A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic compo...

A Winogradsky column is a clear glass or plastic column filled with enriched sediment. Over time, microbial communities in the sediment grow in a stratified ecosystem with an oxic top layer and anoxic sub-surface layers. Winogradsky columns have been used extensively to demonstrate microbial nutrient cycling and metabolic diversity in undergraduate microbiology labs. In this study, we used high...

The Annualized Agricultural Non-Point Source (AnnAGNPS) model has been developed to quantify watershed response to agricultural management practices. The objective of this study was to identify critical areas where conservation practices could be implemented and to predict their impact on Beasley Lake water quality in the Mississippi Delta using AnnAGNPS. Model evaluation was first performed by...

The present study investigated cross-media transport between both the sediment and the water column and between the water column and the atmosphere, to understand the role of each compartment as a source or a sink of polycyclic aromatic hydrocarbons (PAH) in southern California, USA, coastal waters. Concentrations of PAH were measured in the atmosphere, water column, and sediment at four water-...

Published data are used to construct an approximate sediment budget for the 1.656 × 10 km catchment of the Ganga and Brahmaputra rivers. From these data, it has not been possible to identify the major sources of sediment. Recently published Nd/Sr tracer results suggest that the High Himalaya is the main source of sediment, providing for the first time a focus for more detailed research on the r...

Management of bottomland hardwood sites requires adequate access to support forest operations. A study conducted in a bottomland forest in central Georgia has evaluated the effect of forest road design on sediment movement and water quality. Five years of measurement indicate that a conventional crowned road design is a net sir& for sediment, primarily due to settling in ditches. An alternative...

Human activities within a watershed, such as agriculture, urbanization, and dam building, may affect the sediment yield from the watershed. Because the equilibrium geomorphic form of an estuary is dependent in part on the sediment supply from the watershed, anthropogenic activities within the watershed have the potential to affect estuary geomorphology. The Sacramento River drains the northern ...