Chang, M. U. of Maryland Ctr. for Envir. Science, Horn Point Lab., chang@hpl.umces.edu
Sanford, L. U. of Maryland Ctr. for Envir. Science, Horn Point Lab., lsanford@hpl.umces.edu

 
MODELING THE INFLUENCES OF RESUSPENSION AND DEPOSITION ON EARLY DIAGENESIS OF PHOSPHORUS
 
In order to better understand the effects of resuspension on phosphorus cycling, we have developed a 1-D numerical time and depth dependent model that includes advection, diffusion, first order particulate organic phosphorus (POP) degradation and equilibrium sorption for dissolved inorganic phosphorus (DIP). The model simulates interactions between a water column, a resuspendable floc layer, and the underlying sediments through a 30 day period with a 12-hour resuspension event at day 5. We have used the model to explore the responses of both relatively polluted and relatively clean sediments to different input loadings and hydrodynamic forcings. Our results indicate that resuspension at the sediment-water interface: 1)increases DIP concentrations in the water column; 2)affects porewater fluxes by increasing mass transport, but decreasing the concentration difference between the water column and sediments; 3)decreases accumulation of inorganic phosphorus and speeds up recycling rates; 4)allows greater diagenesis to take place. We have also used the model to explore the effects of two identical resuspension events with different intervals between events. The results show an increasing resuspension response with longer inter-event intervals. Sensitivity analyses using a Monte Carlo Simulation Technique will also be presented.
 
Day: Thursday, Feb. 4
Time: 12:15 - 12:30pm
Location: Eldorado Hotel
 
Code: SS52TH1215E