Analysis of subsidence change regularity in high‑groundwater‑level coal mining areas in different periods from Sentinel-1A time-series data

Abstract

Abstract The high‑groundwater‑level coal mining areas have a long history of mining and are mainly located in east-central region of China. Subsidence caused by coal mining has several different periods. However, the subsidence change regularity in each periods remains unclear. This study aimed at revealing the subsidence change regularity in high‑groundwater‑level coal mining areas in different periods. Juye mining area was selected for the study, which located in Heze City, Shandong Province, China. Firstly, 54 Sentinel-1A radar satellite images from August 2018 to July 2020 were acquired for this research. The “two-track method” of D-InSAR technology was employed to process of images. Secondly, based on subsidence velocity of 1.7 mm/day, the subsidence process was divided into three periods: initial, active and weakening. Thirdly, elevation data of ground levelling points were used to check the accuracy of subsidence monitoring using Sentinel-1A data. At last, the subsidence change process in different periods was analyzed and the change regularity was summarized. The results are shown as follows: (1) The subsidence characteristics are not obvious in initial period. (2) The subsidence funnel begin to form and the mean maximum subsidence in center is greater than 1400 mm in active period. (3) The subsidence rate and volume gradually decrease and eventually stabilize in weakening period. The results can provide an important basis for land conservation in mining areas.