Chongqing: elevation is the main constraint
This sample ranges from about 122 to 2,230 meters in the generation report, a spread of roughly 2,108 meters. The difference is across the whole sampled area, not a claim that every neighborhood is steep.
Only 1.7% of cells are water-class cells, so the preview is more useful here for seeing changing ground height than for finding broad open water. A player can use it to compare flatter pockets with higher terrain before opening the game.
The downloadable grayscale image normalizes the land range for this sample. Its pixel brightness is therefore not an absolute height scale shared with another city.