2013 Undergrad Research Day

River Influence on Marine Water Quality and Coral Reef Condition, Southwest Jamaica

Aaron T. Pavlowsky
Geography, Geology, and Planning
Faculty Advisor: Dr. Judith L. Meyer

Marine fisheries and coral reefs in Jamaica have degraded over the past three decades due to over-exploitation, coastal development, and river pollution by nutrients and sediment. This study evaluates the influence of river discharge and pollution loads on coastal water quality along the southwest coast of Jamaica. Water and sediment quality were measured along three offshore transects associated with inputs from the Bluefields and Sweet Rivers in the Bluefields Bay Fish Sanctuary, the Black River Bay, and Galleon Beach Fish Sanctuary. River mouth mixing zones were identified with temperature and salinity profiles. Nutrient levels in the bay were evaluated using phosphorus concentrations in the water column and fine-grained bottom sediment. In addition, sediment metals were also evaluated. Sampling points were located with a global positioning system and mapped with ArcGIS software. Under low flow river conditions, freshwater influence usually extended <500 m offshore in Bluefields Bay. However, in the Black River Bay, brackish water extended a few kilometers offshore. The highest nutrient concentrations were found in bays fed by larger rivers draining urban and agriculture land use. Coral reef conditions declined with excess sediment deposition and higher nutrient levels in the Black River Bay.

Seasonal Variations in Rainfall-discharge Relationships for Missouri Watersheds

Joshua D. Elson
Department of Geography, Geology, & Planning
Faculty Advisor: Dr. Bob Pavlowsky

Watershed hydrology exerts major influence on the ecological and geomorphic processes within a river. In this study, long-term monthly discharge trends are evaluated to investigate changes in flow conditions related to seasonal weather patterns, climate change, and land use conditions. Hydrologic records were generated from historical records from eight USGS surface water monitoring stations in different Missouri river basins. Monthly discharge data was divided into the four seasons to investigation seasonal variation. Generally, stations share two distinct trend lines found within the seasons that can be explained by seasonal vegetation coverage. Summer and fall share a trend line that have lower discharge values that are explained by an increase in evapotranspiration due to maximum vegetation cover and air temperature. Spring and winter share similar trend lines with relatively higher discharge totals per unit depth of precipitation which indicates less water loss to evapotranspiration due to cooler temperatures, less foliage interception, and lower rates of soil water uptake. Hydrological variations of Missouri basins are also impacted by topographic relief, latitude, urbanization, deforestation and climate change. Winter has recently seen less variability, which might be explained by warmer winters seen over the last couple decades.

Effects of Slope Angle and Flow Time on Fluvial Geomorphology Using a Stream Table

Michael Jahnke
Geography, Geology, and Planning
Faculty Advisor: Dr. Bob Pavlowsky

Stream formation is a complex process, but when broken down into simpler studies, can prove powerful to understanding the geomorphic and hydrologic processes involved in rivers and related landform development. Using a stream table, several hypotheses regarding fluvial geomorphology were studied: what is the chronology of landform development and how does slope angle influence the degree and speed of landform development. In this study, trials were run at three different slope angles, 2 degrees, 5 degrees, and 10 degrees, allowing water to flow for 5-minute intervals. The resultant stream forms were photographed and analyzed to show that the sequence of landform development is the same, regardless of slope. Flume results also showed that as the slope of the stream table increases, fluvial landform development occurs more rapidly. A final outcome is that as time increases, more pronounced landforms form due to prolonged erosional work. From these results, a chronologic sequence of stream development can be created, allowing greater understanding of fluvial processes.

Water Temperature Variations over Multiple Scales in the James River, Sw Missouri Power Station

Sara Cheek
Geography, Geology, and Planning
Faculty Advisor: Dr. Robert Pavlowsky

Thermal pollution is a consequence of utilizing a water body as cooling water discharge for a power plant. Heated water released by power plants puts aquatic organisms at risk due to reduced dissolved oxygen levels. In 2002, approximately 200 fish were found dead near the dam at Lake Springfield that serves as cooling water for the James River Power Station. This study evaluates influence of thermal releases to the main stem of the James River within the context of daily, seasonal, and annual temperature variability. Temperature records were evaluated from ambient water quality stations, TMDL, and a study by the authors that monitored water temperature changes above and below a coal-fired power plant discharge point. Water temperature data was collected with a Horiba U-22XD multi-parameter probe weekly from October to December 2012. Average temperatures increased by 7 oC in the James River from 13.8 oC above the plant to 20.8 oC below the plant outfall. Long-term and current temperature and dissolved oxygen data were analyzed to examine if levels fell below Missouri guidelines of 5.0 mg/L.