Net effect of rainfall activity on salt-marsh sediment distribution

It has been established that increased suspended sediment concentrations in tidal waters adjacent to salt-marshes occur during periods following heavy rainfall events. In this work, we present experimental data for concentration and sediment flux measurements during periods of natural moderate rainfall events from a microtidal, alochthonous salt-marsh system (North Inlet, South Carolina, USA). The results indicate that rainfall events, although responsible for increasing sediment concentration levels, do not alter the sediment flux of the system. In our results, the sediment mobilized by the rain was re-introduced to the system. Further, using the geochemical signatures of suspended particles from the same location, we found that the sediment mobilized by rainfall events is the same as the sediment present in the tidal creeks, suggesting that rainfall mobilizes only recently deposited, non-consolidated sediment and does not erode the substrate of the marsh surface. (C) 2004 Elsevier B.V. All rights reserved.