HR: 0800h
AN: H21C-0696    [Abstracts]
TI: Estimating Hydraulic Properties of Coastal Aquifers Using Wave Setup
AU: * Rotzoll, K
EM: kolja@hawaii.edu
AF: University of Hawaii at Manoa, Dept of Geology and Geophysics, Water Resources Research Center, 1680 East-West Road, Honolulu, HI 96822, United States
AU: El-Kadi, A I
EM: elkadi@hawaii.edu
AF: University of Hawaii at Manoa, Dept of Geology and Geophysics, Water Resources Research Center, 1680 East-West Road, Honolulu, HI 96822, United States
AB: Wave setup is associated with the momentum transfer of breaking waves to the water column, which results in an elevated mean water table at the coast over several days. Groundwater responses to setup were observed as far as 5 km inland in a coastal aquifer in central Maui, Hawaii. Results showed that setup pulses dominate over barometric pressure effects on low-frequency groundwater fluctuations during times of energetic swell events. Matching peak frequencies in setup and observed head were identified. As is the case with tides, the setup propagation through the aquifer shows exponentially decreasing amplitudes and linearly increasing time lags. Setup was used to estimate a mean aquifer diffusivity of 2.3 x 10⁷ m²/d. The results agree with parameters estimated using aquifer tests and tides. A one-dimensional numerical model verified the results of the estimated parameters. The methodology is expected to be applicable to high-permeability coastal environments, such as volcanic islands and atolls.
DE: 1828 Groundwater hydraulics
DE: 1829 Groundwater hydrology
DE: 3285 Wave propagation (0689, 2487, 4275, 4455, 6934)
DE: 4217 Coastal processes
DE: 5144 Wave attenuation
SC: Hydrology [H]
MN: 2007 Fall Meeting