Acta Geographica Sinica ›› 2018, Vol. 73 ›› Issue (12): 2345-2363.doi: 10.11821/dlxb201812006

• Urban and Regional Development • Previous Articles     Next Articles

High accuracy urban expansion monitoring and analysis of China's provincial capitals from 2000 to 2015 based on high-resolution remote sensing imagery

ZHANG Hanchao1,2,3(),NING Xiaogang2,WANG Hao2(),SHAO Zhenfeng4   

  1. 1. School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430072, China
    2. Chinese Academy of Surveying and Mapping, Beijing 100830, China
    3. Beijing Key Laboratory of Urban Spatial Information Engineering, Beijing 100038, China
    4. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China
  • Received:2017-11-29 Online:2018-12-14 Published:2018-12-14
  • Supported by:
    The National Key Research and Development Program of China, No.2016YFE0205300;National Natural Science Foundation of China, No.41401513;Fundamental Research Funds for the Central Public-Interest Scientific Institution, No.7771803;Funded by Beijing Key Laboratory of Urban Spatial Information Engineering, No.2018202

Abstract:

China has undergone a rapid urbanization since the beginning of the 21st century. Urban expansion monitoring has become a hotspot in the field of geographical science. However, methods of urban boundary extraction were inconsistent, and the precision of previous urban boundary products is relatively low due to the coarse image resolution. In this paper, a method of high-precision and unified urban expansion monitoring and analysis of China's 31 provincial capitals was carried out based on high-resolution remote sensing images. First, the urban boundaries of 2000, 2005, 2010 and 2015 were extracted with a series of unified rules by urban landscape characteristics and geographical knowledge based on high-resolution images. Then, urban boundary result was compared with other urban boundary products based on low and mid-resolution images to assess the accuracy. Finally, urban size distribution and urban expansion were analyzed based on urban area and urban boundary results. Results showed that the proposed method of urban boundary extraction was superior to other researches. From 2000 to 2015, China's provincial capitals witnessed a rapid growth trend, and the total urban area increased by 90.15%; the provincial capitals system approximated size distribution of the rank-size law. Urban expansion had a significant regional difference. Urban expansion rate in the eastern region gradually slowed down, while that in the western and northeastern regions had an accelerating mode, and that in the central region expanded steadily. Beijing, Tianjin, Shanghai, Guangzhou and Chongqing, which were designated as the national central cities in 2010, ranked the top five of urban area size in 2015. The five cities increased by 82.45% during the 15 years, and the average annual urban expansion area was 30.66 km2. Urban area of Beijing, Tianjin, Shanghai, Guangzhou and Chongqing increased by about 30%, 100%, 100%, 60% and 200%, respectively. This research provides unified and high-precision spatial urban boundaries data and urban expansion results for local governments and the public, which are useful for scientific urban development and planning of China's urban system.

Key words: urban expansion, high-resolution image, urban area, provincial city, rank-size law