《The dynamics of poor urban areas - analyzing morphologic transformations across the globe using Earth observation data》

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作者
Nicolas J. Kraff;Michael Wurm;Hannes Taubenböck
来源
CITIES,Vol.107,Issue1,Article 102905
语言
英文
关键字
Urban morphology;Urban pattern;Change detection;Slums;Informal settlements;Urban poverty;3D city model;Remote sensing;Earth observation
作者单位
German Aerospace Center, Earth Observation Center, German Remote Sensing Data Center, Georisks & Civil Security, Oberpfaffenhofen, 82234 Wessling, Germany;University of Wuerzburg, Institute of Geography, Department of Remote Sensing, Am Hubland, Oswald Kuelpe Weg 86, Wuerzburg 97074, Germany;German Aerospace Center, Earth Observation Center, German Remote Sensing Data Center, Georisks & Civil Security, Oberpfaffenhofen, 82234 Wessling, Germany;University of Wuerzburg, Institute of Geography, Department of Remote Sensing, Am Hubland, Oswald Kuelpe Weg 86, Wuerzburg 97074, Germany
摘要
The urban environment is in constant motion, mostly through construction but also through destruction of urban elements. While formal development is a process with long planning periods and thus the built landscape appears static, informal or spontaneous settlements seem to be subject to high dynamics in their ever unfinished urban form. However, the dynamics and morphological characteristics of physical transformation in such settlements of urban poverty have been hardly empirically studied on a global scale or temporal consistent foundation. This paper aims at filling this gap by using Earth observation data to provide a temporal analysis of built-up transformation over a period of ~7 years in 16 documented manifestations of urban poverty. This work applies visual image interpretation using very high resolution optical satellite data in combination with in-situ- and Google Street View images to derive 3D city models. We measure physical spatial structures through six spatial morphologic variables - number of buildings, size, height, orientation, heterogeneity and density. Our temporal assessment reveals inter- as well intra-urban differences and we find different, yet generally high morphologic dynamic across study sites. This is expressed in manifold ways: from demolished and reconstructed areas to such where changes appeared within the given structures. Geographically, we find advanced dynamics among our sample specifically in areas of the global south. At the same time, we observe a high spatial variability of morphological transformations within the studied areas. Despite partly high morphologic dynamics, spatial patterns of building alignments, streets and open spaces remain predominantly constant.