نتایج جستجو برای: sediment

تعداد نتایج: 36882  

2002
Andrew G. Warne Robert H. Meade William A. White Edgar H. Guevara James Gibeaut Rebecca C. Smyth Andres Aslan Thomas Tremblay

Interacting river discharge, tidal oscillation, and tropical rainfall across the 22,000 km Orinoco delta plain support diverse fresh and brackish water ecosystems. To develop environmental baseline information for this largely unpopulated region, we evaluate major coastal plain, shallow marine, and river systems of northeastern South America, which serves to identify principal sources and contr...

2013
F. GILBERT

The in vitro fate of the saturated hydrocarbon fraction (SF) of Arabian Light crude oil has been studied in PVC cores filled with a coastal marine sediment defaunated by sieving. Experiments were conducted in absence or presence of polychaetes Nereis diversicolor. The luminophore tracer technique was used to quantify the mixing of sediment by worms. Presence of crude oil reduced the building of...

Journal: :Environmental toxicology and chemistry 2002
Heather A Morrison D Michael Whittle G Douglas Haffner

A food web bioaccumulation model was used to compare transport and fate of polychorinated biphenyls (PCB) congeners in three food webs in the Laurentian Great Lakes of North America. The model was used to quantify the contribution of sediment-derived and freely dissolved PCBs to the body burden of aquatic biota. In eastern Lake Erie (OH, USA), almost 100% of the chemical body burden of biota or...

Journal: :Environmental toxicology and chemistry 2001
M T Togna J Kazumi S Apitz V Kirtay L Y Young

Mineralization of a readily biodegradable aromatic compound (benzoate) by intrinsic microorganisms in the anoxic sediment was used to quantify the inhibitory effect of heavily contaminated sediment from the Arthur Kill estuary (NY/NJ Harbor system, USA) on the anaerobic metabolism by naturally present bacterial populations. In anoxic microcosms, the effect of varying ratios of contaminated sedi...

Journal: :The Science of the total environment 2016
A B Gray G B Pasternack E B Watson M A Goñi J A Hatten J A Warrick

This study is an investigation into the roles of wildfire and changing agricultural practices in controlling the inter-decadal scale trends of suspended sediment production from semi-arid mountainous rivers. In the test case, a decreasing trend in suspended sediment concentrations was found in the lower Salinas River, California between 1967 and 2011. Event to decadal scale patterns in sediment...

2017
Jose Ramon B. Cantalice Luis da Silva Souza Yuri Jacques Agra Bezerra Silva Sergio M.S. Guerra Alex Mauricio Araújo Douglas Monteiro Cavalcante Cinthia Maria Cordeiro Atanazio Cruz Silva

Sediment transport relates to suspended sediment and bedload. The suspended sedi‐ ment plays the most important role on the land-ocen sediment flux. On the other hand, the bedload should be considered in order to assess the impacts of dams on sediment transport and sediment yield. Recent effects of dam construction have been widely reported. The sediment load has been reduced by more than 75% f...

Journal: :تحقیقات مهندسی کشاورزی 0
جمال محمد ولی سامانی دانشیار گروه سازه های آبی دانشگاه تربیت مدرس رضا فرشاد دانشجوی کارشناسی ارشد سازه های آبی دانشگاه تربیت مدرس

pure rockfill dams have been found specific attention in watershed management and flood control, recently. in addition to hydraulic specific features, one of the important advantages of these structures is their consistency with nature and environment. normally, floods are accompanied with high sediment loads which may enter the body of dam. when flow through dam body governed by hydraulic grad...

Journal: :ecopersia 2012
asghar kouhpeima sadat feiznia

today fingerprinting techniques are increasingly adopted as an alternative and more direct and reliable means of assembling sediment source information. one of the principal assumptions of sediment fingerprinting is that potential catchment sediment sources can be distinguished on the basis of their physical, geochemical and biological properties or fingerprint properties. however, while the so...

Mohammad JavadZeynali, Omolbani Mohammadrezapour,

By far, different models for determining the relationship between the flow rate  and amount of precipitation have been developed. many models are based on regression models with limited assumptions. one of the most common methods for estimating  sediment of rivers is sediment rating curve. for better estimation of the amount of sediment based of sediment curve  rating equation, it is possible t...

2014
Robert L. Stewart Cindy K. Harnett

A light attenuation sensor system (LASS) for measurements in waters is described in this paper. The LASS records irradiance at multiple levels in the water column to provide a measure of the diffuse light attenuation coefficient which is strongly affected by suspended sediment. Dimensional analysis and geometric optical theory are used to relate the irradiance attenuation to sediment properties...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید