I4.1 Development of A New Sediment Flux Model

Abstract

Strong coupling between pelagic and benthic habitats is a fundamental feature of most shallow coastal aquatic ecosystems. However, a flexible, conservative, process-based and computation-efficient ‘sediment flux model’ (SFM) is still lacking although many SFMs of different complexities are available. Here, we present a new SFM that has similar sediment biogeochemical processes to DiToro’s (2001) SFM, but with a simpler structure and fewer parameters. The model is driven by the depositional fluxes of Particulate Organic Matters (POM) from water column. To simulate the remineralization of POM in sediment, a method based on bacteria mediated processes is introduced, which can describe the accumulation and decay of POM. The remineralization processes produce sediment fluxes for NH₄, NO₃, PO₄, Silicate, and SOD. This new SFM is then applied to the Chesapeake Bay where abundant water quality and sediment flux measurements are available. The comparison between model results and sediment flux measurements is good regarding the seasonal cycles at different stations, which validates the model. The new SFM should facilitate the water column ecosystem modeling by providing a flexible framework to include the sediment effects on nutrient budgets.