نتایج جستجو برای: rate of sediment load

تعداد نتایج: 21210305  

Journal: Desert 2015

Modeling of stream flow–suspended sediment relationship is one of the most studied topics in hydrology due to itsessential application to water resources management. Recently, artificial intelligence has gained much popularity owing toits application in calibrating the nonlinear relationships inherent in the stream flow–suspended sediment relationship. Thisstudy made us of adaptive neuro-fuzzy ...

Varied flows such as flooding resulting from dam break can happen due to earthquakes, seepage, bombing, overtopping, mistake in design and project performance as well as causing financial damages and human losses. Unsteady flow during flooding events has a high impact on flow field pattern, sediment motion, ecology and also, distribution of contamination in the river. In this study, the impact ...

Journal: :Journal of Hydraulic Research 1976

Journal: :Journal of environmental quality 2005
B E Haggard P A Moore P B Delaune

Phosphorus inputs into reservoirs include external sources from the watershed and internal sources from the reservoir bottom sediments. This study quantified sediment P flux in Lake Eucha, northeastern Oklahoma, USA, and evaluated the effectiveness of chemical treatment to reduce sediment P flux. Six intact sediment-water columns were collected from three sites in Lake Eucha near the reservoir ...

Journal: :Science 2005
James P M Syvitski Charles J Vörösmarty Albert J Kettner Pamela Green

Here we provide global estimates of the seasonal flux of sediment, on a river-by-river basis, under modern and prehuman conditions. Humans have simultaneously increased the sediment transport by global rivers through soil erosion (by 2.3 +/- 0.6 billion metric tons per year), yet reduced the flux of sediment reaching the world's coasts (by 1.4 +/- 0.3 billion metric tons per year) because of re...

A. Ardeshir, F. Bahadori and A. Tahershamsi,

In this paper, development of a semi-two- dimensional mathematical model called SDAR is introduced. The model is composed of two principal modules of hydraulics and sediment transport. The newly developed SDAR model has a number of capabilities including determination of sediment transport rate, aggradation - degradation&#10calculation, longitudinal profile and lateral cross–sectional variation...

2009
Joel P. L. Johnson Kelin X. Whipple Leonard S. Sklar Thomas C. Hanks

[1] Field data from channels in the Henry Mountains of Utah demonstrate that abundant coarse sediment can inhibit fluvial incision into bedrock by armoring channel beds (the cover effect). We compare several small channels that share tributary junctions and have incised into the same sedimentary bedrock unit (Navajo Sandstone) but contain differing amounts of coarse diorite clasts owing to the ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان همدان - دانشکده ادبیات و علوم انسانی 1390

abstract this study is an attempt to determine the effect of nano- technology education on science lesson for fifth grade in primary school in the city of kermanshah. this research is experimental and is conducted in the from of pre-test and post- test for the control group. an achievement test was administered to determine the rate of learning in the students. the research is an applied one. ...

2002
PAUL D. KOMAR

Depending on their grain sizes (settling velocities), sed iments are t ransported in rivers as bed load, in suspens ion , or as wash load. The coarsest material rolls or bounces along the bot tom as bed load whereas finer material is placed into suspens ion by the water turbulence. The finest sed iments are t ranspor ted as wash load. evenly distr ibuted through the water depth and effectively ...

Journal: :تحقیقات نظام سلامت 0
حبیب اله دهقان گروه مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشکده بهداشت دانشگاه علوم پزشکی اصفهان، اصفهان، ایران سیف اله غریب کارشناسی ارشد مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشکده بهداشت دانشگاه علوم پزشکی اصفهان، اصفهان، ایران حسینعلی یوسفی ریزی گروه مهندسی بهداشت حرفه ای، دانشکده بهداشت، دانشکده بهداشت دانشگاه علوم پزشکی اصفهان، اصفهان، ایران

background: noise is one of the annoying agents in the environment and it is harmful agent in workplaces that its occurrence with work load, there are in many workstations. the aim of this study was to determine the combined effects of exposure to noise and work load on heart rate changes. methods: this cross-sectional study performed on 14 male students into climatic chamber in 2011.the mean ±...

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