The results of this study show that (1) since 2012, the proportion of shallow-layer (≤ 82 m) compression and settlement contribution has gradually decreased, while the proportion of deep-layer (> 82 m) compression has significantly increased; (2) during the deformation process of layered soil, the amount of compression is closely related to the change of groundwater level; and (3) the shallow, middle and deep strata show obvious viscoelastic–plastic deformation characteristics on the whole.

This article established a groundwater–subsidence model in a typical land subsidence region and classified an early land subsidence warning zone based on the results from the model. If the pumping of groundwater from the second and fourth aquifers was reduced by 50 % and pumping from the third aquifer was reduced by 60 %, the early warning level for land subsidence would be greatly reduced and would meet the requirements for land subsidence control.

The results indicated that The surface location of Gaoliying fissure is controlled by the underlying normal fault activity, and over pumping further exacerbates development of the ground fissure; when the groundwater level declines, obvious differential settlement occurs at both sides of the ground fissure. The fault activity contributes about 28-39 percent, and the groundwater contributes about 61-72 percent to the deformation of the ground fissure, respectively.