Abstract:
Revealing the spatio-temporal response relationship between land subsidence and groundwater level variations in arid regions is crucial for the precise prevention and control of land subsidence. Based on Sentinel-1A radar imagery from 2017 to 2022, this study uses the PS-InSAR technique, continuous wavelet transform (CWT), cross-wavelet transform (XWT), and Moran’s I index to systematically analyze the spatial-temporal response relationship between land subsidence and groundwater level variations in the plain area of Hutubi County on the northern slope of the Tianshan Mountains. The results show that: (1) Significant land subsidence occurs in the plain area of Hutubi County from 2017 to 2022, with a maximum annual subsidence rate of -98.83 mm/a and a maximum cumulative subsidence of 196 mm. Two subsidence funnels are developed with a total area of 1,016 km
2, and the subsidence intensity is dominated by slight to moderate subsidence with an overall increasing trend.(2) Land subsidence and groundwater level variations present a significant temporal correlation, and show a lag response of 89.1~138.2 days within the common oscillation period of about one year.(3) Spatially, land subsidence and groundwater level variations show a weak positive correlation as a whole, while a synchronous change is observed in areas with high intensive exploitation, indicating that excessive groundwater exploitation is the main factor inducing land subsidence. This study reveals the coupling relationship between land subsidence and groundwater level variations in arid regions from the perspective of spatial-temporal response, which provides a scientific basis for the comprehensive prevention and control of land subsidence and groundwater resource management in arid regions.