Abstract
Rapid urbanization has occurred in northwestern China, threatening the sustainability of its fragile dryland ecosystems. A lack of precise urban land-cover information has limited our understanding on the urbanization in the dryland. Here, we examined urban land-cover changes from 2000 to 2014 in 21 major cities that comprise over 50% of the developed land in arid China, using Landsat Enhanced Thematic Mapper Plus and Operational Land Imager data, and a hybrid classification method. The 15-m resolution urban land-cover products (including impervious surfaces, vegetation, bare soil, and water bodies) had an overall accuracy of 90.37%. Based on these new land use products, we found the urbanization in arid China was characterized by the dramatic expansion of impervious surface (+13.23%) and reduction of bare soil (−13.41%), while the proportions of vegetation (+0.27%) and water (−0.10%) remained stable. The observed dynamic equilibrium of vegetated ratio implies an increasing harmonization of urbanization and greening, which was particularly important for the sustainability of fragile urban ecosystems in arid regions. From an economic perspective, gross domestic product and population were significantly correlated with impervious surfaces, and oasis cities displayed a stronger ability to attract new residents than desert cities.
Highlights
low-albedo and soil difference index (LSDI) and modified normalized difference water index (MNDWI) were used to improve the classification accuracy, the producer’s accuracy and user’s accuracy for bare soil were still the lowest compared to the other land-cover types
These results differed from the findings obtained by Yan et al (2015) [23], who indicated that ISA increased and green vegetation (GV) decreased in the city of Urumqi
Many studies that analyse dynamic urban land-cover characteristics were based on fixed areas [43,48,49], while the results reported in this paper considered changes to the built-up areas and provide more detailed information
Summary
As of 2008, more than half of the world’s population lived in urban areas [1]. This number is expected to reach 66 percent by 2050, and this ongoing increase is driving the rapid expansion of urban areas [2]. By 2030, the area of the world covered by urban land. Urban land-cover information has become an indicator of the ecological environment and climatic effects over different spatial and temporal scales [9,10,11,12]. Analysing the land-cover dynamics associated with urbanization in arid China represents a potential avenue for research regarding the impact of urbanization on the global environment [12,13,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
