Scot Izuka is a hydrologist with the Pacific Islands Water Science Center in Honolulu, Hawaiʻi.
Scot Izuka has been a hydrologist with the USGS Pacific Islands Water Science Center since 1989 and has conducted water-resources studies in Hawai‘i, American Samoa, and Micronesia. Most of his work is in island groundwater and surface-water hydrology, but he also has published research in geomorphology, climate, sedimentology, stratigraphy, geochemistry, geochronology, paleontology, and paleogeography. Scot is currently the project lead for the Hawai‘i Volcanic Aquifer Study, one of several regional groundwater-availability assessments being conducted by the USGS Water Availability and Use Science Program.
Education
PhD, Geology and Geophysics, University of Hawai‘i at Mānoa, 1988
MS, Geology, University of Kansas, 1983
BS, Geology and Geophysics, University of Hawai‘i at Mānoa, 1981
Professional Experience
Hydrologist, USGS Pacific Islands Water Science Center, Honolulu, Hawai‘i, 1989–present
Affiliate Graduate Faculty, Geology and Geophysics, University of Hawai‘i at Mānoa, 2017–present
Lecturer, Department of Math and Science, Kapi‘olani Community College, University of Hawai‘i, 1988–1991
Science and Products
Seepage-run discharge measurements, August 9, 2022, He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i
This data release contains a comma-delimited ascii file of 16 discrete discharge measurements made at sites along selected reaches of He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i, on August 9, 2022. These discrete discharge measurements form what is commonly referred to as a "seepage run." The intent of the seepage run is to quantify the spatial distribution of streamflow along the reach dur
Seepage-run discharge measurements, November 15, 2021, He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i
This data release contains a comma-delimited ascii file of 16 discrete discharge measurements made at sites along selected reaches of He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i, on November 15, 2021. These discrete discharge measurements form what is commonly referred to as a "seepage run." The intent of the seepage run is to quantify the spatial distribution of streamflow along the reach
Seepage-run discharge measurements, September 8, 2021, He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i
This data release contains a comma-delimited ascii file of nine discrete discharge measurements made at sites along selected reaches of He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i, on September 8, 2021. These discrete discharge measurements form what is commonly referred to as a "seepage run." The intent of the seepage run is to quantify the spatial distribution of streamflow alon
MODFLOW-2005 and SWI2 models for assessing groundwater availability in the volcanic aquifers of Kauai, Oahu, and Maui, Hawaii
Steady-state numerical groundwater-flow models were constructed for the
islands of Kaua'i, O'ahu, and Maui, Hawai'i. Separate models were created
for each island using MODFLOW-2005 (Harbaugh, 2005) with the Seawater
Intrusion (SWI2) package (Bakker and others, 2013), which allows simulation
of freshwater and saltwater in ocean-island aquifers. The purpose of the models
is to enable quantifica
Filter Total Items: 25
The Hawai'i groundwater recharge tool
This article discusses the design and implementation of the Hawai’i Groundwater
Recharge Tool, an application for providing data and analyses of the impacts
of land-cover modifications and changes in precipitation on groundwater-recharge
rates for the island of O’ahu. This application uses simulation data based on a set of
29 land-cover types and 2 precipitation conditions to provide users with re
Volcanic Aquifers of Hawai‘i—Construction and calibration of numerical models for assessing groundwater availability on Kaua‘i, O‘ahu, and Maui
Steady-state numerical groundwater-flow models were constructed for the islands of Kaua‘i, O‘ahu, and Maui to enable quantification of the hydrologic consequences of withdrawals and other stresses that can place limits on groundwater availability. The volcanic aquifers of Hawai‘i supply nearly all drinking water for the islands’ residents, freshwater for diverse industries, and natural discharge t
Water-resource management monitoring needs, State of Hawai‘i
In cooperation with the State of Hawai‘i Commission on Water Resource Management and in collaboration with the University of Hawaiʻi Water Resources Research Center, the U.S. Geological Survey developed a water-resource monitoring program—a rainfall, surface-water, and groundwater data-collection program—that is required to meet State needs for water-resource assessment, management, and protection
The ‘Ike Wai Hawai‘i groundwater recharge tool
This paper discusses the design and implementation
of the ‘Ike Wai Hawai‘i Groundwater Recharge Tool, an
application for providing data and analyses of the impacts of
land-cover and climate modifications on groundwater-recharge
rates for the island of O‘ahu. This application uses simulation
data based on a set of 29 land-cover types and two rainfall
scenarios to provide users with real-time rechar
Enabling real-time user interaction for decision support: Experiences extending a local agave platform metadata service
The University of Hawai'i Information Technology Services Cyber-infrastructure team in partnership with the United States Geological Survey developed the Hawai'i groundwater recharge tool, a decision support tool, as part of the 'Ike Wai Gateway to support water sustainability research for the state of Hawai'i. To enable the development of the tool within the existing University of Hawai'i Agave p
Hawai‘i Groundwater Recharge Tool
The Hawai‘i Groundwater Recharge Tool allows users to evaluate the potential effects of land-cover and climate changes on groundwater recharge. This website provides a baseline estimate of recharge representing recent conditions of precipitation (1978–2008 average) and land cover (2010). Users can change land cover and rainfall conditions to evaluate the effects on groundwater recharge. Results wi
Volcanic aquifers of Hawai‘i—Hydrogeology, water budgets, and conceptual models
Hawai‘i’s aquifers have limited capacity to store fresh groundwater because each island is small and surrounded by saltwater. Saltwater also underlies much of the fresh groundwater. Fresh groundwater resources are, therefore, particularly vulnerable to human activity, short-term climate cycles, and long-term climate change. Availability of fresh groundwater for human use is constrained by the degr
Onset of rejuvenated-stage volcanism and the formation of Līhu‘e Basin: Kaua‘i events that occurred 3-4 million years ago
For ocean-island volcanoes, an understanding of rejuvenated-stage volcanism requires knowing the age of onset, duration of the volcanic episode, and length of quiescence that preceded the rejuvenated pulse. On the Island of Kaua‘i, cuttings from two lava flows intercepted in the Hanamā‘ulu well (Līhu‘e basin) and assigned to the Kōloa Volcanics on basis of major-element, trace-element, and isotope
Spatially distributed groundwater recharge for 2010 land cover estimated using a water-budget model for the Island of O‘ahu, Hawai‘i
Owing mainly to projected population growth, demand for freshwater on the Island of Oʻahu is expected to increase by about 26 percent between 2010 and 2030, according to the City and County of Honolulu. Estimates of groundwater recharge are needed to evaluate the availability of fresh groundwater. For this study, a water-budget model with a daily computation interval was developed and used to esti
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
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
Science and Products
- Science
- Data
Seepage-run discharge measurements, August 9, 2022, He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i
This data release contains a comma-delimited ascii file of 16 discrete discharge measurements made at sites along selected reaches of He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i, on August 9, 2022. These discrete discharge measurements form what is commonly referred to as a "seepage run." The intent of the seepage run is to quantify the spatial distribution of streamflow along the reach durSeepage-run discharge measurements, November 15, 2021, He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i
This data release contains a comma-delimited ascii file of 16 discrete discharge measurements made at sites along selected reaches of He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i, on November 15, 2021. These discrete discharge measurements form what is commonly referred to as a "seepage run." The intent of the seepage run is to quantify the spatial distribution of streamflow along the reachSeepage-run discharge measurements, September 8, 2021, He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i
This data release contains a comma-delimited ascii file of nine discrete discharge measurements made at sites along selected reaches of He'eia Stream and 'Ioleka'a Stream, O'ahu, Hawai'i, on September 8, 2021. These discrete discharge measurements form what is commonly referred to as a "seepage run." The intent of the seepage run is to quantify the spatial distribution of streamflow alonMODFLOW-2005 and SWI2 models for assessing groundwater availability in the volcanic aquifers of Kauai, Oahu, and Maui, Hawaii
Steady-state numerical groundwater-flow models were constructed for the islands of Kaua'i, O'ahu, and Maui, Hawai'i. Separate models were created for each island using MODFLOW-2005 (Harbaugh, 2005) with the Seawater Intrusion (SWI2) package (Bakker and others, 2013), which allows simulation of freshwater and saltwater in ocean-island aquifers. The purpose of the models is to enable quantifica - Multimedia
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Filter Total Items: 25
The Hawai'i groundwater recharge tool
This article discusses the design and implementation of the Hawai’i Groundwater Recharge Tool, an application for providing data and analyses of the impacts of land-cover modifications and changes in precipitation on groundwater-recharge rates for the island of O’ahu. This application uses simulation data based on a set of 29 land-cover types and 2 precipitation conditions to provide users with reVolcanic Aquifers of Hawai‘i—Construction and calibration of numerical models for assessing groundwater availability on Kaua‘i, O‘ahu, and Maui
Steady-state numerical groundwater-flow models were constructed for the islands of Kaua‘i, O‘ahu, and Maui to enable quantification of the hydrologic consequences of withdrawals and other stresses that can place limits on groundwater availability. The volcanic aquifers of Hawai‘i supply nearly all drinking water for the islands’ residents, freshwater for diverse industries, and natural discharge tWater-resource management monitoring needs, State of Hawai‘i
In cooperation with the State of Hawai‘i Commission on Water Resource Management and in collaboration with the University of Hawaiʻi Water Resources Research Center, the U.S. Geological Survey developed a water-resource monitoring program—a rainfall, surface-water, and groundwater data-collection program—that is required to meet State needs for water-resource assessment, management, and protectionThe ‘Ike Wai Hawai‘i groundwater recharge tool
This paper discusses the design and implementation of the ‘Ike Wai Hawai‘i Groundwater Recharge Tool, an application for providing data and analyses of the impacts of land-cover and climate modifications on groundwater-recharge rates for the island of O‘ahu. This application uses simulation data based on a set of 29 land-cover types and two rainfall scenarios to provide users with real-time recharEnabling real-time user interaction for decision support: Experiences extending a local agave platform metadata service
The University of Hawai'i Information Technology Services Cyber-infrastructure team in partnership with the United States Geological Survey developed the Hawai'i groundwater recharge tool, a decision support tool, as part of the 'Ike Wai Gateway to support water sustainability research for the state of Hawai'i. To enable the development of the tool within the existing University of Hawai'i Agave pHawai‘i Groundwater Recharge Tool
The Hawai‘i Groundwater Recharge Tool allows users to evaluate the potential effects of land-cover and climate changes on groundwater recharge. This website provides a baseline estimate of recharge representing recent conditions of precipitation (1978–2008 average) and land cover (2010). Users can change land cover and rainfall conditions to evaluate the effects on groundwater recharge. Results wiVolcanic aquifers of Hawai‘i—Hydrogeology, water budgets, and conceptual models
Hawai‘i’s aquifers have limited capacity to store fresh groundwater because each island is small and surrounded by saltwater. Saltwater also underlies much of the fresh groundwater. Fresh groundwater resources are, therefore, particularly vulnerable to human activity, short-term climate cycles, and long-term climate change. Availability of fresh groundwater for human use is constrained by the degrOnset of rejuvenated-stage volcanism and the formation of Līhu‘e Basin: Kaua‘i events that occurred 3-4 million years ago
For ocean-island volcanoes, an understanding of rejuvenated-stage volcanism requires knowing the age of onset, duration of the volcanic episode, and length of quiescence that preceded the rejuvenated pulse. On the Island of Kaua‘i, cuttings from two lava flows intercepted in the Hanamā‘ulu well (Līhu‘e basin) and assigned to the Kōloa Volcanics on basis of major-element, trace-element, and isotopeSpatially distributed groundwater recharge for 2010 land cover estimated using a water-budget model for the Island of O‘ahu, Hawai‘i
Owing mainly to projected population growth, demand for freshwater on the Island of Oʻahu is expected to increase by about 26 percent between 2010 and 2030, according to the City and County of Honolulu. Estimates of groundwater recharge are needed to evaluate the availability of fresh groundwater. For this study, a water-budget model with a daily computation interval was developed and used to estiSources 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 fPotential 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