Predictability of hydraulic head changes and characterization of aquifer‐system and fault properties from InSAR‐derived ground deformation

Abstract

We evaluate the benefits of space-derived ground deformation measurements for basin-wide characterization of aquifer-system properties and groundwater levels. We use Interferometric Synthetic Aperture Radar (InSAR) time series analysis of ERS, Envisat, and ALOS SAR data to resolve 1992-2011 ground deformation in the Santa Clara Valley, California. T-mode principal component analysis successfully isolates temporally variable deformation patterns embedded in the multidecadal time series. The data reveal uplift at 0.4 cm/yr between 1992 and 2000 and < 0.1 cm/yr during 2000-2011, illustrating the end of the aquifer-system's poroelastic rebound following recovery of hydraulic heads after the 1960s low stand. In addition, seasonal elastic deformation with amplitude of up to 3 cm, in phase with head fluctuations, is observed over the confined aquifer sharply partitioned by the Quaternary Silver Creek Fault (SCF). Integration of this deformation with hydraulic head data enables characterization of the aquifer-system storativity and elastic skeletal specific storage. Modeling of the deformation partitioning across the SCF constrains the fault's last tectonic activity, hydraulic conductivity, and material composition. The SCF likely cuts the shallow confining clays and was last active since~140 ka, it has a horizontal hydraulic conductivity several orders of magnitude lower than the surrounding aquifer-system, and is likely composed of clays, making it an effective barrier to across-fault fluid flow. Finally, we show that after a period of calibration, InSAR can be used to characterize basin-wide water level changes without well measurements with an accuracy of 70%, which demonstrates that it provides useful data for groundwater management.

Characterization of Black Sand Mining Activities and Their Environmental Impacts in the Philippines Using Remote Sensing

“…This larger extent of the subsiding areas likely reflects groundwater usage or sediment redistribution around the affected areas. We also notice that the spatial extent of the subsiding areas associated with the black sand mining sites is small compared to the extent of the land subsidence associated with other processes such as ground water extraction, e.g., [13][14][15]; oxidation of peatlands, e.g., [31]; natural sediment compaction e.g., [32]; slope motion e.g., [33]; sinkholes e.g., [34]; and hydrothermal or magmatic activity, e.g., [12,35]. Thus, the small spatial extent of the land subsidence associated with black sand mining activities can be used to detect black sand mining sites and isolate this process from others.…”

“…InSAR has been used to successfully detect ground deformation associated with a number of geohazards, from earthquakes, to volcanic eruptions and land subsidence due to groundwater extraction [8][9][10][11][12][13][14][15]. Here, we test whether the mining activities result in any detectable ground deformation despite their small spatial extent and evaluate for the first time the environmental effects of black sand mining with a high spatial resolution.…”

Land subsidence, Ground Fissures and Buried Faults: InSAR Monitoring of Ciudad Guzmán (Jalisco, Mexico)

“…In some places, this kind of land subsidence is associated with structural faults, generating fissures and surface faults due to vertical differential compaction of lacustrine and/or fluvio-lacustrine sediments overlying the faults [45,46]. This phenomenon is called Subsidence-Creep-Fault Process (SCFP) [18,46] and is characterized by different stages.…”

“…In fact, the aquifer of CG is formed by alternating levels of sandy to gravelly layers (acquifers) and silty to clayey levels (aquitards) [32,37]. Furthermore, an important drop of piezometric water level has been reported in CG and in other Mexican cities [45,48]. In particular, CG has experienced a reduction in the phreatic level of about 69 cm per year [37].…”

Methodology for Detection and Interpretation of Ground Motion Areas with the A-DInSAR Time Series Analysis

“…A-DInSAR measurements represent the cumulative ground movements (natural versus anthropic, superficial versus deep displacements, multi-year, and seasonal components); the overlapping of several ground motion components may make the accurate interpretation of ground deformation processes difficult. Recent studies have applied PCA to satellite-based time series analysis [39,40] to detect spatio-temporal deformation patterns.…”