The expansive soil, the same as the others in the Three Gorges Reservoir region, develops in the special geo-environment and with the Diluvial-to-Pluvial genesis and relatively uniform structure.

• 秭归县膨胀土与三峡其他地方的膨胀土一样发育于特殊的地质环境内，具有坡洪积成因和较均一土体结构。