Time series interferometry integrated with groundwater depletion measurement from grace

摘要

This paper reports the findings based on ALOS-1 and GRACE satellite data for the purpose of monitoring land surface subsidence due to groundwater extraction in the Ordos Basin, China. Twenty ALOS-1 PALSAR data acquired between 8 January 2007 and 19 January 2011 are utilized in the time-series InSAR interferometry (TS-InSAR) analysis while the total water storage observations derived from the Gravity Recovery and Climate Experiment (GRACE) satellite data are integrated with hydrological modeling results (for soil moisture modelling) to estimate the groundwater depletion rate. The outcome shows that the total mean subsidence measured from TS-InSAR is about -6.8 mm yr-1 in vertical direction while the groundwater depletion rate is about -4.2 mm yr-1 between 17 December 2006 and 15 December 2010. Since in general every 1 m drop in groundwater level could lead to land subsidence of about 5 to 50 mm, and the total subsidence in Ordos Basin is mainly due to groundwater extraction and underground mining activities. The experiment result shows that the total land subsidence is mainly induced by underground mining.