Deriving the ground deformation of the whole coal mining areas in Shanxi Province, China, by Wide-Area InSAR technology and ALOS-1 PALSAR data

Shanxi Province, a significant energy province in China, has been active underground coal mining for many years, coupled with the over-dependence of the local arid climate on groundwater, resulting in a large number of ground instability areas, which further breeds a series of geohazards. Scholars have studied the present ground instability in whole or local regions of Shanxi Province, but the understanding of the earlier deformation situation is insufficient. In this study, we recover the provincial-scale ground deformation in Shanxi between 2007 and 2010 for the first time, using all ALOS-1 PALSAR images from 1234 scenes and 67 frames via wide-area InSAR technology and a machine learning algorithm. There is good spatial consistency between the deformation rates in adjacent frames. We calculate the RMSE of the independent solution of two adjacent frame common areas, and the value is 2.4 mm/yr. The spatiotemporal distribution characteristics of the wide-area deformation during the monitoring period are analyzed in combination with the mining subsidence area (MSA) vector, geohydrology, optical remote sensing, and field survey in Shanxi. Between 2007 and 2010, we identified a total of 429 ground instability regions covering an area of 3,748.112 km². The spatial distribution of the deformation is highly consistent with that of MSA and plain agricultural regions. The MSA has a dense distribution of subsidence areas. In the plain areas represented by facility agriculture in the Taiyuan Basin and Yuncheng Basin, local surface deformation is more significant due to the greater demand for groundwater. The results of this study will provide basic data for ground stability surveys and government control in Shanxi Province and also serve as a reference for provincial or regional-scale InSAR deformation monitoring.