HR: 12:05h
AN: H42B-08    [Abstracts]
TI: Determination of Aquifer and Fault Permeabilities by Studying the Poroelastic Response of Rocks Using InSAR in the Upper Coachella Valley Area, CA, USA
AU: * Appana, R
EM: appan002@umn.edu
AF: University of Minnesota, 310 Pillsbury Dr. S.E. 108 Pillsbury Hall, minneapolis, MN 55455, United States
AU: Saar, M O
EM: saar@umn.edu
AF: University of Minnesota, 310 Pillsbury Dr. S.E. 108 Pillsbury Hall, minneapolis, MN 55455, United States
AB: Coachella Valley in California is an area enclosed between Little Bernardino, San Jacinto, and San Bernardino Mountains. The San Andreas Fault system runs through the valley. Satellite interferometry (InSAR) has revealed a differential uplift of the land surface over a period of time across two basin-cutting faults, the Banning Fault (BF) and the Garnet Hill Fault (GHF), in the upper Coachella valley region. This uplift is due to a combined effect of both elastic response of the aquifer due to groundwater recharge at the White Water Spreading Facility and tectonic stresses in the region (Wisely et. al., AGU 2006). In this region, faults appear to act as semi-permeable barriers to groundwater flow (Wisely et. al., AGU 2005). As a result, water levels are not restored uniformly throughout the entire aquifer leading to differential uplift of the land surface. Hence, by developing a numerical model of groundwater flow in this aquifer system, that includes hydraulic representations of the existing faults, a better water management strategy can be achieved which aims at restoring the groundwater levels throughout the aquifer. In addition, the proposed model would better constrain fault permeabilities with implications for research related to earthquake dynamics and assessment of potential slip along segments of the San Andreas Fault system. A finite element code is being used to implement the groundwater flow model. The model simulates the poroelastic response of the faulted aquifer to changing groundwater levels. InSAR data and well data collected in this region will be used to constrain the model yielding parameters such as the hydraulic conductivity field of the aquifer and fault system, storage co-efficients, skeletal compressibilities, and the grounwater influx, and outflux, of the basin.
DE: 1822 Geomechanics
DE: 1829 Groundwater hydrology
DE: 1835 Hydrogeophysics
SC: Hydrology [H]
MN: 2007 Fall Meeting