Sub-national level administrative areas
This post documents an interesting source for sub-national level administrative areas, such as city-level shapefiles. This could be particularly useful when you are trying to downscale gridded data to city-level.
The database is GADM (Database of Global Administrative Areas). It provides maps and spatial data for all countries and their sub-divisions. You can browse our maps or download the data to make your own maps.
See an example of spatial data for China. Level-0, 1, 2, 3 stands for county level, province level, city level, and county level I guess. But you should double check that.
See the data package for more information in data format.
Dang and Trinh. Does the COVID-19 lockdown improve global air quality? New cross-national evidence on its unintended consequences. Journal of Environmental Economics and Management 105 (2021). Link