نتایج جستجو برای: sediment concentration

تعداد نتایج: 413988  

2014
Alice H. Nelson Paul R. Bierman Jeremy D. Shakun Dylan H. Rood

We use the concentration of in situ Be in quartz isolated from fluvial and morainal sand to trace sediment sources and to determine the relative contribution of glacerized and deglaciated terrain to Greenland’s sediment budget. We sampled along the western, eastern, and southern margins of the Greenland Ice Sheet, and collected sediment sourced from glacerized (n=19) and non-glacerized terrain ...

زینی وند, حسین, حقی زاده, علی , میرزایی, سمیه ,

In this study, the ability of spatially distributed hydrological WetSpa model for simulation of suspended sediment concentration in a daily time step was investigated. Hydro-climate daily data for a period of 7 years including: precipitation, temperature, evaporation, discharge and suspended sediment and three basic basic digital maps of DEM, soil texture and land use, with the cell size of 25 ...

Journal: :journal of agricultural science and technology 2010
h. asadi h. rouhipour h. gh. rafahi h. ghadiri

hairsine and rose (1991) developed a process-based soil erosion model which described the erosion transport of multiparticle sizes in sediment for rain-impacted flow in the absence of entrainment in overland flow. in order to test this model laboratory experiments were carried out in a detachment tray using simulated rainfall. three contrasting soil types were subjected to simulated rainfall at...

ژورنال: علوم آب و خاک 2017
اسدی, حسین, علی‌گلی کلرود, محمد, گرجی, منوچهر,

This study aimed to investigate the dynamic changes of rill erosion and evaluate the ability of Hairsine-Rose model in estimation of sediment concentration. The experiments were carried out at the Soil and Water Conservation Research Station of Tehran University in Kuhin, Qazvin. Four flow rates were tested at three slopes in trapezoidal hand-made rills of 3 m long and 5 cm base width. Outflows...

ژورنال: بوم شناسی آبزیان 2015
Mosavi Nadoshan, Rezvan , Ejlali, Keivan , Fatemi, Seyed Mohamadreza , Mashinchiyan , Ali , Mortezavi, Mohamad Sedigh ,

This is confirmed that bacteria and other living organisms are not able to decompose or excrete the heavy metals, so heavy metals concentrate and accumulate in their tissues and cause toxicity in other organisms in high levels of food chain via biomagnifications and transfer by organisms to the intermediate levels of food chain for instance macrobenthos. Mean concentration of lead was estimated...

Journal: :مرتع و آبخیزداری 0
علی سلاجقه علی فتح آبادی

correct estimation of suspended sediment transported by a river is an important practice in water structure design, environmental problems and water quality issues. conventionally, sediment rating curve used for suspended sediment estimation in rivers. in this method discharge and sediment discharge or concentration related using regression relation that generally is exponential model. respect ...

2002
Hikmet Kerem CIĞIZOĞLU

The methods available in the literature for sediment concentration estimation are complicated and time consuming and necessitate cumbersome parameter estimation procedures. In this study, artificial neural networks (ANNs) are used to forecast and estimate sediment concentration values. The forecasting results obtained using previously observed sediment values were close to the real ones. The se...

Journal: :Coastal Engineering Proceedings 1976

2002
J. M. Grace

The effectiveness of four road turn–out ditch treatments (vegetation, rip–rap, sediment fences, and settling basins) in reducing sediment export to the forest floor was evaluated. These four runoff control methods are commonly prescribed to control forest road runoff and sediments. The study utilized runoff samplers, runoff diversion walls, sediment filter bags, and erosion stakes to evaluate r...

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