Hawaii Commission on Water Resources Management (CWRM)
2006 - 2008
Basal aquifers, in which freshwater floats on top of saltwater, are the major freshwater supply for the Hawaiian Islands, as well as many other coastal regions around the world. Under unexploited or natural conditions, freshwater and the underlying seawater are separated by a relatively sharp interface located below mean sea level at a depth of about 40 times the hydraulic head. With forced draft, the hydraulic head of a basal aquifer would decline and the sharp interface would move up. It is a serious problem of seawater intrusion as huge amounts of freshwater storage is replaced by saltwater. Also, with forced draft, the sharp interface is replaced by a transition zone in which the salinity increases downward from freshwater to saltwater. As pumping continues, the transition zone expands. The desirable source-water salinity in Hawaii is about 2% of the seawater salinity. Therefore, the transition zone expansion is another serious problem of seawater intrusion. In this study, a robust analytical groundwater flow and salinity transport model (RAM2) was developed. RAM2 has a simple mathematical structure and its model parameters can be determined satisfactorily with the available field monitoring data. The usefulness of RAM2 as a viable management tool for coastal ground water management was demonstrated by applying it to determine the sustainable yield of the Pearl Harbor aquifer, a principal water supply source in Hawaii.
Liu, Clark C.K., and John J. Dai. 2012. Seawater intrusion and sustainable yield of basal aquifers. Journal of the American Water Resources Association Paper No. JAWRA-10-0193-P, pp. 1–10 (Published 2012; discussions are open until six months from print publication). Print publication: 48(5):861–870, Published October 2012. DOI:10.1111/j.1752‐1688.2012.00659.x
Liu, C.C.K., and X. Li. 2007. Analytical groundwater modeling for estimating sustainable yield of Iao Aquifer, Maui, Hawaii. In Proceedings of the World Environmental and Water Resources Congress 2007: Restoring Our Natural Habitat, ed. Karen C. Kabbes, 10 pp. Publisher: American Society of Civil Engineers.
Liu, Clark C.K., John F. Mink, and John Jun Dai. 2005. Simple analytical groundwater modeling for sustainable yield estimates. In Institutions for Sustainable Watershed Management: Reconciling Physical and Management Ecology in Asia–Pacific (AWRA 2005 summer specialty conference), eds. Jason K. Levy, James E.T. Moncur, Clark Liu, and Charles F. Ice, CD-ROM (6 pp.). American Water Resources Association, Middleburg, VA.
Liu, C.C.K. 2007. RAM2 modeling and the determination of sustainable yields of Hawaii basal aquifers. Project Report PR-2008-06. Water Resources Research Center, University of Hawaii at Manoa, Honolulu, Hawaii.