(An ARS Benchmark Research
Watershed, one of 24 CEAP watershed projects.)
Characteristics
Goodwin
Creek drains 2132 ha in
Environmental Impacts
1.
Water Quality: Runoff contaminated with sediment, phosphorus, and fecal
coliforms.
2.
Fish and Wildlife Habitat: Aquatic habitat impaired by unstable substrate, lack
of pool habitat, and by highly suspended sediment concentrations, which has caused
reduced sizes and species composition of fish and invertebrates.
3.
Soil Quality: Soil quality has been adversely affected by excessive erosion.
Management Practices
1.
Conservation reserve program (CRP, 327).
2.
Channel stabilization (584)
3.
Grade stabilization structures (410)
4.
Stream habitat improvement and management (395)
5.
Channel bank vegetation (322)
Research Objectives
Evaluate
watershed and channel responses to conservation practices over the period of
record of the watershed. Conservation practices on this watershed include
conversion of erodible cropland to the conservation reserve program (CRP,327),
channel stabilization (584), grade stabilization structures (410), stream
habitat improvement and management (395), channel bank vegetation (322).
Approaches
The
research related to CEAP on Goodwin Creek will combine field, laboratory, and
computer modeling components. The field and laboratory studies will concentrate
on the accurate measurement and prediction of sediment transport rates by the
channels of the watershed. This capability is critical for the accurate
determination of sediment amounts, sources, and contaminants. A key factor that
will be studied on Goodwin Creek is the determination of the sources of
sediment and its effects on the environment. Previous studies have shown that
channel erosion provides a significant contribution to the total sediment load
of the watershed. Samples of fine sediment will be automatically collected at
the measurement stations of the watershed. These will be combined with experimental measurements of sediment
concentration collected using acoustic backscattering to yield a record of
sediment load. Soil properties of the watershed will be quantified and used for
sediment source determinations and modeling inputs.
Completed
(historical) studies have documented the effects of channel and bank
stabilization on stream fishes and invertebrates. In particular, populations
within reaches stabilized using traditional structures and reaches with
structures modified to produce more pool habitat have been compared over 3-10
year periods. Some of these studies have documented the temporal variation in
bed material size with channel erosion and deposition and the hydraulic
retention at baseflow of reaches with and without small beaver dams.
Sediment
source information will be determined in the suspended sediment of Goodwin
Creek during runoff events using activities of 7Be
and 210Pb. Activities of 7Be
and 210Pb are measured from precipitation, soil, bank,
and suspended sediments in the Goodwin Creek watershed. Gamma spectroscopy is
used to determine the activities of 7Be
and 210Pb in all samples. Suspended sediment in Goodwin
Creek is a mixture of landscape derived and bank derived sediment. The
activities of 7Be and 210Pb of
the surface soils will be significantly higher than corresponding activities of
the bank sediments. The radionuclide signature of the suspended sediment will
lie intermediate along a mixing line between the signatures of the two
end-member sources of sediment. Thus, fine suspended sediment in Goodwin Creek
has an intermediate radionuclide signature that is quantified in terms of the
relative contribution of landscape derived and bank sediment. This data will be
valuable in evaluating source information from CONCEPTS and AnnAGNPS.
Continuous
monitoring of hydrologic, hydraulic and geotechnical controls of streambank
failures is being conducted along an active meander bend and at edge of field
gullies. The data from these studies are used to enhance a deterministic model
of bank stability, to support finite-element modeling of seepage, and to
develop a predictive model of gully migration and erosion. Top-bank vegetative
treatments are being monitored to quantify the hydrologic and mechanical effects
of riparian vegetation on bank stability and their potential role as a
conservation measure. These efforts will provide data for enhancements to
routines in CONCEPTS and AnnAGNPS.
The historical
and newly acquired conservation data from NRCS will be used with AnnAGNPS and
CONCEPTS to evaluate watershed and channel responses to conservation practices
over the period of record of the watershed. The simulated values will be
verified using field-collected data on sediment concentrations, sediment
sources, and bank retreat rates. This will assure that the models are
adequately representing the processes acting on the watershed. Model
simulations using AnnAGNPS and CONCEPTS will be made to evaluate different
scenarios of conservation practices and sources of sediment. Changes in water
quality parameters from 1985 through 2005 will be evaluated in terms of the
conservation practices used on the watershed.
Selected References
1.
Alonso, C. V, and R.L. Bingner. 2000. Goodwin Creek Experimental Watershed: A
unique field laboratory. ASCE, Journal of Hydraulic Engineering, 126(3):
174-177.
2.
Kuhnle, R. A., Simon, A., Knight, S. S. 2001. Developing Linkages Between
Sediment Load and Biological Impairment for Clean Sediment TMDLs. Wetlands
Engineering and River Restoration Conference, ASCE, Reno, Nevada, August.
3.
Langendoen, E. J., R. L. Bingner, C. V. Alonso, and A. Simon. 2001.
Processbased stream-riparian modeling system to assess stream TMDLs. In
Proceedings of the Sediment: Monitoring, Modeling, and Managing, 7th Federal
Interagency Sedimentation Conference,
4.
Pollen, N., Simon, A., and Collison, A. 2004. Advances in assessing the
mechanical and hydrologic effects of riparian vegetation on streambank
stability. In Riparian Vegetation and
Fluvial Geomorphology. Bennett, S. and A. Simon (Eds.). Water Science and
Application 8, American Geophysical Union, pp. 125-140.
5.
Simon, A., Curini, A., Darby, S.E., and Langendoen, E.J., 2000, Bank and
nearbank processes in an incised channel. Geomorphology, v. 35 193-217.
6.
Steiner, M., J.A. Smith, S.J. Burges, L.C. Sieck, and C.V. Alonso. 2002. How
much rain reaches the surface? Lessons learned from very high-resolution
observations in the Goodwin Creek watershed. Proceedings, 16th Conference
on Hydrology, American Meteorological Society,
7.
Wood, A.L., Simon, A.,
Collaborators and Cooperating
Agencies and Groups
NRCS
has established two SCAN (soil climate analysis network) sites on Goodwin
Creek. These sites provide longterm geographically distributed soil climatology
data. One wooded and one pasture site were chosen where soil moisture and
temperature at several different depths were being measured.
NOAA
has identified Goodwin Creek for co-location of solar surface
radiation budget (SURFRAD) and surface thermal energy and CO2 exchange
(FLUXNET) monitoring stations as part of nationwide networks. Data on those
parameters is collected on a continuous basis and related to other watershed
processes.
University
of Mississippi National Center for Physical Acoustics (NCPA) has
been involved in ongoing cooperative projects to use acoustics to improve the
measurement of sediment transport on Goodwin Creek.