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Confined aquifer head measurements and storage properties in the San Luis Valley, Colorado, from spaceborne InSAR observations
Author(s) -
Chen Jingyi,
Knight Rosemary,
Zebker Howard A.,
Schreüder Willem A.
Publication year - 2016
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1002/2015wr018466
Subject(s) - interferometric synthetic aperture radar , aquifer , geology , remote sensing , synthetic aperture radar , groundwater , structural basin , geomorphology , geotechnical engineering
Abstract Interferometric Synthetic Aperture Radar (InSAR), a remote sensing technique for measuring centimeter‐level surface deformation, is used to estimate hydraulic head in the confined aquifer of the San Luis Valley (SLV), Colorado. Reconstructing head measurements from InSAR in agricultural regions can be difficult, as InSAR phase data are often decorrelated due to vegetation growth. Analysis of 17 L‐band ALOS PALSAR scenes, acquired between January 2007 and March 2011, demonstrates that comprehensive InSAR deformation measurements can be recovered over the vegetated groundwater basin with an improved processing strategy. Local skeletal storage coefficients and time delays between the head change and deformation are estimated through a joint InSAR‐well data analysis. InSAR subsidence estimates are transformed to head changes with finer temporal and spatial resolution than is possible using existing well records alone. Both InSAR and well data suggest that little long‐term water‐storage loss occurred in the SLV over the study period and that inelastic compaction was negligible. The seasonal head variations derived from InSAR are consistent with the existing well data at most locations where confined aquifer pumping activity dominates. Our results demonstrate the advantages of InSAR measurements for basin‐wide characterization of aquifer storage properties and groundwater levels over agricultural regions.