Publications
Filter Total Items: 202
Trends and shifts in streamflow in Hawaii, 1913-2008
This study addresses a need to document changes in streamflow and base flow (groundwater discharge to streams) in Hawai'i during the past century. Statistically significant long-term (1913-2008) downward trends were detected (using the nonparametric Mann-Kendall test) in low-streamflow and base-flow records. These long-term downward trends are likely related to a statistically significant downward
Authors
Maoya Bassiouni, Delwyn S. Oki
Measurements of seepage losses and gains, East Maui Irrigation diversion system, Maui, Hawaiʻi
The U.S. Geological Survey conducted a field study from March to October 2011 to identify ditch characteristics and quantify seepage losses and gains in the East Maui Irrigation (EMI) diversion system, east Maui, Hawaiʻi. The EMI diversion system begins at Makapipi Stream in the east and ends at Māliko Gulch in the west. It consists of four primary ditches known as the Wailoa, New Hāmākua, Lowrie,
Authors
Chui Ling Cheng
Sources of suspended sediment in the Waikele watershed, Oʻahu, Hawaiʻi
Data from streamflow/sediment gages and measurements of changes in channel-bed sediment storage were gathered between October 1, 2007, and September 30, 2010, to assess the sources of suspended sediment in the Waikele watershed, Oʻahu, Hawaiʻi. Streamflow from the watershed averaged 33 cubic feet per second during the study period, with interannual variations corresponding with variations in the f
Authors
Scot K. Izuka
Groundwater availability in the Lahaina District, west Maui, Hawai'i
Most of the public water supply in the Lahaina District, west Maui, Hawai'i, is pumped from a freshwater lens in volcanic rocks. Because of population growth, groundwater withdrawals from wells in this area are expected to increase from about 5.8 million gallons per day in 2007 to more than 11 million gallons per day by 2030. Currently (2011), the salinity of water pumped from some of the wells in
Authors
Stephen B. Gingerich, John A. Engott
A water-budget model and estimates of groundwater recharge for Guam
On Guam, demand for groundwater tripled from the early 1970s to 2010. The demand for groundwater is anticipated to further increase in the near future because of population growth and a proposed military relocation to Guam. Uncertainty regarding the availability of groundwater resources to support the increased demand has prompted an investigation of groundwater recharge on Guam using the most cur
Authors
Adam G. Johnson
Numerical simulation of flow in deep open boreholes in a coastal freshwater lens, Pearl Harbor Aquifer, O‘ahu, Hawai‘i
The Pearl Harbor aquifer in southern O‘ahu is one of the most important sources of freshwater in Hawai‘i. A thick freshwater lens overlays brackish and saltwater in this coastal aquifer. Salinity profiles collected from uncased deep monitor wells (DMWs) commonly are used to monitor freshwater-lens thickness. However, vertical flow in DMWs can cause the measured salinity to differ from salinity in
Authors
Kolja Rotzoll
A water-budget model and assessment of groundwater recharge for the Island of Hawai'i
Concern surrounding increasing demand for groundwater on the Island of Hawaiʻi, caused by a growing population and an increasing reliance on groundwater as a source for municipal and private water systems, has prompted a study of groundwater recharge on the island using the most current data and accepted methods. For this study, a daily water-budget model for the entire Island of Hawaiʻi was devel
Authors
John A. Engott
Potential effects of roadside dry wells on groundwater quality on the Island of Hawai'i — Assessment using numerical groundwater models
Widespread use of dry wells to dispose of roadside runoff has raised concern about the potential effects on the quality of groundwater on the Island of Hawai‘i. This study used semi-generic numerical models of groundwater flow and contaminant transport to assess the potential effect of dry wells on groundwater quality on the Island of Hawai‘i. The semi-generic models are generalized numerical grou
Authors
Scot K. Izuka
Recent storm and tsunami coarse-clast deposit characteristics, southeast Hawai'i
Deposits formed by extreme waves can be useful in elucidating the type and characteristics of the depositional event. The study area on the southeast coast of the island of Hawaiʻi is characterized by the presence of geologically young basalts of known age that are mantled by recent wave-derived sedimentary deposits. The area has been impacted by large swells, storms and tsunamis over the last cen
Authors
B. M. Richmond, Sebastian Watt, M. Buckley, B. E. Jaffe, G. Gelfenbaum, R.A. Morton
Hydrogeology of the Hawaiian islands
Volcanic-rock aquifers are the most extensive and productive aquifers in the Hawaiian Islands. These aquifers contain different types of groundwater systems depending on the geologic setting in which they occur. The most common groundwater systems include coastal freshwater-lens systems in the dike-free flanks of the volcanoes and dike-impounded systems within the dike-intruded areas of the volcan
Authors
Stephen B. Gingerich, Delwyn S. Oki
Groundwater availability study for Guam; goals, approach, products, and schedule of activities
An expected significant population increase on Guam has raised concern about the sustainability of groundwater resources. In response, the U.S. Geological Survey (USGS), in collaboration with the University of Guam's Water and Environmental Research Institute of the Western Pacific (WERI) and with funding from the U.S. Marine Corps (USMC), is conducting a 3.5-year study to advance understanding of
Authors
Stephen B. Gingerich, John W. Jenson
Streamflow, suspended-sediment, and soil-erosion data from Kaulana and Hakioawa watersheds, Kaho'olawe, Hawai'i, 2006 to 2010
Various events over the last two centuries have destroyed the vegetation and caused rapid soil erosion on large areas of the small, arid, windy tropical shield-volcano island of Kaho`olawe, Hawai`i. These activities were largely halted in the 1990s, and efforts have been made to restore the island's vegetation in order to stem erosion. In 2003, the Kaho`olawe Island Reserve Commission (KIRC) began
Authors
Scot K. Izuka, Lyman L. Abbott