Ephemeral stream water contributions to United States drainage networks

Results from our CONUS ephemeral stream modeling study. Included in this release is a set of csv files for each CONUS drainage basin (USGS HUC level 4 basins). These lookup tables can be joined to NHD-HR hydrography (https://www.usgs.gov/national-hydrography/nhdplus-high-resolution). CSV columns are as follows:

NHDPlusID: NHD-HR reach ID. Use this to join to hydrography shapefiles.

perenniality: Result of our ephemeral classification model (see paper for methods).

percQEph_reach: Main model result. See equation S1 in paper.

Some notes:

Note that continental-scale models prioritize capturing broad patterns across large domains, so we caution against over-interpreting results for individual river reaches.

Great Lakes are not included, though the model does route through the lakes for topological consistency.

Foreign streams are recast as 'non-ephemeral' to be copacetic with figures in the paper. See paper for more details.

Some reaches present in the NHD-HR are not included in our results for a variety of reasons. See paper for details.