Detection of Land Subsidence due to Excessive Groundwater Use Varying with Different Land Cover Types in Quetta valley, Pakistan Using ESA-Sentinel Satellite Data

Abstract. In this study, we show that land subsidence in Quetta valley, Pakistan is caused by exploitation of groundwater based on the analysis of European Space Agency (ESA) Sentinel satellite data. For this, we performed interferometry analysis using twenty nine Sentinel-1 SAR images to obtain twenty eight interferograms of land subsidence for the period between 16 Oct 2014 and 06 Oct 2016. Then, the land subsidence was compared with the land cover of the study area that was derived from Sentienl-2 multispectral images. The results reveal that, for the period of two years, the entire study area experienced highly uneven land subsidence with its magnitude ranging between 10 mm to 280 mm. The spatial pattern of land subsidence showed a high correlation with that of land covers. While urban and cultivated area with high groundwater extraction showed great amount of land subsidence, barren and seasonally cultivated area did not show as much land subsidence.