This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). These data document the PRMS output data files for the precalibration, byHRU, and byPOIobs release runs for the HI domain produced for the period 1980–2021. Each .zip folder contains 15 NHM-PRMS output variables, in NetCDF format, for each simulation's release run and the Water-Budget File with the model-domain summary table of the HI domain (Markstrom and others, 2015; Hay and others, 2023). The main landing page provides additional information and a data dictionary (output_variables_data_dictionary.csv) which describes the selected output variables. CONTENTS OF THIS CHILD PAGE: 1. HI_precalibration.zip = Folder containing outputs from the precalibration release run for the HI domain. 2. HI_byHRU.zip = Folder containing outputs from the byHRU release run for the HI domain. 3. HI_byPOIobs.zip = Folder containing outputs from the byPOIobs release run for the HI domain.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). Historical simulations using the Daymet Version 4 gridded estimates of daily weather parameters (Thornton and others, 2020) were produced for the period 1980–2021. These data document the PRMS climate input data files for these simulations. Input files for the simulations include the PRMS parameter file and control file. The main landing page provides additional information and data dictionaries (parameters_data_dictionary.csv and control_data_dictionary.csv) that describe the parameter and control file values. Daymet forcings include precipitation and minimum and maximum temperature at a daily time-step. Available USGS measured streamflow data are included for 196 USGS streamgage locations from 1980–2021 (U.S. Geological Survey, 2022). CONTENTS OF THIS CHILD PAGE: 1. Precip.day = daily total precipitation climate-by-hydrologic response unit (CBH) file 2. Tmax.day = maximum daily temperature CBH file 3. Tmin.day = minimum daily temperature CBH file. 4. sf_data = daily measured USGS streamflow data 5. PRMS Version 5.2.1.1 = PRMS executable 6. HI_precalibration.param = PRMS parameter file for the HI domain precalibration release 7. HI_precalibration.control = PRMS control file for the HI domain precalibration release 8. HI_byHRU.param = PRMS parameter file for the HI domain byHRU release 9. HI_byHRU.control = PRMS control file for the HI domain byHRU release 10. HI_byPOIobs.param = PRMS parameter file for the HI domain byPOIobs release 11. HI_byPOIobs.control = PRMS control file for the HI domain byPOIobs release 12. HI_NHM_PRMS.bat = batch file that can be edited to run the model.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). Historical simulations using the Daymet Version 4 gridded estimates of daily weather parameters (Thornton and others, 2020) were produced for the period 1980–2021. These data document the PRMS climate input data files for these simulations. Input files for the simulations include the PRMS parameter file and control file. The main landing page provides additional information and data dictionaries (parameters_data_dictionary.csv and control_data_dictionary.csv) that describe the parameter and control file values. Daymet forcings include precipitation and minimum and maximum temperature at a daily time-step. Available USGS measured streamflow data are included for 196 USGS streamgage locations from 1980–2021 (U.S. Geological Survey, 2022). CONTENTS OF THIS CHILD PAGE: 1. Precip.day = daily total precipitation climate-by-hydrologic response unit (CBH) file 2. Tmax.day = maximum daily temperature CBH file 3. Tmin.day = minimum daily temperature CBH file. 4. sf_data = daily measured USGS streamflow data 5. PRMS Version 5.2.1.1 = PRMS executable 6. HI_precalibration.param = PRMS parameter file for the HI domain precalibration release 7. HI_precalibration.control = PRMS control file for the HI domain precalibration release 8. HI_byHRU.param = PRMS parameter file for the HI domain byHRU release 9. HI_byHRU.control = PRMS control file for the HI domain byHRU release 10. HI_byPOIobs.param = PRMS parameter file for the HI domain byPOIobs release 11. HI_byPOIobs.control = PRMS control file for the HI domain byPOIobs release 12. HI_NHM_PRMS.bat = batch file that can be edited to run the model.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). Simulated streamflow stored in this child item (NHM-PRMS_data_release.nc) and statistics at streamgages (gage_stats_gm.csv) are provided for one pre-calibration and two calibration configurations (byHRU, and byPOIobs). The streamgage statistics file provides the Nash-Sutcliffe Efficiency Index between observed and simulated streamflow using daily, log of daily, monthly, and log of monthly values along with the bias, and drainage area for the model and streamgage for each Point-of-Interest (POI) in the simulation. The simulated streamflow file contains simulated and observed streamflow values for each POI in the simulation for 1980-2021. The main landing page provides additional information about the calibrations and a data dictionary (simulated_streamflow_data_dictionary.csv) which describes the simulated streamflow variables. CONTENTS OF THIS CHILD PAGE: 1. HI_stats_precalibration.zip = Folder containing simulated streamflow and statistics at streamgages from the precalibration release run for the HI domain. 2. HI_stats_byHRU.zip = Folder containing simulated streamflow and statistics at streamgages from the byHRU release run for the HI domain. 3. HI_stats_byPOIobs.zip = Folder containing simulated streamflow and statistics at streamgages from the byPOIobs release run for the HI domain.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). Simulated streamflow stored in this child item (NHM-PRMS_data_release.nc) and statistics at streamgages (gage_stats_gm.csv) are provided for one pre-calibration and two calibration configurations (byHRU, and byPOIobs). The streamgage statistics file provides the Nash-Sutcliffe Efficiency Index between observed and simulated streamflow using daily, log of daily, monthly, and log of monthly values along with the bias, and drainage area for the model and streamgage for each Point-of-Interest (POI) in the simulation. The simulated streamflow file contains simulated and observed streamflow values for each POI in the simulation for 1980-2021. The main landing page provides additional information about the calibrations and a data dictionary (simulated_streamflow_data_dictionary.csv) which describes the simulated streamflow variables. CONTENTS OF THIS CHILD PAGE: 1. HI_stats_precalibration.zip = Folder containing simulated streamflow and statistics at streamgages from the precalibration release run for the HI domain. 2. HI_stats_byHRU.zip = Folder containing simulated streamflow and statistics at streamgages from the byHRU release run for the HI domain. 3. HI_stats_byPOIobs.zip = Folder containing simulated streamflow and statistics at streamgages from the byPOIobs release run for the HI domain.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 for the precalibration, by Hydrologic Response Unit (byHRU) release, and by Point Of Interest Observation (byPOIobs) release using the USGS National Hydrologic Model infrastructure (NHM; Regan and others, 2018). These simulations were developed to provide estimates of the water budget for the calendar-year period 1980 to 2021, where the first two years are used for model initialization. Specific file types include: 1) input atmospheric forcings of minimum air temperature, maximum air temperature, and daily precipitation accumulation derived from Daymet Version 4 gridded estimates of daily weather parameters (Thornton and others, 2020) and input parameter and control files for each release (Markstrom and others, 2015), 2) monthly calibration target baselines derived from Global Circulation Model (GCM) simulations (Koczot and others, 2025) that were used in addition to USGS measured streamflow, 3) output files of simulated water budget components for each hydrologic response unit and stream segment and 4) performance statistics at selected streamgage locations. Figure 1 shows the calibration methodology that was used for the model application (see Hay and others, 2023 for additional information). Figure 2 shows all the HRUSs in the geospatial fabric for the HI domain (Bock and others, 2024). Table 1 lists the streamgages that are included in the model application. The first two years of the simulations are considered 'model initialization' and should not be included in any subsequent analysis. The executable used for these simulations may be downloaded from https://www.usgs.gov/software/precipitation-runoff-modeling-system-prms (version 5.2.1.1). A batch file to run the model has also been included.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 for the precalibration, by Hydrologic Response Unit (byHRU) release, and by Point Of Interest Observation (byPOIobs) release using the USGS National Hydrologic Model infrastructure (NHM; Regan and others, 2018). These simulations were developed to provide estimates of the water budget for the calendar-year period 1980 to 2021, where the first two years are used for model initialization. Specific file types include: 1) input atmospheric forcings of minimum air temperature, maximum air temperature, and daily precipitation accumulation derived from Daymet Version 4 gridded estimates of daily weather parameters (Thornton and others, 2020) and input parameter and control files for each release (Markstrom and others, 2015), 2) monthly calibration target baselines derived from Global Circulation Model (GCM) simulations (Koczot and others, 2025) that were used in addition to USGS measured streamflow, 3) output files of simulated water budget components for each hydrologic response unit and stream segment and 4) performance statistics at selected streamgage locations. Figure 1 shows the calibration methodology that was used for the model application (see Hay and others, 2023 for additional information). Figure 2 shows all the HRUSs in the geospatial fabric for the HI domain (Bock and others, 2024). Table 1 lists the streamgages that are included in the model application. The first two years of the simulations are considered 'model initialization' and should not be included in any subsequent analysis. The executable used for these simulations may be downloaded from https://www.usgs.gov/software/precipitation-runoff-modeling-system-prms (version 5.2.1.1). A batch file to run the model has also been included.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). This child item holds GIS layers and methodology to make mean-monthly calibration targets (baselines) for the HI domain, as was used in the "byHRU" calibration. Global Circulation Model (GCM) data from National Aeronautics and Space Administration (NASA) were processed into 10 mean-monthly global datasets (Koczot and others, 2025) and stored in NetCDF format ( .nc file extension; https://www.unidata.ucar.edu/software/netcdf/ ). Using these datasets, mean-monthly values were computed for each hydrologic response unit (HRU) in the HI domain (Bock and others, 2024). Resulting data are used as calibration targets for the HI NHM-PRMS model application. DATA TYPE DESIGNATION: Data layers are labeled according to type, as shown below: ID Data Type 1. AET Actual evapotranspiration 2. GW Groundwater (really baseflow) component of total runoff. 3. PET Potential evapotranspiration 4. SCA Snow-cover area (fraction of cell area) from NASA FLDAS. 5. SM Soil moisture 6. SR Solar radiation 7. SRO Surface runoff 8. SSR Subsurface runoff. 9. SWE Snow-water equivalent 10. SWI Soil-water infiltration CONTENTS OF THIS CHILD PAGE: 1. HI_HRU_baseline_targets.zip = Folder containing the 10 mean-monthly calibration target shapefiles files used in the by-HRU calibration step for each of the data types defined above.

This data release contains inputs for and outputs from hydrologic simulations for the Hawai‘i (HI) domain using the Precipitation Runoff Modeling System (PRMS) version 5.2.1.1 and the USGS National Hydrologic Model infrastructure (NHM, Regan and others, 2018). This child item holds GIS layers and methodology to make mean-monthly calibration targets (baselines) for the HI domain, as was used in the "byHRU" calibration. Global Circulation Model (GCM) data from National Aeronautics and Space Administration (NASA) were processed into 10 mean-monthly global datasets (Koczot and others, 2025) and stored in NetCDF format ( .nc file extension; https://www.unidata.ucar.edu/software/netcdf/ ). Using these datasets, mean-monthly values were computed for each hydrologic response unit (HRU) in the HI domain (Bock and others, 2024). Resulting data are used as calibration targets for the HI NHM-PRMS model application. DATA TYPE DESIGNATION: Data layers are labeled according to type, as shown below: ID Data Type 1. AET Actual evapotranspiration 2. GW Groundwater (really baseflow) component of total runoff. 3. PET Potential evapotranspiration 4. SCA Snow-cover area (fraction of cell area) from NASA FLDAS. 5. SM Soil moisture 6. SR Solar radiation 7. SRO Surface runoff 8. SSR Subsurface runoff. 9. SWE Snow-water equivalent 10. SWI Soil-water infiltration CONTENTS OF THIS CHILD PAGE: 1. HI_HRU_baseline_targets.zip = Folder containing the 10 mean-monthly calibration target shapefiles files used in the by-HRU calibration step for each of the data types defined above.

This data release is part of a cooperative study to assess streamflow availability under low-flow conditions for streams on the island of Hawai'i and West Maui from 2021 to 2022. This data release contains seven child items that consist of the following files: (1) a metadata xml file describing the data release files and data attributes, (2) an annotated NWIS-Mapper screen-captured image showing the seepage-run measurement sites, and (3) a comma-delimited ascii data file with the discrete discharge measurements. 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 during fair-weather, low-flow conditions, generally characterized by negligible direct runoff within the reach. The measurements can be used to characterize the net seepage of water into (water gain) or out of (water loss) the stream channel between measurement sites provided that the measurements were made during stable, nonchanging flow conditions (or, in some cases, were made simultaneously during transient flow conditions) and external surface inflows (for example, a tributary) or outflows (for example, a diversion) of water to the reach are quantified and accounted for in the computation of net seepage.