Unveiling 25 Years of Planetary Urbanization with Remote Sensing: Perspectives from the Global Human Settlement Layer
Unveiling 25 Years of Planetary Urbanization with Remote Sensing: Perspectives from the Global Human Settlement Layer
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DOI：
10.3390/rs10050768
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发表时间：
2018-05-01
期刊：
影响因子：
5
通讯作者：
Kemper, Thomas
中科院分区：
文献类型：
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作者：
Melchiorri, Michele;Florczyk, Aneta J.;Kemper, Thomas
在过去几十年中，科学家和决策者越来越清楚地看到全球城市变化的规模和影响。长期以来，从地域范围和比较能力来看，理解这些进程的能力仍然有限：数据的可得性和协调是主要的制约因素。现代技术资产，如遥感和机器学习，允许以前所未有的细节分析结算过程中的全球变化。全球人类住区层（GHSL）项目旨在生成详细的数据集，以分析和监测人类住区及其人口的空间足迹，这是2030年发展议程全球政策承诺的关键指标。在全球地球科学实验室中，地球观测在根据大地卫星图像探测建成区方面发挥着关键作用，而人口分布则是以该图像为基础的。遥感图像与人口建模相结合，可生成关于建成区和人口空间分布的全球一致的详细信息。GHSL数据有助于对全球范围的人类住区进行多时期分析。本文提出的结果集中在建成区，人口和住区的发展模式。本文报告了全球城市化的现状（2015年）及其自1990年以来的演变，并将欧洲委员会区域和城市政策总司（DG-Regio）和欧洲共同体统计局（EUROSTAT）的城市化程度定义应用于GHSL。该分析描绘了区域层面和每个国家收入阶层的城市化动态，以显示差异和不平等。这项研究分析了全球61亿城市居民的分布情况。结果显示了全球城市化程度（2015年达到85%），1990年至2015年期间城市化增长的100多个国家，以及城市化水平高于全球平均水平和城市化增长最快的数十个国家。该文件阐明了城市地区对发展的关键作用、世界各区域的城市发展模式以及新一代数据对推进城市化理论和报告的作用。
In the last few decades the magnitude and impacts of planetary urban transformations have become increasingly evident to scientists and policymakers. The ability to understand these processes remained limited in terms of territorial scope and comparative capacity for a long time: data availability and harmonization were among the main constraints. Contemporary technological assets, such as remote sensing and machine learning, allow for analyzing global changes in the settlement process with unprecedented detail. The Global Human Settlement Layer (GHSL) project set out to produce detailed datasets to analyze and monitor the spatial footprint of human settlements and their population, which are key indicators for the global policy commitments of the 2030 Development Agenda. In the GHSL, Earth Observation plays a key role in the detection of built-up areas from the Landsat imagery upon which population distribution is modelled. The combination of remote sensing imagery and population modelling allows for generating globally consistent and detailed information about the spatial distribution of built-up areas and population. The GHSL data facilitate a multi-temporal analysis of human settlements with global coverage. The results presented in this article focus on the patterns of development of built-up areas, population and settlements. The article reports about the present status of global urbanization (2015) and its evolution since 1990 by applying to the GHSL the Degree of Urbanisation definition of the European Commission Directorate General for Regional and Urban Policy (DG-Regio) and the Statistical Office of the European Communities (EUROSTAT). The analysis portrays urbanization dynamics at a regional level and per country income classes to show disparities and inequalities. This study analyzes how the 6.1 billion urban dwellers are distributed worldwide. Results show the degree of global urbanization (which reached 85% in 2015), the more than 100 countries in which urbanization has increased between 1990 and 2015, and the tens of countries in which urbanization is today above the global average and where urbanization grows the fastest. The paper sheds light on the key role of urban areas for development, on the patterns of urban development across the regions of the world and on the role of a new generation of data to advance urbanization theory and reporting.