Hydrogeomorphic Regions in the Chesapeake Bay Watershed.

Generalized lithology (rock type) and physiography based on
geologic formations were used to characterize hydrgeomorphic
regions (HGMR) within the Chesapeake Bay watershed. These
HGMRs were used in conjunction with existing data to assess
the significance of ground-water discharge as a source of
nitrate load to nontidal streams in the Chesapeake Bay
watershed (Bachman and others, 1998). This work is part of
the U.S. Geological Survey's (USGS) Chesapeake Bay initative
to develop an understanding and provide scientific
information for the restoration of the Chesapeake Bay and
its watershed (Phillips and Caughron, 1997).