This dataset contains watershed means of estimated percent impervious surfaces for three time periods: 1992, 2002, and 2012. Estimates are based on coefficients derived from comparing land use of the 2012 NAWQA Wall-to-wall Anthropogenic Land-use Trends (NWALT) product to the 2011 National Land Cover Database (NLCD) imperviousness, then applying those coefficients to previous years (1974-2002) of the NWALT dataset.

This metadata report documents a shapefile of watershed boundaries for 84 selected United States Geological Survey (USGS) water quality stations that are part of the Chesapeake Bay non-tidal network (NTN).

This dataset contains values of soils, climate, hydrologic, topographic, and other geographic characteristics such as drainage area. These are considered "static" characteristics, which do not change over the time period of this study.

This dataset contains values of soils, climate, hydrologic, topographic, and other geographic characteristics such as drainage area. These are considered "static" characteristics, which do not change over the time period of this study.

This data release contains three 10-meter resolution GeoTIFFs representing 10-meter (35-foot), 30-meter (100-foot) and 90-meter (300-foot) riparian buffer zones along shorelines, rivers, streams, and other lotic (flowing) water features. The layers are binary, where the value of each cell represents the presence or absence of the buffer zone. In addition, the data release contains shapefile layers that document the extent of corrections that were made to the data to address errors in the stream network (see processing steps section for more details).. The methodology combines various fine-scale input layers, including a 1:24k stream network and Chesapeake Bay 1-meter resolution Land Use/Land Cover to approximate banks of stream channels and waterbodies to better define the riparian zone (CBP, 2023; Hopkins and others, 2020). For shorelines and large rivers, the width of the buffer zone (10, 30, 90 meters) begins at the banks, where land meets water. For finer scale (1:24k) stream features, the buffer zone includes both water and riparian land area, where the buffered width begins at the estimated top of bank. Each 10-meter resolution riparian buffer zone GeoTIFF dataset is contained in an individual .zip file (CBW_riparian_10m_24k_2024.zip, CBW_riparian_30m_24k_2024.zip, CBW_riparian_90m_24k_2024.zip). The shapefile layers that contain the data correction extents are available in the correction_layers.zip file.

This data release contains three 10-meter resolution GeoTIFFs representing 10-meter (35-foot), 30-meter (100-foot) and 90-meter (300-foot) riparian buffer zones along shorelines, rivers, streams, and other lotic (flowing) water features. The layers are binary, where the value of each cell represents the presence or absence of the buffer zone. In addition, the data release contains shapefile layers that document the extent of corrections that were made to the data to address errors in the stream network (see processing steps section for more details).. The methodology combines various fine-scale input layers, including a 1:24k stream network and Chesapeake Bay 1-meter resolution Land Use/Land Cover to approximate banks of stream channels and waterbodies to better define the riparian zone (CBP, 2023; Hopkins and others, 2020). For shorelines and large rivers, the width of the buffer zone (10, 30, 90 meters) begins at the banks, where land meets water. For finer scale (1:24k) stream features, the buffer zone includes both water and riparian land area, where the buffered width begins at the estimated top of bank. Each 10-meter resolution riparian buffer zone GeoTIFF dataset is contained in an individual .zip file (CBW_riparian_10m_24k_2024.zip, CBW_riparian_30m_24k_2024.zip, CBW_riparian_90m_24k_2024.zip). The shapefile layers that contain the data correction extents are available in the correction_layers.zip file.

Input data on watershed drainage area characteristics and stream reach geomorphometry for statistical modeling of floodplains, streambanks, and streambeds in the Chesapeake Bay and Delaware River watersheds of the U.S. Mid-Atlantic. Characteristics include selected upstream accumulated attributes (with divergence routing) describing geology, topography, soils, hydrology, and land use for each NHDPlusV2 stream reach from Wieczorek et al. (2018), and the geomorphometry of the local stream reach summarized from Hopkins et al. (2020). These potential predictors were tested for incorporation into Random Forest statistical models to explain and predict spatial variation in floodplain and streambank flux of sediment, fine sediment, sediment-C, sediment-N, and sediment-P and rates of geomorphic change, and streambed sediment characteristics (d50, cover by fine sediment, cover by fine and sand sediment).

Input data on watershed drainage area characteristics and stream reach geomorphometry for statistical modeling of floodplains, streambanks, and streambeds in the Chesapeake Bay and Delaware River watersheds of the U.S. Mid-Atlantic. Characteristics include selected upstream accumulated attributes (with divergence routing) describing geology, topography, soils, hydrology, and land use for each NHDPlusV2 stream reach from Wieczorek et al. (2018), and the geomorphometry of the local stream reach summarized from Hopkins et al. (2020). These potential predictors were tested for incorporation into Random Forest statistical models to explain and predict spatial variation in floodplain and streambank flux of sediment, fine sediment, sediment-C, sediment-N, and sediment-P and rates of geomorphic change, and streambed sediment characteristics (d50, cover by fine sediment, cover by fine and sand sediment).

Treated effluent from wastewater treatment plants (WWTPs) contains contaminants not fully removed during the treatment process and that may pose environmental health risks when discharged to surface waters. This data release presents inputs for and results from a wastewater reuse model that used data compiled from several sources to calculate the following estimates for each non-tidal, non-coastline, initialized National Hydrography Dataset Version 2.1 (NHDPlus V2) stream segment in the Potomac River watershed: (1) accumulated wastewater as a percent of total streamflow (ACCWW%); and (2) predicted environmental concentrations (PECs, in micrograms per liter) of 69 municipal effluent-derived contaminants. ACCWW% values were calculated for mean-monthly and mean-annual streamflow conditions for both municipal (model results table: Table1_PotomacACCWW_municipal.csv) and industrial-plus-municipal effluent discharges (model results table: Table2_PotomacACCWW_municipal_plus_industrial.csv). PECs were calculated for mean-monthly and mean-annual streamflow conditions for municipal effluent discharges (model results tables: Table3_PotomacPECs.zip, containing comma separated value files of results for mean-monthly and mean-annual conditions). Model estimates at a stream reach of interest represent the combined total upstream wastewater discharges as well as direct discharges into the segment. Model input data included: (1) National Pollutant Discharge Elimination System-permitted facility outfall locations and 2016 average daily effluent discharges linked to a NHDPlus V2 stream Common Identifier (COMID) and facility-specific information on treatment levels and population served per capita (model input table: Table4_PotomacWWTPs.csv); (2) NHDPlus V2 stream geometry and hydrologic attributes (hydrosequence, startflag, terminalfl, divergence, fromnode, tonode, and Enhanced Runoff Method mean-monthly and mean-annual gage-adjusted streamflow and velocity, 1971-2000) (model input table: Table5_PotomacNHDPlusV2.1_flowlines_hydrology.csv); and (3) contaminant-specific data on consumption, fate, and transport compiled from literature sources or estimated from physicochemical properties (see: supplementary table in Larger Work Citation). In Table 4, where information on population served by the facility was missing, this value was estimated by standardizing to 100 gallons per capita per day. Information on population served was only acquired and estimated for municipal facilities. Where treatment level information was missing, the treatment level was assumed to be primary. Ninety-two percent of WWTPs have an assumed treatment as none was reported. R (version 4.0.4) and Python (version 2.7.16) scripts were used to summarize wastewater inputs from outfall locations by COMID and route and accumulate each wastewater and predicted contaminant loads while accounting for in-stream dilution and attenuation of contaminants. Any users of these data should review the entire metadata record and the associated manuscript (see Larger Work Citation). See 'Distribution liability' statements for more information.

Treated effluent from wastewater treatment plants (WWTPs) contains contaminants not fully removed during the treatment process and that may pose environmental health risks when discharged to surface waters. This data release presents inputs for and results from a wastewater reuse model that used data compiled from several sources to calculate the following estimates for each non-tidal, non-coastline, initialized National Hydrography Dataset Version 2.1 (NHDPlus V2) stream segment in the Potomac River watershed: (1) accumulated wastewater as a percent of total streamflow (ACCWW%); and (2) predicted environmental concentrations (PECs, in micrograms per liter) of 69 municipal effluent-derived contaminants. ACCWW% values were calculated for mean-monthly and mean-annual streamflow conditions for both municipal (model results table: Table1_PotomacACCWW_municipal.csv) and industrial-plus-municipal effluent discharges (model results table: Table2_PotomacACCWW_municipal_plus_industrial.csv). PECs were calculated for mean-monthly and mean-annual streamflow conditions for municipal effluent discharges (model results tables: Table3_PotomacPECs.zip, containing comma separated value files of results for mean-monthly and mean-annual conditions). Model estimates at a stream reach of interest represent the combined total upstream wastewater discharges as well as direct discharges into the segment. Model input data included: (1) National Pollutant Discharge Elimination System-permitted facility outfall locations and 2016 average daily effluent discharges linked to a NHDPlus V2 stream Common Identifier (COMID) and facility-specific information on treatment levels and population served per capita (model input table: Table4_PotomacWWTPs.csv); (2) NHDPlus V2 stream geometry and hydrologic attributes (hydrosequence, startflag, terminalfl, divergence, fromnode, tonode, and Enhanced Runoff Method mean-monthly and mean-annual gage-adjusted streamflow and velocity, 1971-2000) (model input table: Table5_PotomacNHDPlusV2.1_flowlines_hydrology.csv); and (3) contaminant-specific data on consumption, fate, and transport compiled from literature sources or estimated from physicochemical properties (see: supplementary table in Larger Work Citation). In Table 4, where information on population served by the facility was missing, this value was estimated by standardizing to 100 gallons per capita per day. Information on population served was only acquired and estimated for municipal facilities. Where treatment level information was missing, the treatment level was assumed to be primary. Ninety-two percent of WWTPs have an assumed treatment as none was reported. R (version 4.0.4) and Python (version 2.7.16) scripts were used to summarize wastewater inputs from outfall locations by COMID and route and accumulate each wastewater and predicted contaminant loads while accounting for in-stream dilution and attenuation of contaminants. Any users of these data should review the entire metadata record and the associated manuscript (see Larger Work Citation). See 'Distribution liability' statements for more information.