1. High-spatiotemporal-resolution mapping of global urban change from 1985 to 2015
- Author
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Zhenzhong Zeng, Xuecao Li, Xiaoping Liu, Philippe Ciais, Yimin Chen, Yinghuai Huang, Kangning Huang, Guohua Hu, Xia Li, Xiaocong Xu, Peng Gong, Qiusheng Wu, Peirong Lin, Anping Chen, Jun Chen, Kai Gong, Lyndon Estes, Alan D. Ziegler, Shaojian Wang, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Agence Nationale de la Recherche, ANR Southern University of Science and Technology, SUSTech 2017YFA0604404, 2019YFA0607203, This research was funded by the National Key R&D Program of China (grant no. 2017YFA0604404 and grant no. 2019YFA0607203). Z.Z. was supported by the start-up fund provided by Southern University of Science and Technology (grant no. G02296001). We thank the French ANR Convergence Institute CLAND project for support. We thank many students (for example, Z. Lin) for their days and nights validating our GAUD product via high-resolution satellite image interpretation. We also thank K. C. Seto and M. Hansen for their constructive comments on this paper., ANR-16-CONV-0003,CLAND,CLAND : Changement climatique et usage des terres(2016), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
- Subjects
010504 meteorology & atmospheric sciences ,Environmental change ,Geography, Planning and Development ,Population ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Urban planning ,Urbanization ,Natural hazard ,11. Sustainability ,Population growth ,education ,0105 earth and related environmental sciences ,Nature and Landscape Conservation ,Sustainable development ,Global and Planetary Change ,education.field_of_study ,Ecology ,Flood myth ,Renewable Energy, Sustainability and the Environment ,business.industry ,Environmental resource management ,15. Life on land ,Urban Studies ,Geography ,13. Climate action ,[SDU]Sciences of the Universe [physics] ,business ,Food Science - Abstract
High-resolution global maps of annual urban land coverage provide fundamental information of global environmental change and contribute to applications related to climate mitigation and urban planning for sustainable development. Here we map global annual urban dynamics from 1985 to 2015 at a 30 m resolution using numerous surface reflectance data from Landsat satellites. We find that global urban extent has expanded by 9,687 km2 per year. This rate is four times greater than previous reputable estimates from worldwide individual cities, suggesting an unprecedented rate of global urbanization. The rate of urban expansion is notably faster than that of population growth, indicating that the urban land area already exceeds what is needed to sustain population growth. Looking ahead, using these maps in conjunction with integrated assessment models can facilitate greater understanding of the complex environmental impacts of urbanization and help urban planners avoid natural hazards; for example, by limiting new development in flood risk zones. The world keeps urbanizing. This study finds that since 1985 global urban lands have expanded four times faster than previously recognized and faster than population is growing.
- Published
- 2020