Hydrologic landscape regions of the United States

Hydrologic landscape regions (HLRs) in the United States were delineated by
using geographic information system (GIS) tools and statistical methods
including principal components and cluster analyses. The GIS and statistical
analyses were applied to land-surface form, geologic texture (permeability of
the soil and bedrock), and climate variables that describe the physical and
climatic setting of 43,931 small (roughly 200 square kilometers) watersheds
in the United States. The analyses then grouped the watersheds into 20
noncontiguous regions (the HLRs) on the basis of similarities in land-surface
form, geologic texture, and climate characteristics.

This hydrologic landscape regions dataset contains for each of the 43,931
watersheds the (1) watershed identification number, (2) land-surface form,
geologic texture, and climate characteristics for each watershed, and (3)
hydrologic landscape region number for each watershed.