Predictions from statistical modeling of floodplains, streambanks, and streambeds in the Chesapeake Bay and Delaware River watersheds of the U.S. Mid-Atlantic. Random Forest statistical models using either 1) characteristics of upstream drainage area, or 2) characteristics of upstream drainage area (Wieczorek et al. 2018, https://doi.org/10.5066/f7765d7v) and reach geomorphometry (Hopkins et al. 2020, https://doi.org/10.5066/P9RQJPT1), were used to explain and predict spatial variation in measured 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) (Noe et al. 2020, https://doi.org/10.5066/P9QLJYPX). These predictions were compared to published estimates of upland erosion and delivery of upland erosion to streams (Chesapeake Bay Program, https://cast.chesapeakebay.net/Documentation/ModelDocumentation), and catchment export (Ator 2019, https://doi.org/10.3133/sir20195118).

Geomorphometry for Streams and Floodplains in the Chesapeake and Delaware Watersheds was generated as part of the project Quantifying Floodplain Ecological Processes and Ecosystem Services in the Delaware River Watershed funded through the William Penn Foundation's Delaware Watershed Research fund. This dataset contains geomorphometry for streams and floodplains in the Chesapeake and Delaware River watersheds. Geomorphometry is a quantitative representation of landscape surface form (e.g., channel width and depth) obtained from digital elevation models (DEMs). This dataset contains geomorphometry derived from running 3-m DEMs through the Floodplain and Channel Evaluation Tool (FACET) version 0.1.0. FACET generates shapefiles and rasters of the stream network, cross sections, streambank point locations, floodplain extent, height above nearest drainage (HAND), and reach-scale summaries of bank height, channel width, floodplain width, and a suite of other metrics outlined in the data dictionary. These data were generated to aid in modeling the amount of sediment and nutrients trapped on floodplains or eroded from streambanks in the Chesapeake and Delaware River watersheds. Files are organized into folders by hydrologic unit code (HUC) for subbasins within the Chesapeake and Delaware watersheds. Each folder contains the following files within the main folder and a sub folder called "post processing." XXXX folder, where XXXX is a 4-digit HUC: Main [folder_name] files, where “folder name” is an 8- or 10-digit HUC: [folder_name]_bankpixels.tif [folder_name]_dem.tif [folder_name]_floodplain.tif [folder_name]_hand.tif [folder_name]_mask.shp [folder_name]_network.shp [folder_name]_network.tif [folder_name]_channel_xns.shp Post-processing folder files: bankpoints_1D_metrics.shp bankpoints_1D_metrics_all_stats.dbf channel_floodplain_2D_metrics.shp channel_floodplain_2D_metrics_all_stats.dbf floodplain_xns_1D_metrics.shp floodplain_xns_1D_metrics_all_stats.dbf Each file and associated attributes are described in the data dictionary listed in the Attached Files section. Merged files spanning the entire study area are included within the Child Item page called Chesapeake and Delaware Basin Combined Files. The combined files include a shapefile with the stream network and the floodplain extent, as well as a post-processing table with select stream and floodplain metrics.

This child item contains input files and output files for 857 rural, unregulated streamgages in and near Virginia and West Virginia processed using PeakFQ v7.5.1 for the 2025 flood frequency analysis. Additionally, results were extracted from the input and output files for in each streamgage and summaries were generated. This dataset includes: 1) "Station.zip": A subdirectory containing published annual peaks in WATSTORE format (*.pkf), specifications used for processing in Program Specification File format (*.psf), the output text file containing computation results (*.prt), and the export text file (*exp). The files within these subfolders are aggregated by 2-digit downstream order part number (01, 02, and 03) due to the limitations of maximum number of records PeakFQ v7.5.1 can process at once. At-station skew was used to compute these results. 2) "Weighted.zip": A subdirectory containing published annual peaks in WATSTORE format (*.pkf), specifications used for processing in Program Specification File format (*.psf), the output text file containing computation results (*.prt), and the export text file (*exp). The files within these subfolders are aggregated by 2-digit downstream order part number (01, 02, and 03) due to the limitations of maximum number of records PeakFQ v7.5.1 can process at once. Weighted regional skew was used to compute these results. 3) Table_3_Unregulated_Frequency_Specs.txt: Contains a summary of the specifications and statistics for at-station frequency analyses for 857 streamgages on unregulated streams in and near Virginia and West Virginia for annual peak streamflows including period of record, record length, skew specifications, thresholds and counts of PILFs, value, significance, and slope of the Mann-Kendall trend test; mean, median, and station skew for annual peak streamflows analyzed; regional skew; and MSE of station and regional skew. 4) Table_4_Unregulated_Frequency_Summary.txt: Contains a summary of the results of valid at-station frequency analyses for 813 streamgages on unregulated streams in and near Virginia and West Virginia for annual peak streamflows including flow and variance values for the 0.995, 0.667, 0.5, 0.2, 0.1, 0.04, 0.02, 0.01, 0.005, and 0.002 annual exceedance probabilities.A combination of at-station skew and weighted regional skew was used were appropriate to compute these results.

U. S. Geological Survey (USGS) scientists completed a data collection campaign from the 3rd of April to the 23rd of June in 2023, using various methods to record geomorphic and habitat indicators throughout southern Pennsylvania and northern Maryland. Field methods included GNSS surveys, gravelometer-based pebble count readings, visual assessments, and riparian analyses. These data contain all recorded field metrics from the in-channel habitat assessment as well as the Riparian Rapid assessment. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Denitrification measurements and ecosystem attributes in hummock-hollow microtopography of tidal freshwater forested wetlands along longitudinal riverine positions (upper, middle, and lower tidal river sites, and nearby upstream nontidal forested floodplains) of the adjoining Pamunkey and Mattaponi Rivers, Virginia.

This dataset includes literature-derived ecological data from tidal saline wetlands across the United States, Canada, and Mexico for the following ecosystem properties: canopy height, aboveground biomass, productivity, soil carbon density, and soil carbon accumulation rates.

The Chesapeake Bay Hyper-Resolution Hydrography Database is intended to facilitate analysis of the landscape in the Chesapeake Bay watershed through identification of headwater and other low-order streams or drainage features (e.g. ditches) that, to date, may be absent from existing hydrography data products. A full description of the methodology and accuracy assessment is provided in the accompanying report titled: "Hydrography Mapping Supporting Modeling and Targeted Conservation: Project Overview and Lessons Learned". The data products were developed by the Chesapeake Conservancy and the University of Maryland Baltimore County (UMBC) as part of a 6-year Cooperative Agreement between the Chesapeake Conservancy and the U.S. Environmental Protection Agency (EPA) and a separate Interagency Agreement between the USGS and the EPA to provide geospatial support to the Chesapeake Bay Program Office. The data release is structured by eight-digit level hydrologic unit codes (HUC8) for the Chesapeake Bay watershed. Each HUC8 contains seven files (see below) and uses the following nomenclature: where HUC_ID and WATERSHED_NAME are placeholders for HUC8 ID(s), and local watershed name(s) (e.g., "Hydrographic Datasets for Hydrologic Unit 02050101 - Upper Susquehanna") Data Release Structure: Project Overview and Lessons Learned.pdf (Project overivew, methodology and accuracy assessment) huc_[HUC_ID]_streamLine.zip (Stream Lines) huc_[HUC_ID]_streamPoly.zip (Stream Polygons) huc_[HUC_ID]_agDitches.zip (Agricultural Ditches) huc_[HUC_ID]_rdDitches.zip (Road Ditches) huc_[HUC_ID]_geomorphon1m.tif (Geomorphon 1-meter) huc_[HUC_ID]_geomorphon10m.tif (Geomorphon 10-meter) metadata_[HUC_ID].xml (metadata xml)

The assessment of different aspects of hydromorphic conditions through time and space may assist in explaining the various stressors contributing to stream condition such as habitat alteration. This dataset provides results for status and trends of hydromorphology (the interplay of geomorphology, hydraulics, and physical habitat) of streams and rivers in the Chesapeake Bay watershed. These two separate analyses for status and trends in hydromorphology are derived from: analysis of field-based rapid habitat metrics collected by multiple jurisdictions during habitat surveys; and specific gage analyses using data collected during routine streamflow measurements at USGS streamgages. Results from the rapid habitat and stream gage status and trend analyses are provided below in the two respective Child Items. Detailed data preparation information, analytical methods and results are presented and discussed in the associated Scientific Investigative Report (https://doi.org/10.3133/sir20255072).

The Chesapeake Bay Hyper-Resolution Hydrography Database is intended to facilitate analysis of the landscape in the Chesapeake Bay watershed through identification of headwater and other low-order streams or drainage features (e.g. ditches) that, to date, may be absent from existing hydrography data products. A full description of the methodology and accuracy assessment is provided in the accompanying report titled: "Hydrography Mapping Supporting Modeling and Targeted Conservation: Project Overview and Lessons Learned". The data products were developed by the Chesapeake Conservancy and the University of Maryland Baltimore County (UMBC) as part of a 6-year Cooperative Agreement between the Chesapeake Conservancy and the U.S. Environmental Protection Agency (EPA) and a separate Interagency Agreement between the USGS and the EPA to provide geospatial support to the Chesapeake Bay Program Office. The data release is structured by eight-digit level hydrologic unit codes (HUC8) for the Chesapeake Bay watershed. Each HUC8 contains seven files (see below) and uses the following nomenclature: where HUC_ID and WATERSHED_NAME are placeholders for HUC8 ID(s), and local watershed name(s) (e.g., "Hydrographic Datasets for Hydrologic Unit 02050101 - Upper Susquehanna") Data Release Structure: Project Overview and Lessons Learned.pdf (Project overivew, methodology and accuracy assessment) huc_[HUC_ID]_streamLine.zip (Stream Lines) huc_[HUC_ID]_streamPoly.zip (Stream Polygons) huc_[HUC_ID]_agDitches.zip (Agricultural Ditches) huc_[HUC_ID]_rdDitches.zip (Road Ditches) huc_[HUC_ID]_geomorphon1m.tif (Geomorphon 1-meter) huc_[HUC_ID]_geomorphon10m.tif (Geomorphon 10-meter) metadata_[HUC_ID].xml (metadata xml)

This data release includes a data-processing script, data products, and associated metadata for a study to model the hydrology of several hundred vernal pools (seasonal pools or ephemeral wetlands) across the northeastern United States. The dataset described in this metadata document consists of several components: (1) pool-specific attributes including name and geographic location, (2) time-varying inundation observations collected between May 2004 and July 2016; (3) landscape attributes associated with pool locations including geologic, soil, and landcover characteristics; (4) short- and medium-term weather and climate variables for time periods (for example, 5-days and 6-months) immediately preceding the dates of inundation observations; and (5) long-term (30-year average) climate variables associated with pool locations.