Monitoring Three-Decade Expansion of China’s Major Cities Based on Satellite Remote Sensing Images

Abstract

As the largest developing country, China has experienced dramatic urban expansion since the “reform and opening-up” policy started at the end of the 1970s. In this paper, we monitor three decades of urban expansion in China’s 36 major cities, based on the spectral mixture analysis of remotely sensed satellite images. The results demonstrated that these major cities have expanded by 5.85 times from 1986 to 2015, with 15.51 km2 average expansion area per city per year. We found the urban expansion trajectories showed three different modes, i.e., exponential, linear and s-shaped, which were closely related to the city development level. In the old city zones, however, there was an interesting common tendency of the impervious surface area (ISA) first increasing and then decreasing, which could be largely attributed to the phenomenon of urban village reconstruction in China’s cities. Based on the Granger Causality Test (GCT), the interaction between urban ISA and Gross Domestic Product (GDP) per capita (GDPPC) suggested that the former was the driver of the latter. Meanwhile, taking the Yangtze River as the division between north and south China, there exists a north–south territorial differentiation for the interaction between ISA and total population at the year-end (TP).

Opposite Spatiotemporal Patterns for Surface Urban Heat Island of Two “Stove Cities” in China: Wuhan and Nanchang

“…The highest SUHII was shown in 2012 and the lowest SUHII was found in 2016. Referring to the temporal trend for ISA in OCZ gained from our previous research [54], in Nanchang, we detected an ISA evolution trend opposite to the SUHII evolution trend-first increasing, then decreasing. However, the SUHII trend in the time series was consistent with the ISA variation in OCZ in Wuhan.…”

“…Specifically, the water body is excluded from the SUHII calculation. For more information on water body exclusion, we refer to our previous research [54]. 1 RD is the reference pair dates.…”

“…The UC was defined as the city extent for each year. According to our previous research [54], we utilized LSMA to extract impervious surface area (ISA) for each year with the assistance of Landsat data. Next, the extracted ISA was aggregated into UC by city cluster algorithm [23,57,58].…”

“…After the exclusion of some misclassifications, the UC for Nanchang and Wuhan in each year was extracted. The urban area extraction part was done in our previous research [54].…”

Extraction and Spatio-Temporal Analysis of Impervious Surfaces over Dongying Based on Landsat Data

“…The impervious layer may also have a direct or indirect influence on many environmental factors, and changes in ISA ratios often directly coincide with urban development and expansion. Therefore, estimating and monitoring the distribution, development, and change in ISAs in urban areas have recently gained attention [15][16][17][18], particularly in developed countries [19]. The United States Geological Survey (USGS) has included impervious surface data in the second edition of its National Land Cover Database (NLCD), and, subsequently, has included impervious layer distribution survey data and research in the NLCD databases in 2006 and 2011 [20].…”