The contributions of F. Douglas Shields Jr and Charles M Cooper to this article were prepared as part of their duties as United States Federal Government Employees.
Numerical simulation of sediment-associated water quality processes for a Mississippi delta lake
Article first published online: 10 AUG 2009
Copyright © 2009 John Wiley & Sons, Ltd.
Special Issue: The National Sedimentation Laboratory: 50 years of soil and water research in a changing agricultural environment
Volume 2, Issue 3, pages 350–359, September 2009
How to Cite
Chao, X., Jia, Y., Douglas Shields, F., Wang, S. S. Y. and Cooper, C. M. (2009), Numerical simulation of sediment-associated water quality processes for a Mississippi delta lake. Ecohydrol., 2: 350–359. doi: 10.1002/eco.72
- Issue published online: 25 SEP 2009
- Article first published online: 10 AUG 2009
- Manuscript Accepted: 19 MAY 2009
- Manuscript Received: 5 JAN 2009
- USDA-ARS National Sediment Laboratory (NSL)
- water quality;
- numerical model;
- bed release
Three major sediment-associated processes were presented to describe the effects of sediment on the water quality processes, including the effect of sediment on the light intensity for the growth of phytoplankton (PHYTO), the adsorption–desorption of nutrients by sediment and the release of nutrients from the bed sediment layer. A formula was generated from field measurements to calculate the light attenuation coefficient by considering the effects of concentrations of chlorophyll and suspended sediment (SS). The concentrations of adsorbed and dissolved nutrients because of adsorption–desorption were calculated using two formulas that were derived based on the Langmuir Equation. The release rates of nutrients from the bed sediment were calculated by considering the effects of the concentration gradient across the water-sediment interface, pH, temperature and dissolved oxygen (DO) concentration. Model algorithms describing the adsorption and desorption of nutrients from sediment particles as well as the release of nutrients from bed sediment were tested using experimental data. These sediment-associated water quality processes were included in a three-dimensional (3D) water quality model, CCHE3D_WQ, developed by the National Center for Computational Hydroscience and Engineering (NCCHE), to simulate the concentrations of PHYTO and nutrients in a shallow Mississippi Delta lake with special emphasis on sediment-related processes. The simulated concentration of PHYTO (as chlorophyll) and nutrients were generally in good agreement with field observations. This study shows that there are strong interactions between sediment-associated processes and water quality constituents. Copyright © 2009 John Wiley & Sons, Ltd.