A three-dimensional, groundwater model (SUTRA) was developed to understand the effects of seawater washover on the freshwater lens of Roi-Namur, Kwajalein Atoll, Republic of the Marshall Islands. The model was calibrated by using observation data collected from 1990 through 1991 and 2008 through 2010. This USGS data release contains all of the input and output files for the simulations described in the associated journal article "Seawater-flooding events and impact on freshwater lenses of low-lying islands: controlling factors, basic management and mitigation" by Stephen B. Gingerich, Clifford I. Voss, and Adam G. Johnson, Journal of Hydrology (https://doi.org/10.1016/j.jhydrol.2017.03.001). This data release also includes (1) postprocessing python scripts, and (2) SUTRA source code.

A generalized two-dimensional flow model using an enhanced version of the SUTRA model (in press) was developed to examine active-layer dynamics and permafrost thaw development broadly applicable to boreal headwater catchments. Coupled fluid-flow and energy transport was simulated through various hillslope conditions basally bounded by permafrost and subjected to seasonal air-temperature variation with superimposed linear warming. The model domain represents a generalized 2-dimensional 100 m-long fully-saturated cross-sectional hillside that slopes downward to the left from the hill top (at elevation 5 m) to a small stream (at elevation 0 m). The data included here represent a model archive for a set of generalized simulations, including a basecase and 10 variations upon the basecase. Model output includes information on seasonal changes in subsurface temperature, ice/liquid saturation conditions, and baseflow over the simulated model time duration of 100 years total. This USGS data release contains all of the input and output files for the simulations described in the associated journal article (https://doi.org/10.1088/1748-9326/aaf0cc).

A generalized two-dimensional flow model using an enhanced version of the SUTRA model (in press) was developed to examine active-layer dynamics and permafrost thaw development broadly applicable to boreal headwater catchments. Coupled fluid-flow and energy transport was simulated through various hillslope conditions basally bounded by permafrost and subjected to seasonal air-temperature variation with superimposed linear warming. The model domain represents a generalized 2-dimensional 100 m-long fully-saturated cross-sectional hillside that slopes downward to the left from the hill top (at elevation 5 m) to a small stream (at elevation 0 m). The data included here represent a model archive for a set of generalized simulations, including a basecase and 10 variations upon the basecase. Model output includes information on seasonal changes in subsurface temperature, ice/liquid saturation conditions, and baseflow over the simulated model time duration of 100 years total. This USGS data release contains all of the input and output files for the simulations described in the associated journal article (https://doi.org/10.1088/1748-9326/aaf0cc).

Groundwater levels have declined since the 1940s in the Wailuku area of central Maui, Hawaiʻi, on the eastern flank of West Maui volcano, mainly in response to increased groundwater withdrawals. Available data since the 1980s also indicate a thinning of the freshwater lens and an increase in chloride concentrations of pumped water from production wells. These trends, combined with projected increases in demand for groundwater in central Maui, have led to concerns over groundwater availability and have highlighted a need to improve understanding of the hydrologic effects of proposed groundwater withdrawals in the Waiheʻe, ʻĪao, and Waikapū areas of central Maui. A three-dimensional, variable-density solute-transport model (SUTRA) was developed to evaluate the effects of seven selected withdrawal/recharge scenarios on water levels and salinity of groundwater in central Maui, Hawaiʻi. The model was constructed using water-level and salinity data available for the period from 1926 to 2012. Groundwater recharge for the model was estimated using a daily water budget for the period of interest. Inflow of groundwater at the model boundaries was estimated from an existing island-wide numerical groundwater-flow model (Izuka and others, 2021, available at https://doi.org/10.3133/sir20205126). The data release also includes the SUTRA source code and executable file used to run the simulations. The SUTRA code was modified to include a simplified representation of water-table storage (Gingerich, 2008, available at https://pubs.usgs.gov/sir/2008/5236/; Gingerich and Engott, 2012, available at https://pubs.usgs.gov/sir/2012/5010/). This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20215113).

Groundwater levels have declined since the 1940s in the Wailuku area of central Maui, Hawaiʻi, on the eastern flank of West Maui volcano, mainly in response to increased groundwater withdrawals. Available data since the 1980s also indicate a thinning of the freshwater lens and an increase in chloride concentrations of pumped water from production wells. These trends, combined with projected increases in demand for groundwater in central Maui, have led to concerns over groundwater availability and have highlighted a need to improve understanding of the hydrologic effects of proposed groundwater withdrawals in the Waiheʻe, ʻĪao, and Waikapū areas of central Maui. A three-dimensional, variable-density solute-transport model (SUTRA) was developed to evaluate the effects of seven selected withdrawal/recharge scenarios on water levels and salinity of groundwater in central Maui, Hawaiʻi. The model was constructed using water-level and salinity data available for the period from 1926 to 2012. Groundwater recharge for the model was estimated using a daily water budget for the period of interest. Inflow of groundwater at the model boundaries was estimated from an existing island-wide numerical groundwater-flow model (Izuka and others, 2021, available at https://doi.org/10.3133/sir20205126). The data release also includes the SUTRA source code and executable file used to run the simulations. The SUTRA code was modified to include a simplified representation of water-table storage (Gingerich, 2008, available at https://pubs.usgs.gov/sir/2008/5236/; Gingerich and Engott, 2012, available at https://pubs.usgs.gov/sir/2012/5010/). This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20215113).

This data release contains the input files for the watershed and water-balance models that simulate historic (1990‒2009) and future (2080‒2099) climate conditions on Guam. These simulations are described in the associated Scientific Investigations Report, “Water Resources on Guam—Potential Impacts of and Adaptive Response to Climate Change" by Stephen B. Gingerich, Adam G. Johnson, Sarah N. Rosa, Mathieu D. Marineau, Scott A. Wright, Lauren E. Hay, Matthew J. Widlansky, John W. Jenson, Corinne I. Wong, Jay L. Banner, Victoria W. Keener, and Melissa L. Finucane (https://doi.org/10.3133/sir20195095). The watershed and water-balance models were previously published in “Supporting data for Fena Valley Reservoir watershed and water-balance model, southern Guam” (Rosa and Hay, 2017). Data are provided in two folders: 1) the PRMS_2016_historic_future folder contains the climate by hydrologic response unit (HRU) data files (CBH_files folder) needed to drive each of the modeled regions in southern Guam for the historic and future periods and a README_PRMS_2016_historic_future.txt document that describes the contents of this folder and how to update the previously published model files (Rosa and Hay, 2017) and run the watershed model with the historic and future datasets; and 2) the FVR_2016_historic_future folder contains the input files needed to run the Fena Valley Reservoir water-balance model for the historic and future periods and a README_FVR_2016_historic_future.txt document that describes the contents of this folder and how to execute the water-balance model (Rosa and Hay, 2017) with the historic and future input files.

This data release contains the input files for the watershed and water-balance models that simulate historic (1990‒2009) and future (2080‒2099) climate conditions on Guam. These simulations are described in the associated Scientific Investigations Report, “Water Resources on Guam—Potential Impacts of and Adaptive Response to Climate Change" by Stephen B. Gingerich, Adam G. Johnson, Sarah N. Rosa, Mathieu D. Marineau, Scott A. Wright, Lauren E. Hay, Matthew J. Widlansky, John W. Jenson, Corinne I. Wong, Jay L. Banner, Victoria W. Keener, and Melissa L. Finucane (https://doi.org/10.3133/sir20195095). The watershed and water-balance models were previously published in “Supporting data for Fena Valley Reservoir watershed and water-balance model, southern Guam” (Rosa and Hay, 2017). Data are provided in two folders: 1) the PRMS_2016_historic_future folder contains the climate by hydrologic response unit (HRU) data files (CBH_files folder) needed to drive each of the modeled regions in southern Guam for the historic and future periods and a README_PRMS_2016_historic_future.txt document that describes the contents of this folder and how to update the previously published model files (Rosa and Hay, 2017) and run the watershed model with the historic and future datasets; and 2) the FVR_2016_historic_future folder contains the input files needed to run the Fena Valley Reservoir water-balance model for the historic and future periods and a README_FVR_2016_historic_future.txt document that describes the contents of this folder and how to execute the water-balance model (Rosa and Hay, 2017) with the historic and future input files.

A three-dimensional, variable-density solute-transport model (SUTRA) was developed to evaluate the effects of nine selected withdrawal/recharge scenarios on salinity of groundwater and discharge of freshwater to the nearshore environment of central Molokaʻi, Hawaiʻi. The model was constructed using water-level and salinity data available for the period from 1940 to 2012. Groundwater recharge for the model was estimated using a daily water budget for the period of interest. Inflow of groundwater at the model boundaries was estimated from an islandwide model based on a sharp-interface approach (SHARP). The island-wide model is included as part of this data release. The data release also includes the SUTRA and SHARP source codes and executable files used to run the simulations. The SHARP code was modified for input/output related to computing the boundary flows and the SUTRA code was modified to include simplified unsaturated zone properties in the subroutine UNSAT. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20195150).

A three-dimensional, variable-density solute-transport model (SUTRA) was developed to evaluate the effects of nine selected withdrawal/recharge scenarios on salinity of groundwater and discharge of freshwater to the nearshore environment of central Molokaʻi, Hawaiʻi. The model was constructed using water-level and salinity data available for the period from 1940 to 2012. Groundwater recharge for the model was estimated using a daily water budget for the period of interest. Inflow of groundwater at the model boundaries was estimated from an islandwide model based on a sharp-interface approach (SHARP). The island-wide model is included as part of this data release. The data release also includes the SUTRA and SHARP source codes and executable files used to run the simulations. The SHARP code was modified for input/output related to computing the boundary flows and the SUTRA code was modified to include simplified unsaturated zone properties in the subroutine UNSAT. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20195150).

A three-dimensional, variable-density solute-transport model (SUTRA) was developed to evaluate the effects of three selected withdrawal/injection scenarios on salinity of groundwater (as simulated at damselfly anchialine-pool habitat) and discharge of freshwater to the nearshore environment of Kaloko-Honokōhau National Historical Park (KAHO), Hawaiʻi. A base model was constructed using water-level, salinity, and withdrawal data available during the period from 2009 to 2017. Groundwater recharge for the base model was from a published daily water budget representing rainfall for the period 1984-2008. The SUTRA code was modified to include simplified unsaturated zone properties in the subroutine UNSAT. Changes in salinity of groundwater and discharge of freshwater relative to the base model were quantified for two withdrawal and one injection scenario. Each of the withdrawal/injection scenarios consists of 15 model runs, representing 15 independently tested withdrawal/injection sites. Model parameter values for the three-dimensional model were initially estimated using a two-dimensional cross section model and the model code SUTRA-MS, which allows simulation of both salinity and heat transport. The two-dimensional cross-section model was used to evaluate model sensitivity to selected features or flow-system conceptualizations. The four sensitivity-analysis model simulations were: (1) no heat transport; (2) confining units for the deep, coastal confined-groundwater system with dip of 5 degrees instead of 1 degree in the base model; (3) thick upper confining unit; and (4) no confining units. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20215004).