“ChesBay 24k – HU": Human Related Data Summaries for the Chesapeake Bay Watershed Within NHD Plus HR catchments

These tabular data are summaries of human related landscape variables within catchments of the Chesapeake Bay watershed using the Xstrm methodology at 1:24,000 scale. Variables being counted as human related include agriculture, barriers, road density and road/stream crossing data. Outputs consist of tabular comma-separated values files (CSVs) for both local catchment and network summaries linked to the National Hydrography Dataset Plus High-Resolution (NHDPlus HR) framework by NHDPlus ID. Local catchments are defined as the single catchment the data is summarized within. Network accumulation summaries were completed for each of the local catchments and their network connected upstream and/or downstream catchments. The summarized data tables are structured as a single column representing the catchment id values (ie. nhdplusid) and the remaining columns consisting of the summarized variables.
 
For a full description of the variables included within these summaries see xstrm_nhdhr_human_chesapeake_baywide_datadictionary.csv in the attached files. For information about the summarization process parameters, see xstrm_nhdhr_cbay_human_summary_expanded_metadata.csv.
 
The Xstrm local summary methodology takes either raster or point data as input then summarizes those data by "zones", in this case the NHDPlus HR catchments. Network summaries then take the results from the local summaries and calculates the desired network summary statistic for the local catchment and its respective upstream or downstream network-connected catchments.
 
As a note concerning use of these data, any rasters summarized within this process only had their cells included within a catchment if the center of the raster cell fell within the catchment boundary. However, the resolution of the input raster data for these summaries must be considered to provide adequate coverage of the summary catchments using this option. If an alternative coverage of a catchment is desired (even if a raster cell only is minimally included within the catchment) then it is recommended to rerun the Xstrm summary process with the "All Touched" option set to True.

Further information on the Xstrm summary process can be found at the Xstrm software release pages:
Xstrm: Wieferich, D.J., Williams, B., Falgout, J.T., Foks, N.L. 2021. xstrm. U.S. Geological Survey software release. https://doi.org/10.5066/P9P8P7Z0.
Xstrm Local: Wieferich, D.J., Gressler B., Krause K., Wieczorek M., McDonald, S. 2022. xstrm_local Version-1.1.0. U.S. Geological Survey software release. https://doi.org/10.5066/P98BOGI9.