This data release includes tabular surveyed and interpolated elevation data, the processed computational mesh, and model output data used in scour evaluations. The methods of deriving these datasets and using them to calculate scour are described in the associated Scientific Investigations Report "Scour evaluations and conditions at selected bridge sites in Alaska, 2016-2017”. This is a cooperative project with Alaska Department of Transportation and Public Facilities.

This dataset includes the input (raw survey data, computational mesh, hydrologic boundary conditions) and output data for a 2-dimensional hydraulic and sediment transport model of the lower Snow River flood plain near Seward, Alaska. Four outburst flood scenarios were simulated, including 3 historical floods and one hypothetical larger flood. The methods of deriving these datasets and using them to calculate scour are described in the associated USGS Scientific Investigations Report "Recent history of glacial outburst floods, analysis of channel changes, and development of a 2-dimensional flow and sediment transport model of the Snow River near Seward, Alaska".

This dataset includes the input (raw survey data, computational mesh, hydrologic boundary conditions) and output data for a 2-dimensional hydraulic and sediment transport model of the lower Snow River flood plain near Seward, Alaska. Four outburst flood scenarios were simulated, including 3 historical floods and one hypothetical larger flood. The methods of deriving these datasets and using them to calculate scour are described in the associated USGS Scientific Investigations Report "Recent history of glacial outburst floods, analysis of channel changes, and development of a 2-dimensional flow and sediment transport model of the Snow River near Seward, Alaska".

This data release contains inputs for and outputs from hydrologic simulations for the Alaska/Yukon (AK) 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 (NHM-PRMS_data_release.nc) and statistics at streamgages (gage_stats_gm.csv) are provided for one precalibration and one calibration configurations(byHRU). 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. AK_precal_NHM_PRMS_data_release.nc = AK precalibration, NetCDF file, simulated streamflows at gages. 2. AK_byHRU_NHM_PRMS_data_release.nc = AK byHRU, NetCDF file, simulated streamflows at gages. 3. Gage_stats_dm_ak_precal.csv = AK precalibration statistics at streamgages. 4. Gage_stats_dm_ak_byHRU.csv = AK byHRU statistics at streamgages.

This data release contains inputs for and outputs from hydrologic simulations for the Alaska/Yukon (AK) 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 (NHM-PRMS_data_release.nc) and statistics at streamgages (gage_stats_gm.csv) are provided for one precalibration and one calibration configurations(byHRU). 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. AK_precal_NHM_PRMS_data_release.nc = AK precalibration, NetCDF file, simulated streamflows at gages. 2. AK_byHRU_NHM_PRMS_data_release.nc = AK byHRU, NetCDF file, simulated streamflows at gages. 3. Gage_stats_dm_ak_precal.csv = AK precalibration statistics at streamgages. 4. Gage_stats_dm_ak_byHRU.csv = AK byHRU statistics at streamgages.

Since 1993 the U.S. Geological Survey (USGS) has worked with the Alaska Department of Transportation and Public Facilities (ADOT&PF) to provide hydraulic assessments of scour for bridges throughout Alaska. As part of this effort, repeat channel cross section surveys, or channel soundings, have been collected at either the upstream or downstream side of bridges on an annual or as needed basis. Streambed and bank elevations are measured using USGS sounding weights and reels, weighted measuring tapes, acoustic Doppler current profilers, multibeam echo sounders and light detection and ranging and are referenced to the datum of as-built plan set to provide context for the streambed elevations in relation to bridge structures. Channel soundings are collected on an annual basis at most sites, however, as need soundings are collected due to flooding or periods of scour at select sites. Repeat channel soundings are used to access stream stability related to seasons, stage, and long-term aggradation or degradation as well as providing greater context for fixed mount streambed elevation monitoring. New measurements are appended to this data release after they have undergone formal QA/QC processing. Please note the updated date in the suggested citation.

MODFLOW6 and SNTEMP models were developed to simulate groundwater flows and instream temperatures in Beaver Creek, Alaska from 2019-2023 using python scripts to create a reproducible workflow to process input datasets into model files. This data release contains the scripts used to build the SNTEMP and MODFLOW models, process model output to compare to field observations, and develop and run the PEST++ workflow for history matching. These workflows are described in the readme.md files in this archive and are used to implement the modeling decisions described in the associated report, "Simulating present and future Groundwater/Surface-water interactions and stream temperatures in Beaver Creek, Kenai Peninsula, Alaska".

MODFLOW6 and SNTEMP models were developed to simulate groundwater flows and instream temperatures in Beaver Creek, Alaska from 2019-2023 using python scripts to create a reproducible workflow to process input datasets into model files. This data release contains the scripts used to build the SNTEMP and MODFLOW models, process model output to compare to field observations, and develop and run the PEST++ workflow for history matching. These workflows are described in the readme.md files in this archive and are used to implement the modeling decisions described in the associated report, "Simulating present and future Groundwater/Surface-water interactions and stream temperatures in Beaver Creek, Kenai Peninsula, Alaska".

This dataset contains selected information about U.S. Geological Survey (USGS) streamgages in Alaska that had at least 5 years of daily streamflow record through September 30, 2017. The goals for developing this dataset were to identify USGS streamgages that had at least 5 years of daily streamflow that responded mostly to seasonal meteorological inputs, that had a definable drainage basin above a minimum size from which basin characteristics could be determined, and that provided streamflow data not similar to another streamgage record in the dataset. Streamgages meeting these criteria for at least part of their records constituted the dataset for a study investigating seasonal flow regimes and streamflow drivers for Alaska. For 253 streamgages meeting selection criteria, data include period of record characteristics, basin characteristics, and flow regime cluster analysis results. The basin characteristics are provided in their original U.S. customary units and as values transformed to metric units. For an additional 78 streamgages, data include the special conditions affecting streamflow that disqualified the streamgage from the study, including recurring outburst floods, regulation, urbanization, hydrologic redundancy with another streamgage, drainage basin below minimum size, or an indeterminate drainage basin.

To provide daily mean streamflow values at ungaged (partial-record) sites within the Yankee Fork Salmon River watershed, the U.S. Geological Survey (USGS), in cooperation with U.S. Bureau of Reclamation, used discharge measurements at three partial-record sites and related those measurements to a nearby USGS real-time streamgage (index site). Daily mean streamflow was estimated by developing a regression relationship between each partial-record site and the index site for water years 2012-2019. These data are intended to provide daily mean streamflow estimates at partial-record sites as part of a larger study (Clark and others, 2021) to estimate sediment loading for each site.