The Gorgan Bay is an important ecosystem receiving discharge from their tributaries. In this study, concentration of Pb, Zn, Ni, Fe, Al, Cu and As was seasonally determined at 22 sampling points during 2012-2013.Sediment samples were collected using a Van Veen grab. The levels of heavy metals were determined by ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) and AAS (Atomic Ab...

This paper discusses the development and application of a spatial tool for erosion modeling named Spatial Decision Assistance of Watershed Sedimentation (SDAS). SDAS computes export (yield) of sediment from watershed as product of erosion rate and sediment delivery ratio (SDR). The erosion rate is calculated for each raster grid according to a digital elevation model, soil, rain fall depth, and...

Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses ...

This study deals with the transport behavior of the coarse-sediment at Masudagawa flood mitigation dam (FMD), Japan. Radio frequency identification system (RFID) was used to trace the displacement of the IC tagged particles following major flood events since June 2011. Through this, the relationship between recovery rate of the tagged particles and distribution of shear stress over the FMD bed ...

The scientific objective of this research is to evaluate various inversion algorithms and to assess conditions of their applicability for several specific types of heterogeneous rough sea beds. Another goal is to provide recommendations, first, on the choice of optimal parameters for acoustic measurements and, secondly, on accompanying environmental measurements of sediment heterogeneity. Also,...

Our long term goal is to develop a tested model of optical properties in the surf zone and adjacent nearshore ocean, including the influence of suspended sediment, bubble population and surface foam, to assess how optical properties are related to short term events such as individual breaking wave crests, and to determine how wave-driven surf zone circulation influences spatial distribution of ...

A quantitative understanding of both natural and anthropogenic sediment sources is needed to accurately assess and predict the potentially adverse effects of land development on aquatic ecosystems. The main objective of this study was to quantify sediment production and delivery rates in a dry tropical environment on the island of St. John in the eastern Caribbean. One to three years of measure...

In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites wit...

In surface sediments, metal mobility is controlled by the recruitment and turn-over of organic matter whereas sulphide is thought to control the concentration of metals in sediment pore water by removing them from the solution. DGT is a dynamic probe that measures the kinetically available fraction of metals or sulphide. DGT uses a credit card size probe inserted into the sediment that provides...