Hawai'i National Hydrologic Model (NHM) application,1980–2021

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.