HR: 1340h
AN: H33F-0520    [Abstracts]
TI: Calibration of a Complex Three-Dimensional Coastal Aquifer with Density-Dependent Flow
AU: * Bray, B S
EM: bbray@ucla.edu
AF: UCLA, 5732 Boelter Hall, UCLA, Los Angeles, CA 90095 United States
AU: Sim, Y
EM: ysim@ladpw.org
AF: Department of Public Works, 900 S. Fremont Ave., Los Angeles, 91802 United States
AU: Yeh, W
EM: williamy@seas.ucla.edu
AF: UCLA, 5732 Boelter Hall, UCLA, Los Angeles, CA 90095 United States
AB: In Los Angeles County hydraulic barriers have been implemented in three coastal areas to reduce saltwater intrusion since the 1950s. Effective evaluation and operation of current barrier facilities is critical for protecting the future basin water supplies. Due to conservation concerns, and because of a general interest in improving the performance of the barriers in Los Angeles County, a modeling study has been initiated for one of the barrier sites. An open-source, fully three-dimensional finite element groundwater model has been selected to solve the coupled flow and mass transport equations. To ensure proper simulation of density-dependent flow and transport, the model was validated using Henry's problem and the output was quantitatively compared with standard published results. A modified kriging method was applied to estimate the heterogeneous intrinsic permeability distribution for each of the five aquifer layers, noting that a comparable level of detail could not be achieved with a more traditional inverse procedure. The model performance for the heterogeneous case was compared with a homogeneous case estimated by traditional inverse procedure. Furthermore, two calibration periods, one short term and one long term, were selected to fine tune the appropriate transport parameters. Typical monitoring intervals were biannual with a smaller subset of observation wells taking measurements of total head and chloride concentration on a monthly basis.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting