Glossary

EPSG

A catalog of coordinate reference systems. Providing an EPSG number is a shortcut for the specification of the coordinate system. For example EPSG:4326 corresponds to WGS 84, the World Geodetic System 1984 used in GPS. See epsg.io to discover coordinate systems worldwide.

HUC - Hydrologic Unit Code

In the United States, watersheds are delineated by USGS using a nationwide, hierarchical system. Each hydrologic unit is assigned a 2-digit to 12-digit number that uniquely identifies the respective region, subregion, basin, sub-basin, watershed or subwatershed, as shown below. Learn more at Hydrologic Unit Codes (HUCs) Explained.

Hydrologic Unit Structure illustrated

The Riverscapes Data Exchange treats the HUC identifier as a special attribute of projects for ease of searching and identifying projects using this code. For this reason Riverscapes projects outside the USA may wish to use this field as a unique identifier.

rscli

The command-line interface for the Data Exchange. See rscli documentation.