With the expansion of the built-up area, the vegetation coverage decreased by 16.61% (1652.56 km 2) (3) the land surface temperature shows an increment trend in the new town yet a decrement trend in the old town due to the change in vegetation coverage and the decentration of administration centers further analysis shows that the population and the social economy are two driving factors for land cover changes.

The results show that: (1) the classification accuracy is excellent the average overall accuracy is 93% and the Kappa coefficient is 0.88 (2) the general spatio-temporal variations in land cover in Hefei from 2000 to 2020 are obvious the built-up area expanded from 419.72 km 2 to 1530.20 km 2, with a total growth rate of 264.58%. In this study, with support from huge amounts of data (including 719 Landsat TM/ETM+/OLI satellite images, land surface temperature, nighttime satellite images, DEM, multiple land cover products, and various auxiliary data), processing and parallel computing abilities of the GEE platform, classification maps of land cover in Hefei from 2000 to 2020 are produced based on a random forest machine learning method, and the spatio-temporal variations and driving factors are analyzed from both global and local viewpoints. Thus, it is of great significance to monitor the land cover change for the city with the fastest economic growth in China based on the long time-series satellite images from both global and local perspectives. However, (1) many previous studies focus on the land cover change in metropolis or at the global scale, yet few focus on underdeveloped but fast-growing cities (2) land cover studies mainly focus on global variations, yet seldom on local characteristics. The high-speed economic development inevitably led to rapid changes in land cover types, e.g., an increment in artificial features (built-up) and decrement in natural features (vegetation). Hefei’s gross domestic product (GDP) growth rate ranks first among all cities in China, and it was the fastest-growing city in China from 2000 to 2020.

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