Graham Environmental Sustainability Institute

Assessment of the Impact of Watershed Changes on Estuarine Morphology and Aquatic Life

Principal Investigators: Nikolaos Katopodes, Valeriy Ivanov, and Paul Webb.

Student Involved: Seyed Khamsehi, Jongho Kim, April Warnock, Amanda Bednarz, Jennifer Rowe, and Alida Maravi

Units Involved: College of Engineering, School of Natural Resources & Environment, and College of Literature, Sciences, & Arts.

Brief Project Description: The goal of this research project is to develop the methodology for a quantitative assessment of the impact of watershed changes on estuarine and wetland morphology. By linking some key factors of river bed morphology to biota, a quantitative measure of the sustainability of aquatic life will also be developed. Long-term effects of land use practices lead to erosion and sedimentation processes that are responsible for many undesirable changes to aquatic life. Unfortunately, the temporal and spatial scales of this problem are so disparate that a quantitative assessment of the impact of these practices has been previously impossible. We propose a novel approach that can overcome these difficulties by nesting a high resolution estuarine morphology model in a large scale watershed model. Both models are based on sound physical principles and are capable of capturing the true hydrodynamic behavior within their respective domains. The two models are mathematically compatible and have been independently validated, so there is high confidence that their integrated results will provide a unique method for the investigation of long-term changes in aquatic environments.

The integrated watershed-estuarine model will be used to perform a formal sensitivity analysis of estuarine bed morphology to various hydrologic changes at the watershed level. Variations in watershed headwater land use, as well as climate changes, directly affect the local runoff and erosion processes. Over a long period of time these changes also affect the width of beaches, the depth and context of sediments, the cohesion of grain particles and the overall strength of the soil matrix. These hydrodynamic and soil variables will be linked to an aquatic habitat model, resulting in a robust tool for assessing the impact of climatic change and land use practices on specific species. By running simulation scenarios over long-term periods, we will be able to establish quantitative measures for creating sustainable aquatic systems.

Significant Accomplishments (as of January 1, 2009)

External Funding:

Presentations: