The U.S. Geological Survey (USGS) developed a regression model for estimating mean August baseflow per square mile of drainage area in cooperation with National Oceanic and Atmospheric Administration (NOAA) to help resource managers assess relative amounts of baseflow in streams with Maine Atlantic Salmon habitat (Lombard and others, 2021). The model was applied to each reach of a stream network derived from select National Hydrography Dataset Plus High-Resolution (NHDPlusHR) data in the State of Maine south of 46º 21′55″ N latitude. The spatial coverage developed from the stream network contains model-estimated mean August baseflow per square mile of drainage area as an attribute of each NHDPlusHR reach. It is provided here as a shapefile (“Maine_Mean_August_Baseflow_Map.zip”) and published as a Web Map Service (WMS) layer that is hosted as a state map layer on the StreamStats web application for Maine (https://streamstats.usgs.gov/ss/). Please note that the regression equation from Lombard and others (2021) used to calculate model-estimated mean August baseflow values was adapted for English units for this application. The adapted equation is as follows: BFaug = -0.623 + 0.00988AQ + 0.241JULYAVEPRE Where BFaug is the mean August baseflow in cubic feet per second per square miles of drainage area; AQ is the fraction of the basin underlain by sand and gravel aquifers; and JULYAVEPRE is the basin-wide average of the mean July precipitation in inches. The model has an adjusted coefficient of determination (R²) of 0.78 and a mean 95% prediction interval of plus or minus 0.183 cubic feet per second per square mile.

The U.S. Geological Survey (USGS) in cooperation with NOAA, developed a regression model for estimating August mean baseflow per square mile of drainage area to help resource managers assess relative amounts of baseflow in streams with Maine Atlantic Salmon habitat. The model was derived from August mean baseflows computed at 31 USGS streamgages in and near the Gulf of Maine Atlantic Salmon Habitat Recovery Units. An ordinary least squares regression model estimates August mean baseflow per unit drainage area using two explanatory variables: percentage of the basin underlain by sand and gravel aquifers, and the basin mean July precipitation. This model provides the means to estimate August mean baseflow in cubic feet per second per square mile of basin area on user-selected ungaged sites throughout Maine south of 46º 21′55″ N latitude. Estimates will support prioritization of habitat conservation and restoration work for those reaches that offer baseflow refugia during summer low-flow periods, and thus have the potential to be high-quality Atlantic Salmon habitat. This data release includes 3 excel tables of data used in these analyses.

The U.S. Geological Survey (USGS) in cooperation with NOAA, developed a regression model for estimating August mean baseflow per square mile of drainage area to help resource managers assess relative amounts of baseflow in streams with Maine Atlantic Salmon habitat. The model was derived from August mean baseflows computed at 31 USGS streamgages in and near the Gulf of Maine Atlantic Salmon Habitat Recovery Units. An ordinary least squares regression model estimates August mean baseflow per unit drainage area using two explanatory variables: percentage of the basin underlain by sand and gravel aquifers, and the basin mean July precipitation. This model provides the means to estimate August mean baseflow in cubic feet per second per square mile of basin area on user-selected ungaged sites throughout Maine south of 46º 21′55″ N latitude. Estimates will support prioritization of habitat conservation and restoration work for those reaches that offer baseflow refugia during summer low-flow periods, and thus have the potential to be high-quality Atlantic Salmon habitat. This data release includes 3 excel tables of data used in these analyses.

This USGS data release contains products that resulted from aquatic species distribution modeling in the United States on the National Hydrography Dataset Plus Version 2.1. Source data, supporting code and model results are documented in this data release. The file species_model_list.csv provides a list of most recent models for each combination of species, habitat, and region.

This USGS data release contains products that resulted from aquatic species distribution modeling in the United States on the National Hydrography Dataset Plus Version 2.1. Source data, supporting code and model results are documented in this data release. The file species_model_list.csv provides a list of most recent models for each combination of species, habitat, and region.

This data release documents the data used for the associated publication "Evaluating hydrologic region assignment techniques for ungaged watersheds in Alaska, USA" (Barnhart and others, 2022) The data sets within this release are stored in 14 files: (1) Streamflow observations and sites used. (2) Statistically estimated streamflow values computed for each site. (3) Streamflow statistics computed from observed and estimated streamflow values at each site, basin characteristics for each site, and hydrologic regions (clusters) for each site. (4) A dataset describing the optimal number of hydrologic regions into which the considered sites were grouped. (5) P-values from a multiple comparisons analysis testing for statistical differences between clusters for each basin characteristic and streamflow statistic. (6) A matrix of zeros and ones describing the performance of each hydrologic region assignment technique considered in the publication associated with this release. (7) A dataset of variable importance generated by random forest modeling-based hydrologic region assignment techniques evaluated. (8-14) Daily datasets of simulated SnowModel (Liston and Elder, 2006) runoff (snowmelt + rainfall), precipitation, glacial melt, snow water equivalent, snow covered area, liquid precipitation, and air temperature for Alaska, USA at a 1 km grid cell size.

This data release documents the data used for the associated publication "Evaluating hydrologic region assignment techniques for ungaged watersheds in Alaska, USA" (Barnhart and others, 2022) The data sets within this release are stored in 14 files: (1) Streamflow observations and sites used. (2) Statistically estimated streamflow values computed for each site. (3) Streamflow statistics computed from observed and estimated streamflow values at each site, basin characteristics for each site, and hydrologic regions (clusters) for each site. (4) A dataset describing the optimal number of hydrologic regions into which the considered sites were grouped. (5) P-values from a multiple comparisons analysis testing for statistical differences between clusters for each basin characteristic and streamflow statistic. (6) A matrix of zeros and ones describing the performance of each hydrologic region assignment technique considered in the publication associated with this release. (7) A dataset of variable importance generated by random forest modeling-based hydrologic region assignment techniques evaluated. (8-14) Daily datasets of simulated SnowModel (Liston and Elder, 2006) runoff (snowmelt + rainfall), precipitation, glacial melt, snow water equivalent, snow covered area, liquid precipitation, and air temperature for Alaska, USA at a 1 km grid cell size.

The data release documents the development of a hybrid (statistical-mechanistic) SPARROW (SPAtially Referenced Regression On Watershed attributes) model of long-term mean annual streamflow applied to streams and rivers of conterminous United States. The model coupled previous catchment-scale (1-km) water balance predictions of “natural” unit-area runoff, which are inclusive of major water cycling processes, with additional explanatory variables (e.g., soils, vegetation, land use, topography, water losses in streams and reservoirs) that account for the effects of natural and cultural water supply and demand processes that operate over large spatial scales and explain streamflow variability across the conterminous United States river basins. The model performance was compared with that for six more simple models as described in the journal article. This USGS data release contains all of the input and output files for the execution of all of the models described in the journal article (see Table 1; https://doi.org/10.1029/2019WR025001). An R script is provided that allows users to execute the seven models.

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.

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.