This data set is an ArcGIS shapefile depicting land segments in the Chesapeake Bay Watershed and adjacent states of New York, Pennsylvania, Maryland, West Virginia, Delaware, Virginia, North Carolina, and Tennessee. Land segmentation was based on county boundaries represented by a 1:100,000-scale digital dataset. Fifty of the 254 counties and incorporated cities in the model region were divided on the basis of physiography and topography, producing a total of 310 land segments. The data are projected to the UTM grid coordinate system - Zone 18 NAD27.

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.

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 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)

These data include estimates of landcover and land use characteristics including high phytoestrogen crop cover, estimated pesticide applications, EPA PFAS facilities, nutrients from biosolids, and select climate (temperature and precipitation) variables summarized for several fish health sites in the eastern United States.

These data include estimates of landcover and land use characteristics including high phytoestrogen crop cover, estimated pesticide applications, EPA PFAS facilities, nutrients from biosolids, and select climate (temperature and precipitation) variables summarized for several fish health sites in the eastern United States.

Freshwater salinization is an emerging issue for freshwater environments in the Chesapeake Bay, USA region. Salinization is often described by measurements of specific conductance (SC). This data release contains specific conductance observations collected by multiple regional agencies for streams within the Chesapeake Bay Watershed. This inventory compiles and harmonizes data from the Water Quality Portal (WQP), which is a data repository developed by the National Water Quality Monitoring Council and supported by the U.S. Environmental Protection Agency and U.S. Geological Survey, and the U.S. Geological Survey National Water Information System (NWIS). Both discrete measures of SC, which are single measures taken on a particular time and day, and continuous measures of SC, which are repeated measures of SC taken at regular, short intervals, such as 15-minute or hourly intervals, were compiled for this data release. The discrete data were also processed to screen out non-relevant observations and harmonize units. The WQP uses "MonitoringLocationIdentifier" to identify each unique site and monitoring activities, and this term is used throughout the data release to differentiate among unique sites and monitoring activities as well. The data release includes four items: 1. ["Site_inventory_for_specific_conductance_measures.csv"]: This is a site inventory of all locations where SC data had been collected and compiled for the data release. This file includes information on the monitoring location (coordinates, state, and county), the organization responsible for the data collection, the type of data available (discrete, continuous, or both) and its unique monitoring location and activity. 2. ["Discrete_specific_conductance_results.txt"]: This file contains all discrete SC observations. Identifying information (coordinates, monitoring location name and identifier), along with the observation value, units, and multiple flagging columns which denoted whether any changes were made to the observation or units during the processing steps. Full details are included in the "readme_file_for_Ches_Bay_specific_conductance_inventory.pdf" file. 3. ["Continuous_specific_conductance_results.zip"]: This zipped folder contains 89 .csv files for all the continuous USGS SC data available in the Chesapeake Bay watershed. Each file name includes each unique MonitoringLocationIdentifier. 4. ["readme_file_for_Ches_Bay_specific_conductance_inventory.pdf"]: This document describes all the processing and harmonization steps to generate the site inventory and discrete SC dataset, and for downloading the high frequency SC datasets.

Summarization of the University of Massachusetts Landscape Ecology Lab Designing Sustainable Landscapes (DSL) datasets with the Spatial Hydro-Ecological Decision System (SHEDS) framework. These DSL data were summarized using the local and upstream total accumulation methods within SHEDS. The result are two sets of data, a continuous dataset and a discrete dataset. The continuous dataset contains the average value for the local SHEDS catchments and the area-weighted sums of the averages for the local and all upstream SHEDS catchments for all continuous variables in the DSL dataset. The discrete dataset contains the area in square meters covered by each class within all discrete variables in the DSL dataset for the local SHEDS catchments along with the area-weighted sum of the local and all upstream SHEDS catchment values.

Summarization of the University of Massachusetts Landscape Ecology Lab Designing Sustainable Landscapes (DSL) datasets with the Spatial Hydro-Ecological Decision System (SHEDS) framework. These DSL data were summarized using the local and upstream total accumulation methods within SHEDS. The result are two sets of data, a continuous dataset and a discrete dataset. The continuous dataset contains the average value for the local SHEDS catchments and the area-weighted sums of the averages for the local and all upstream SHEDS catchments for all continuous variables in the DSL dataset. The discrete dataset contains the area in square meters covered by each class within all discrete variables in the DSL dataset for the local SHEDS catchments along with the area-weighted sum of the local and all upstream SHEDS catchment values.

This data release links habitat assessment sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks using the hydrolink methodology. Linked habitat sites are those compiled by the Interstate Commission on the Potomac River Basin (ICPRB) during creation of the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) for benthic macroinvertebrates (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.