Abstract
The Tibetan Plateau (TP) is an important area that affects global sustainable development. Quantifying spatiotemporal patterns of urbanization is crucial for maintaining the sustainability on the TP. This study took Xining City, the largest city on the TP, as an example to understand the urban expansion in this region in the past 50 years. We combined the high-resolution spy satellite data and China’s long-term urban land dataset (CULD) to quantify the urban expansion of Xining City. The object-oriented random forest classification was performed to extract urban land from spy satellite data in 1969, and the inter-annual correction was used to combine urban land information from 1969 to 2017. We found that the proposed approach can accurately quantify the urban expansion of Xining City over the past half century with an overall accuracy of 91% and a kappa coefficient of 0.86. Such high accuracy benefits from the fine resolution of spy satellite data and the consistency of CULD. We also found that Xining City experienced accelerated and fragmented urban sprawl to higher altitude areas, as a result of socioeconomic development and topographical limitations. The acceleration of urban expansion was more obvious, and the urban landscape fragmentation was more serious at high altitude areas. Such urban expansion encroached on cropland and grassland, and caused increased risks of landslides and other geological disasters. Therefore, Xining City urgently needs to promote the development of compact cities to control urban sprawl at higher altitude areas and provide a reference for improving urban sustainability across the TP. In this study, we analyzed the urban expansion of Xining city from 1969 to 2017, and provided a reliable way to understand the long-term spatiotemporal urbanization based on remote sensing, which has the potential for wide applications. In addition, the extracted urban information can help to improve the urban sustainability of Xining City and the entire TP.
Highlights
The Tibetan Plateau (TP), known as the “Roof of the World”, “Water Tower ofAsia” and “Third Pole”, is perceived as an important ecological security barrier, a strategic resource reserve base and a protected place for Tibetan cultural heritage [1,2], which is an important area that influence global sustainable development [3]
Understanding the characteristics of urban expansion (UE) on the TP is the basis for optimizing the spatiotemporal pattern of urban land, which is important for promoting sustainable development on the TP
Whilst the area of Xining City only accounts for 0.3% of the area of the TP, its urban population is about 22.7% of the total urban population of the entire TP, its gross domestic product (GDP) accounts for 26.9% of the TP’s GDP [8], and its urban land area accounts for 19.3% of the total urban land area on the TP [9]
Summary
Asia” and “Third Pole”, is perceived as an important ecological security barrier, a strategic resource reserve base and a protected place for Tibetan cultural heritage [1,2], which is an important area that influence global sustainable development [3]. Understanding the characteristics of urban expansion (UE) on the TP is the basis for optimizing the spatiotemporal pattern of urban land, which is important for promoting sustainable development on the TP. With the rapid socioeconomic development, Xining City has become the city with the largest population, the highest gross domestic product (GDP) and the largest urban land area on the TP [7]. Since Xining City represents a typical city on the TP, quantifying the spatiotemporal pattern of UE in Xining City may provide a scientific basis to promote its healthy development and understand the characteristics of UE on the TP
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.
