Riparian Buffer Zones Help Clean Chesapeake
Bay By Sharon
October 24, 2002
For years, riparian buffer zones between farmland and bodies of
water were assumed to be beneficial to waterways. To learn more about how these
zones help the environment, Agricultural
Research Service scientists are looking at riparian zones in the vast
Chesapeake Bay watershed.
ARS soil scientist Gregory McCarty and hydrologist Jonathan
Angier, at the ARS Environmental
Quality Laboratory in Beltsville, Md., are studying the design and function
of these riparian zones with the goal of improving Chesapeake Bay water quality
and helping restore the bay to an even healthier state.
Riparian systems consist of grasses, forest vegetation and
combinations of plants that could slow down surface runoff of unwanted
substances into the bay and potentially reduce surface and groundwater
contaminants. Vegetation takes up some of the excess nutrients, and some is
trapped in the soils.
The research was conducted in a riparian system approximating
Maryland coastal plain farmland. Typical field-applied agricultural chemicals,
particularly nutrients and pesticides, can lead to contaminated drinking water
and other negative impacts on the bay.
The scientists are studying the impact that water moving through
the system has on the effectiveness of the buffer. Water is known to not only
move across the land surface, but also to move vertically between the surface
and the groundwater table.
In the hydrology study, five sampling stations were constructed
along a stream to monitor stream lengths individually and allow comparison with
The researchers found that stream flow characteristics vary in
different sections of the stream. Some areas have more groundwater rising to
the surface than others, and stream flow varies greatly, depending upon the
season and location along the stream. These variations impact how much of the
excess nutrients and chemicals ultimately make it to larger surface waters.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.
For more details on this research, see the
issue of Agricultural Research magazine.