today, water resources stored in reservoirs is one of the basic sources of drinking-water. the elements in the sediments of reservoirs are the most important factors affecting water quality. unlike the primary plan, due to water shortage problems, nowadays, almost all the stored water in the kardeh reservoir is allocated to drinking water. from the other side in the catchment area of this dam a...

Following field observations of increased photosynthesis at increased rates of sediment flushing in sandy sediments, we conducted a series of laboratory experiments to elucidate the mechanism behind these observations. Column experiments in which water was pumped though sand at rates ranging from 0 to 613 L m22 d21 showed that carbon (C) fixation, as measured using carbon-14 (14C) incorporation...

Groundwater plays an important role in coastal regions by delivering freshwater and nutrients to near shore and salt marsh environments. To quantify groundwater flow, salinity, temperature and pressure, sensors were installed in shallow piezometers along a transect behind Blackbeard Island, GA. Located approximately 90 m from the nearest tidal creek, the transect reaches from a back barrier isl...

Linear alkylbenzenes (LABs) were used to assess the fates of hydrophobic organic compounds (HOCs) released to a large urban harbor and the adjoining offshore waters. We found that particulate concentrations of the individual C12 LAB isomers in 1996 summertime surface waters decreased from 1 pM in Boston Harbor to 20-200 fM in coastal Massachusetts and Cape Cod Bays. Levels fell to only a few fM...

Spatial variations in composition of marine microbial communities and its causes have largely been disclosed in studies comprising rather large environmental and spatial differences. In the present study, we explored if a moderate but temporally permanent climatic division within a contiguous arctic shelf seafloor was traceable in the diversity patterns of its bacterial and archaeal communities...

Offshore freshened groundwater (OFG) has been documented in many continental margins worldwide. OFG systems are dynamic, expanding and contracting with falling rise sea-levels. long thought to be an important geomorphic agent margins, either via active discharge at the seafloor, which can erode depressions, or generation of excess pore pressure, deform sediments cause slope failure. It also pro...

Estuaries exhibit a large range in their responses to nitrogen loadings determined in part by characteristics of the driver, such as magnitude and frequency, but also by such intrinsic characteristics as physical/chemical factors (e.g., depth, volume, hypsometry, salinity, turbidity) and biological factors (e.g., nature of ecological communities, trophic interactions). To address the richness o...

Fluvial flows carrying high sediment loads may plunge into reservoirs to form turbidity currents. However, the effects of tributary inflows on reservoir currents have remained poorly understood date. Here a 2D double layer-averaged model is used investigate series laboratory-scale numerical cases. By probing hydro-sediment-morphodynamic processes, we find that location and inflow conditions dis...