نتایج جستجو برای: accumulation igeo sediment
تعداد نتایج: 184755 فیلتر نتایج به سال:
[1] On the basis of estimates of sediment accumulation in reservoirs, the impact of 50,000 dams on sediment supply and intertidal wetland response in the Yangtze River catchment is examined. The total storage capacity of reservoirs is 200 10 m, or 22% of the Yangtze annual runoff. The sediment accumulation rate in reservoirs has increased from 0 in 1950 to >850 10 t/yr in 2003. Although sedimen...
The Strickland River is the primary sediment source for the Fly River system, a large tropical river that ranks in the global top 20 for both water and sediment discharge. Over the past decade the Strickland sediment discharge has been gauged at many locations. Comprehensive studies are now underway to study the delivery, transport, and storage of sediment throughout this system. A key question...
The objective of this study was to investigate the concentration and spatial distribution patterns of six potentially toxic heavy metal elements (Mn, Zn, Cr, Pb, Cu and Ni) in bus station dusts in the Xifeng district of Gansu province, NW China. The contents were analyzed for Mn, Zn, Cr, Pb, Cu and Ni by using S8 TIGER Brochures wavelength dispersive X-ray fluorescence spectrometry. Geoaccumula...
Mining is an activity that involves the use of chemicals and results in unsustainable dangerous conditions for miners, their families, community surrounding ecosystem. This study was done to assess metallic contamination soils sediments Bétaré-Oya gold artisanal mine district, East-Cameroon. A total thirty (30) samples exploited soils, control were taken from mining sites Lom, Mbal Mali. The co...
Phosphorus retention (TPacc) was determined in 7 lakes in Ontario, Canada from mass balances and from the direct measurement of phosphorus accumulation in the sediments. Phosphorus retentions determined using the mass balance technique ranged between 20 ± 3.9 and 94 ± 23 mg/m/yr and were slightly lower than those calculated by multiplying sediment total phosphorus (TP) concentrations by sedimen...
Our objectives are to examine sediment PAH distributions in environments representing contrasting depositional regimes within the York River, VA, a sub-estuary of the Chesapeake Bay. Our study utilizes a suite of geochemical tools to quantify sediment processes influencing the distribution of dissolved and solid-phase PAHs. These tools will enable us to quantify particle residence times in surf...
Mercury accumulation and attenuation at a rapidly forming delta with a point source of mining waste.
The Walker Creek intertidal delta of Tomales Bay, California is impacted by a former mercury mine within the watershed. Eleven short sediment cores (10 cm length) collected from the delta found monomethylmercury (MMHg) concentrations ranging from 0.3 to 11.4 ng/g (dry wt.), with lower concentrations occurring at the vegetated marsh and upstream channel locations. Algal mats common to the delta'...
increasing in concentration of heavy metals such as lead, cadmium, nickel, chromium and zinc cause considerable harmful effects on soil and environment. these elements are also hazardous to health of humans and wildlife. petrochemical plants and refineries pollution increase the amount of carcinogenic and tratogenic compounds in environment. the main goal of recent paper is the studying of soil...
Cadmium (Cd) and zinc (Zn) in surface water, sediment, carp, and crab samples collected from upstream and downstream regions of coastal watersheds along the Chinese Northern Bohai and Yellow Seas were analyzed to provide a comprehensive understanding and assessment of their environmental concentrations and bioaccumulations. The results showed that downstream waters contaminated with Zn would ha...
At present there is a poor understanding of changes in rates of erosion over long time periods and in the link between erosion and sediment delivery in Britain. Using a catchment study approach sediment accumulation rates in cores from the three lakes Semer Water, Gormire and Hornsea Mere have been used to reconstruct changes in sediment yield over time periods of up to 10 000 years, and estima...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید