Scot K Izuka
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
MODFLOW-2005 and SWI2 models for assessing groundwater availability scenarios in volcanic aquifers on Kauai, Oahu, and Maui, Hawaii
Previously constructed steady-state numerical groundwater-flow models for the islands of Kauai, Oahu, and Maui, Hawaii (https://doi.org/10.3133/sir20205126) using MODFLOW-2005 with the Seawater Intrusion (SWI2) package, were used to examine the consequences of historical and plausible future withdrawals and changes in recharge. The volcanic aquifers of the Hawaiian Islands supply water to 1.46 mil
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 along the reac
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: 28
Groundwater and surface-water interactions in the He‘eia watershed, O‘ahu, Hawai‘i—Insights from analysis of historical data and numerical groundwater-model simulations
He‘eia and ‘Ioleka‘a Streams in the He‘eia watershed on O‘ahu, Hawai‘i, receive substantial discharge from dike-impounded groundwater. Previous studies indicated that groundwater withdrawals from the watershed affect streamflow. Resource managers and users seek information that can be used to balance the needs of competing uses of groundwater and streamflow in the watershed.In this study, analyses
Authors
Scot K. Izuka, Heidi L. Kāne, Kolja Rotzoll
Availability of groundwater from the volcanic aquifers of the Hawaiian Islands
The islands of Hawaiʻi were built by basaltic shield volcanoes in the Pacific Ocean. These volcanoes formed aquifers that supply hundreds of millions of gallons of fresh water per day to the islands’ residents and diverse industries. Groundwater discharge from the volcanic aquifers to streams and the coast also supports traditional practices and ecosystems. The aquifers' capacity to yield fresh gr
Authors
Scot K. Izuka, Kolja Rotzoll
Volcanic aquifers of Hawaiʻi—Contributions to assessing groundwater availability on Kauaʻi, Oʻahu, and Maui
The volcanic aquifers of the Hawaiian Islands supply water to 1.46 million residents, diverse industries, and a large component of the U.S. military in the Pacific. Groundwater also supplies fresh water that supports ecosystems in streams and near the coast. Hawaii’s aquifers are remarkably productive given their small size, but the capacity of the islands to store fresh groundwater is limited bec
Authors
Scot K. Izuka, Kolja Rotzoll
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
Authors
Jared H. McLean, Sean B. Cleveland, Kolja Rotzoll, Scot K. Izuka, Jason Leigh, Gwen A. Jacobs, Ryan Theriot
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
Authors
Scot K. Izuka, Kolja Rotzoll, Tracy Nishikawa
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
Authors
Chui Ling Cheng, Scot K. Izuka, Joseph Kennedy, Abby G. Frazier, Thomas W. Giambelluca
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
Authors
Jared H. McLean, Sean B. Cleaveland, Kolja Rotzoll, Scot K. Izuka, Jason Leigh, Gwen A. Jacobs, Ryan Theriot
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
Authors
Sean B. Cleveland, Jared H. McClean, Kolja Rotzoll, Scot K. Izuka, Gwen A. Jacobs
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
Authors
Jared H. McLean, Kolja Rotzoll, Sean B. Cleaveland, Scot K. Izuka
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
Authors
Scot K. Izuka, John A. Engott, Kolja Rotzoll, Maoya Bassiouni, Adam G. Johnson, Lisa D. Miller, Alan Mair
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
Authors
John A. Engott, Adam G. Johnson, Maoya Bassiouni, Scot K. Izuka, Kolja Rotzoll
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
Authors
David R. Sherrod, Scot K. Izuka, Brian L. Cousens
Science and Products
MODFLOW-2005 and SWI2 models for assessing groundwater availability scenarios in volcanic aquifers on Kauai, Oahu, and Maui, Hawaii
Previously constructed steady-state numerical groundwater-flow models for the islands of Kauai, Oahu, and Maui, Hawaii (https://doi.org/10.3133/sir20205126) using MODFLOW-2005 with the Seawater Intrusion (SWI2) package, were used to examine the consequences of historical and plausible future withdrawals and changes in recharge. The volcanic aquifers of the Hawaiian Islands supply water to 1.46 mil
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 along the reac
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: 28
Groundwater and surface-water interactions in the He‘eia watershed, O‘ahu, Hawai‘i—Insights from analysis of historical data and numerical groundwater-model simulations
He‘eia and ‘Ioleka‘a Streams in the He‘eia watershed on O‘ahu, Hawai‘i, receive substantial discharge from dike-impounded groundwater. Previous studies indicated that groundwater withdrawals from the watershed affect streamflow. Resource managers and users seek information that can be used to balance the needs of competing uses of groundwater and streamflow in the watershed.In this study, analyses
Authors
Scot K. Izuka, Heidi L. Kāne, Kolja Rotzoll
Availability of groundwater from the volcanic aquifers of the Hawaiian Islands
The islands of Hawaiʻi were built by basaltic shield volcanoes in the Pacific Ocean. These volcanoes formed aquifers that supply hundreds of millions of gallons of fresh water per day to the islands’ residents and diverse industries. Groundwater discharge from the volcanic aquifers to streams and the coast also supports traditional practices and ecosystems. The aquifers' capacity to yield fresh gr
Authors
Scot K. Izuka, Kolja Rotzoll
Volcanic aquifers of Hawaiʻi—Contributions to assessing groundwater availability on Kauaʻi, Oʻahu, and Maui
The volcanic aquifers of the Hawaiian Islands supply water to 1.46 million residents, diverse industries, and a large component of the U.S. military in the Pacific. Groundwater also supplies fresh water that supports ecosystems in streams and near the coast. Hawaii’s aquifers are remarkably productive given their small size, but the capacity of the islands to store fresh groundwater is limited bec
Authors
Scot K. Izuka, Kolja Rotzoll
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
Authors
Jared H. McLean, Sean B. Cleveland, Kolja Rotzoll, Scot K. Izuka, Jason Leigh, Gwen A. Jacobs, Ryan Theriot
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
Authors
Scot K. Izuka, Kolja Rotzoll, Tracy Nishikawa
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
Authors
Chui Ling Cheng, Scot K. Izuka, Joseph Kennedy, Abby G. Frazier, Thomas W. Giambelluca
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
Authors
Jared H. McLean, Sean B. Cleaveland, Kolja Rotzoll, Scot K. Izuka, Jason Leigh, Gwen A. Jacobs, Ryan Theriot
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
Authors
Sean B. Cleveland, Jared H. McClean, Kolja Rotzoll, Scot K. Izuka, Gwen A. Jacobs
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
Authors
Jared H. McLean, Kolja Rotzoll, Sean B. Cleaveland, Scot K. Izuka
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
Authors
Scot K. Izuka, John A. Engott, Kolja Rotzoll, Maoya Bassiouni, Adam G. Johnson, Lisa D. Miller, Alan Mair
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
Authors
John A. Engott, Adam G. Johnson, Maoya Bassiouni, Scot K. Izuka, Kolja Rotzoll
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
Authors
David R. Sherrod, Scot K. Izuka, Brian L. Cousens