This tabular data set represents the percent of surficial materials compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is the "Digital data set describing surficial geology in the conterminous US," produced by the United States Geological Survey (Price and Clawges, 1999). Units are percent. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2018).

This tabular data set represents Dominant geology type (Reed and Bush, 2001) compiled for two spatial components of the NHDPlus version 2 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data for Dominant geology type was produced by Reed and Bush, 2001. Units are percent. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2016).

This U.S. Geological Survey (USGS) data release includes locations for 12,422 USGS streamgages as indexed along the network of streams (flowlines) in NHDPlus Version 2.1 (NHDPlus v2, Moore and Dewald, 2016). The dataset is one of two datasets developed for the Streamgage Watershed InforMation (SWIM) project. This dataset, which is referred to as “SWIM streamgage locations,” was created in support of the second dataset of basin characteristics and disturbance indexes. The streamgages are located in the conterminous United States and have a minimum record length of 20 years of daily streamflow values or at least 20 years of peak flows (USGS National Water Information System (NWIS) database, U.S. Geological Survey, 2016). This dataset has a total of 13,248 streamgages, 826 of which could not be indexed to NHDPlus v2.1. A custom ArcGIS tool was programmed to conduct linear referencing, which moved each point representing a streamgage to intersect with the nearest flowline and calculated the measure along the segment (expressed as a percentage from its downstream end). The tool then performed a series of automated tests to identify potentially inaccurate locations that were, in turn, individually checked. Comments collected during multiple levels of review were retained in raw form to aid future decisions about the accuracy of the streamgage locations along the medium-resolution (1:100,000-scale) NHDPlus stream segments. The results include the unique flowline identifier (COMID) and measure along the flowline, the reach code and measure along its reach (stream feature that consists of one or more flowlines), review notes, plus the latitude and longitude of the stream-referenced location for each streamgage. This designated position along the NHDPlus network may also be referred to as the hydrographic address of the streamgage. References: Falcone, J.A., 2011, GAGES-II: Geospatial Attributes of Gages for Evaluating Streamflow: U.S. Geological Survey dataset, https://doi.org/10.3133/70046617 Moore, R.B., and Dewald, T.G., 2016, The Road to NHDPlus — Advancements in digital stream networks and associated catchments: Journal of the American Water Resources Association, https://doi.org/10.1111/1752-1688.12389 U.S. Geological Survey, 2016, USGS water data for the Nation: U.S. Geological Survey National Water Information System database, accessed October 2016, at https://doi.org/10.5066/F7P55KJN

This tabular data set represents the percent of land cover classes from the new generation of the 2016 National Land Cover Datasets for the years 2001, 2004, 2006, 2008, 2011, 2013, and 2016 compiled for two spatial components of the NHDPlus version 2.1 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2 data suite by the unique identifier COMID. The source data is the "NLCD 2016 Land Cover Conterminous United States" datasets for the years 2001, 2004, 2006, 2008, 2011, 2013, and 2016 produced by the United States Geological Survey (Yang and others, 2018). Units are percent. The "NLCD 2016 Land Cover Conterminous United States" datasets (NLCD 2016) are a 16-class (additional four classes in Alaska only) land cover classification scheme that has been applied consistently across all 50 United States and Puerto Rico at a spatial resolution of 30 meters. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative drainage area. Both approaches use a modified routing database to navigate the NHDPlus reach network to aggregate (accumulate) the metrics derived from the reach catchment scale. (Schwarz and Wieczorek, 2018). First posted: January 20, 2020. Revised: January 25, 2021.

This data release contains drainage basin characteristics and peak-streamflow trend and change-point results for 2,683 U.S. Geological Survey (USGS) streamgages in the conterminous U.S. Data include streamgage identification number, name, drainage area, latitude, longitude, percent urban land use, dam storage, streamgage classification, record completeness status, lag-1 autocorrelation, trend slopes and significance, peaks-over-threshold counts, trends in the numbers of peaks-over-threshold, and change point years and values for median and scale. Also included is an R script containing the Mann-Kendall trend test for three different null hypotheses of the serial structure of the time-series data: independence, short-term persistence, and long-term persistence. Revised - April 8, 2019 (ver. 3.0).

This metadata record documents two comma separated text files of average daily fresh-water withdrawal amounts by NHDPlus v2.1 catchment (COMID) within the conterminous United States for calendar year 2010. County-level reported estimated use of water are specifically reported as groundwater and surface water and are allotted to catchments by a sum of the catchment based on evenly distributing the county total across the number of county land-area pixels. All values are reported as gallons per day. Source county-level data were acquired from Estimated use of water in the United States in 2010 (Maupin and others, 2014; available at https://dx.doi.org/10.3133/cir1405). These datasets can be linked to the NHDPlus version 2.1 data suite by the unique identifier COMID (or comid).

This data release contains trend results computed on the basis of modeled and observed daily streamflows at 502 reference gages across the conterminous U.S. from October 1, 1983 through September 30, 2016. Modeled daily streamflows were computed using the deterministic Precipitation Runoff Modeling System (PRMS), and five statistical techniques: Nearest-Neighbor Drainage Area Ratio (NNDAR), Map-Correlation Drainage Area Ratio (MCDAR), Ordinary Kriging of the logarithms of discharge per unit area (OKDAR), Nearest-Neighbor nonlinear spatial interpolation using flow duration curves (NNQPPQ), and Map-Correlation nonlinear spatial interpolation using flow duration curves (MCQPPQ). Observed daily streamflow data for the study gages were retrieved from the National Water Information System (NWIS). Study gages were selected from among Hydro-Climatic Data Network 2009 (HCDN-2009) gages in the GAGES-II dataset considered to be minimally affected by regulation, diversion, mining, or other anthropogenic activities. Results include trends in annual and monthly means, annual percentiles (1, 5, 10, 25, 50, 75, 90, 95, 99), annual 1-day high, 3-day high, and 7-day low, and annual snowmelt-related runoff timing for a subset of snowmelt dominated basins. Bias and volumetric efficiency statistics between observed and modeled streamflows also are provided.