results reveal that the cities with political and geographical advantages have higher levels of urban development. Meanwhile, the cities in metropolitan areas and the Shandong province have undergone a more compact urbanization process than some inland cities. / Second, from the perspective of urban expansion, we extract the time series of urban built-up areas at the city level via a newly-proposed thresholding technique on the calibrated time series of NTL images. The threshold for extracting built-up areas has been found to vary across different cities and years, and it has high correlations with the level of economic development. We then analyze the urban expansion in Chinese cities based on prefecture cities in three provinces of south China. The results indicate that urban expansion occurred in all cities from 1992 to 2010, especially in coastal cities, capital cities, and cities in special economic zones. / Third, from the perspective of spatial pattern evolution, we explored how to quantify the urban spatial pattern, and use it to study the evolution of metropolitan areas. We compare the discrepancies of various remote sensing images in describing spatial patterns and combine the landscape metrics, Pareto distribution, and gradient analysis to explore growth type, distribution, and reaction of cities in metropolitan areas. Moreover, based on the comparison of the spatial patterns among three of the largest metropolitan areas of China during the last twenty years, we find that the driving force and growth type vary over metropolitan areas and that each area has its own regional characteristics. / Fourth, from the perspective of urban sprawl, we introduced two sets of indicators, which can measure urban sprawl both as a certain spatial pattern of urban development and as a type of urban growth, that quantify urban sprawl based on NTL imagery. The results present the degree of urban sprawl in various metropolitan areas in China. / Overall, this thesis extends our understanding on how to use information derived from remote sensing as a proxy for studies on urbanization. Moreover, urbanization in China is scrutinized by remote sensing indicators. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Liu, Lu. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 172-190). / Abstracts also in Chinese.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_1077639 |
| Date | January 2014 |
| Contributors | Liu, Lu , active 2014 (author.), Leung, Yee , 1948- (thesis advisor.), Chinese University of Hong Kong Graduate School. Division of Geography and Resource Management, (degree granting institution.) |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography, text |
| Format | electronic resource, electronic resource, remote, 1 online resource (xvii, 18-190 leaves) : illustrations (some color), maps (some color), computer, online resource |
| Coverage | China |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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