1. An Examination of Winyah Bay,South Carolina Under Two Different Flow Conditions Kathryn Benson CE 394K GIS in Water Resources University of Texas at Austin Fall 2002

2. Where to start? Data Acquisition from the University of South Carolina EPA River Reach File-Region 03 USGS Hydrologic Cataloging Unit OBJECTIVE To examine the mixing characteristics of Winyah Bay, South Carolina under two different streamflow conditions

3. Watershed Characteristics Second largest watershed on the Atlantic Coast 3 States 12 HUCS

4. Streamflow Conditions Five Main Rivers flow into Winyah Bay Define streamflow for two days of sampling High vs. average flow conditions due to snowmelt Use of Time Series Function

6. WINYAH BAY, SC  68.3 km 2 or 26.3 mi 2  Six sampling sites per day for ebbing tide (freshwater towards ocean)  Interface between freshwater and saltwater is extended over approximately a 10 km area from the rivers to the mouth of Winyah Bay (Zabawa, 1979)  Mixing point for low flow is WB499.9 Partially Mixed Estuary  Mixing point for high flow is WB200.13 River Dominated Estuary

9. CTD NISKIN What else does streamflow effect? Chemical Processes Nutrient Concentrations Suspended Material Non-point Source Pollution Point Source Pollution

10. Higher Nutrient concentration

11. Higher concentration of TSM with higher streamflow

12. Correll, D.L., 1998. The Role of phosphorus in the eutrophication of receiving waters: A review. Journal of Environmental Quality 27:(2). Pp. 261-266. Falhowski, P.G. and J.A. Raven, 1997. Aquatic Photosynthesis. Blackwell Science, Lt. 2. pp. 310-311. Horton, H.R., L.A. Moron, R.S. Ocha, J.D. Rown, and K.G. Scriagaer, 1996. Principles of Biochemistry: 2 nd edition. Prentice-Hall, Inc. pp. 498-499. Troup, B. N. and Bricker, O. P, 1975. Processes Affecting the Transport of Materials from the Continents to Oceans. Marine Geochemistry in the Coastal Environment: American Chemical Society. Zabawa, Christopher F., 1979. Estuarine Sediments and Sedimentary Processes in Winyah Bay, South Carolina. South Carolina Geological Society: Geologic Notes 23;(2). Pp. 79-117. USGS website- HUCs, NHD, State geography and waterbodies, gaging station and NWIS data (http://www.usgs.gov) EPA website-surf your watershed, river reach file (http://www.epa.gov) South Carolina Department of Natural Resources-orthophotos (http://dnr.state.sc.us) ESRI-data library and help function