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Summary of USGS Projects Related to Understanding the Sources and Impact
of Sediment on Water Clarity and Submerged Aquatic Vegetation in the Chesapeake
Bay
Summaries | Partners
Excess sediment is having an adverse effect on the living resources and
associated habitat of the Chesapeake Bay and its watershed. The USGS is
conducting studies to help the Chesapeake Bay Program protect and restore
stream corridors and reduce sediment loads to the Bay that impact water
clarity and submerged aquatic vegetation (SAV).
The USGS is addressing several objectives related to sediment and its
impact on the Bay and its watershed: (a) defining the watershed sources,
transport, and delivery of sediment to the Bay, (b) understanding the
relation between sediment sources, deposition, transport and water clarity,
and biota in the Bay and tidal tributaries, (c) understanding the factors
affecting SAV and its habitat, and (d) developing decision-support systems
to assist in the creation of sediment-reduction strategies. The USGS interacts
with the CBP through co-leadership of the CBP Sediment Workgroup, participation
in the CBP workgroups related to tidal water quality and SAV, and by providing
results from several on-going projects
Project Summaries
Sources and Transport of Sediment in the Chesapeake Bay Watershed
The objective of this project, which is being conducted in cooperation
with the CBP, is to identify sources of sediment to rivers in the Chesapeake
Bay watershed. The project is completing an analysis of historical data
to identify the sediment concentrations, yields, and loads in major basins
of the Bay watershed. A regional analysis of factors affecting sediment
concentrations, yields, and loads in major basins of the Bay watershed
will be conducted next year. The project is experimenting with different
types of tracers to identify sediment sources to streams in smaller watersheds.
The tracers will help to determine whether sediment transported in rivers
is from soil erosion or loss of streambanks. The studies are being carried
out in parts of the Pocomoke, Conestoga, and Mattawoman (a tributary of
the Potomac River) Basins. (Contact: Allen Gellis, agellis@usgs.gov).
River Input Monitoring
This project, which is carried out in cooperation with the Maryland Department
of Natural Resources and the Virginia Department of Environmental Quality,
is designed to measure the concentrations, estimate loads, and compute
trends of nutrients and sediment entering the Bay from its major rivers.
An increased number of parameters, such as grain-size analysis and organic
content of sediment, have been added at the nine River-Input monitoring
stations in the Bay watershed. These parameters will help improve calibration
of both the watershed and estuary water-quality models. (Contacts Mick
Senus (MD) mpsenus@usgs.gov and
Doug Moyer (VA) dlmoyer@usgs.gov.
River Observations for Management Applications (ROMA)
Analysis of erosion and sediment budgets in the Susquehanna Basin is being
conducted under the ROMA project. A sediment erosion index is being developed
for the Susquehanna Basin based on interpretation of Be10 from samples
collected at 22 sites. A more detailed stratigraphic analysis is being
conducted in the Little Conestoga Basin to understand erosion rates and
their relation to land use. An assessment of land-use change, analysis
of spatial data, and sediment modeling is being conducted by the USGS
Geography Discipline to relate erosion to land-use changes in the basin.
Results from this project should help identify sources of sediment that
enter the Susquehanna reservoirs and eventually the Chesapeake Bay. (Contacts:
Milan Pavich, mpavich@usgs.gov and
Robert Clark, bclark@usgs.gov)
Storage of Sediment on Flood Plains
The objective of this project is to monitor Coastal Plain sites for sediment
trapping along Coastal Plain tributaries. This information is helpful
in understanding how much of the sediment from the Coastal Plain reaches
the Bay and its tidal tributaries. An analysis and report of sediment
trapping is being completed. More extensive fieldwork to supplement the
investigation of sediment source tracers is being conducted in the Pocomoke,
Conestoga, and Mattawoman Basins. (Contact: Cliff Hupp, crhupp@usgs.gov)
Atlantic Estuaries
This objective of this project is to document and examine factors affecting
the changes in the Bay ecosystem over different time scales. The project
has several tasks related to sediment including: (a) mapping depositional
and erosion features that influence sediment delivery to the Bay; (b)
determining the contribution of bluff erosion and wetland deterioration
to sedimentation; (c) evaluating the impacts of land-use changes on sediment
deposition rates and ecology over different time scales; (d) defining
the sources of sediment and subsequent deposition in the Bay using isotopic
tracers; and (f) identifying factors affecting water clarity using remote
sensing. This work is being carried out primarily in the Pocomoke and
Nomini (a tributary of the Potomac) tidal areas. (Primary Contacts: Debra
Willard, dwillard@usgs.gov and
Tom Cronin, tcronin@usgs.gov).
Cycling of Nutrients and Sediment
The objective of this project is to understand the delivery of nutrients
and sediment to the Chesapeake Bay. The project has focused on nutrient
delivery in several Coastal Plain watersheds (Pocomoke, Popes Creek, and
Nomini Creek). In addition to addressing nutrient transport, analysis
of the factors affecting turbidity and sediment sources is being carried
out in the tidal part of these watersheds. (Contact: Owen Bricker, obricker@usgs.gov).
The Relation Between River Trends, Water Clarity, and SAV
The objective of this project is to examine the relation between regional
patterns in tidal water-clarity conditions and river discharge and sediment
loads. Statistical analysis is being conducted for each of the major tidal
tributaries to help identify the influence of riverine sediment loads
on water clarity and potential effects on the occurrence of SAV. A report
of the analysis of being prepared in FY04. (Contact: Jurate Landwehr,
jmlandwe@usgs.gov.)
Chesapeake Bay SAV Linkages
The objective of this project is to develop an understanding of a) the
factors leading to change in SAV distribution and abundance, and b) the
effect of vegetation on water quality, sediment nutrients, nutrient transport,
and hydrology in estuarine and freshwater environments. The project focuses
on several study sites in the Potomac Estuary, where the techniques to
relate water clarity, nutrients in sediment, and SAV are being carried
out. The information will be useful to help understand SAV response to
improved water clarity in the Bay. (Contact: Nancy Rybicki, nrybicki@usgs.gov).
Development of Decision Support Tools
The objective of this project is to provide GIS analysis of nutrient and
sediment information and to develop tools to transfer selected data to
decision makers. The project is focusing on development of a WWW-based
decision-support tool that identifies areas of high sediment and nutrient
contribution to the Bay that impact water clarity based on existing information
and results of USGS studies. (Contacts: John Brakebill, jwbrakeb@usgs.gov
and Scott Phillips, swphilli@usgs.gov)
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Partners
The USGS is interacting with partners through the CBP Sediment Workgroup.
A study to identify sediment sources in the watershed is a joint effort
between USGS and the CBP. Work to address sediment erosion of shorelines
and deposition in the estuaries of the bay is being conducted with the Maryland
Geologic Survey. The causes of shoreline erosion in the
Blackwater National Wildlife Refuge are being addressed in cooperation with the
U.S. Fish and Wildlife Service (USFWS). Monitoring efforts for sediment in rivers are
being conducted with Maryland Department of Natural Resources (MD DNR),
Virginia Department of Environmental Quality (VA DEQ), and the
Susquehanna River Basin Commission (SRBC). The relation of sediment to water clarity
is being addressed through remote sensing in cooperation with the
National Aeronautics and Space Administration (NASA). The USGS is an active member
of the Living Resources Workgroup of the CBP, and works closely with the
MD DNR, to collect water-quality data at SAV sites in the Potomac, and the
Virginia Institute of Marine Sciences (VIMS), which is documenting the occurrence
of SAV in other parts of the Bay.
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