The coordinated settlement patterns between loose aquifer loss and surface ground due to groundwater depletion

Abstract The displacement of groundwater resulting from mining disturbances and water withdrawals during coal production can lead to the compression of loose aquifers, leading to surface subsidence and threatening the safe production of coal mines. To thoroughly analyze the effects of non-mining factors on groundwater loss and subsidence in loose aquifers, the study area is divided into an aquifer system based on existing geological and hydrogeological data. A three-dimensional integrated subsidence observation network, designated the "sky-ground-underground" system, was constituted through the utilization of distributed fiber-optic sensor technology as the principal methodology. This approach was further enhanced through the integration of time-series InSAR technology, which was complemented by the utilization of conventional leveling, ground-based measurement techniques, and groundwater monitoring. The objective was to investigate the combined subsidence patterns of the strata and the surface. The findings suggest that the principal factor responsible for surface subsidence in the study area is the sustained compression of the fourth aquifer and the lower section of the third aquiclude. It has been observed that seasonal fluctuations in the deformation of the shallow aquifer occur. Furthermore, the weakening of clay in the deep-buried aquifer has been observed, with the degree of weakening correlating with groundwater mobility, thereby exacerbating surface subsidence. The compression observed in the fourth aquifer is primarily attributed to the loss of water from the aquifer. The study area has been observed to exhibit continuous surface sinking. The confirmation of a functional relationship between surface subsidence and the third aquiclude and fourth aquifers serves to reinforce the conclusion that declines in water levels in the fourth aquifer and the weakening of clay in the third aquiclude represent the primary factors contributing to surface subsidence.