نتایج جستجو برای: sediment

تعداد نتایج: 36882  

2007
E. M. Yager J. W. Kirchner W. E. Dietrich

[1] Steep, rough channels occupy a large fraction of the total channel length in mountainous regions. Most sediment mobilized on hillslopes must pass through these streams before reaching lower-gradient channels. Steep channels have wide grain size distributions that are composed of finer, more mobile sediment and large, rarely mobile grains. The large grains can bear a significant portion of t...

1993
Sue Hilton Thomas E. Lisle

USDA Forest Service Res. Note PSW-RN-414-WEB. 1993. E xperienced hydrologists and geomorphologists can estimate the relative mobility of a streambed by looking at indicators of bedload transport, such as the freshness of bed-surface material. Another such indicator is the amount of fine sediment in pools. Pools in gravelbed streams commonly contain deposits of fine sediment (mostly sand and gra...

Journal: :Water science and technology : a journal of the International Association on Water Pollution Research 2013
Ying-Heng Fei Xiao-Yan Li

The effect of decomposition and diagenesis of sediment organic matter (SOM) on the adsorption of emerging pollutants by the sediment has been seldom addressed. In the present experimental study, artificial sediment was incubated to simulate the natural organic diagenesis process and hence investigate the influence of organic diagenesis on the adsorption of tetracyclines (TCs) by marine sediment...

2008
K. R. Beg

The objective of this study was the sediment quality assessment of Ganga River at Kanpur city where effluents from tannery industries are discharged. Sediment samples from upstream and downstream area were collected and analyzed for trace metals and toxicity bioassay. Among various trace metals examined Cr in downstream sediment was 30-fold higher than in upstream sediment and its concentration...

2001
Tim Lauck Roland Lamberson Thomas E. Lisle

Salmonid embryos depend on the adequate flow of oxygenated water to survive and interstitial passageways to emerge from the gravel bed. Spawning gravels are initially cleaned by the spawning female, but sediment transported during subsequent high-runoff events can nfiltrate the porous substrate. In many gravel-bed channels used for spawning, most of the infiltrating sediment consists of sand an...

Fatemeh Shokrian, K. Shahedi,

Estimate of sediment load is required in a wide spectrum of water resources engineering problems. The nonlinear nature of suspended sediment load series necessitates the utilization of nonlinear methods to simulate the suspended sediment load. In this study Artificial Neural Networks (ANNs) are employed to estimate daily suspended sediment load. Two different ANN algorithms, Multi Layer Perce...

2005
W. E. Dietrich P. A. Nelson E. Yager J. G. Venditti

Bed surface particle size patchiness may play a central role in bedload and morphologic response to changes in sediment supply in gravel-bed rivers. Here we test a 1-D model (from Parker ebook) of bedload transport, surface grain size, and channel profile with two previously published flume studies that documented bed surface response, and specifically patch development, to reduced sediment sup...

2002
XU JIONGXIN

The runoff and sediment of large rivers usually come from different source areas, which make different contributions to the sediment flux into the sea. This has been studied with the example of the Yellow River in China, whose suspended sediment flux into the Bohai Sea accounts for 19.4% of the world total. The drainage basin of this river can be divided into four major water and sediment sourc...

2011
Hari Prasad Neopane Ole Gunnar Dahlhaug Michel Cervantes

Sediment erosion not only reduces efficiency and life of hydropower turbines but also causes problems in operation and maintenance. Several factors are responsible for this erosion in hydro turbine components. This paper presents the sediment erosion types in hydraulic turbines and their components based upon an extensive literature review and the field observation at Cahua hydropower plant, Pe...

Journal: :Applied and environmental microbiology 1987
P H Pritchard E J O'Neill C M Spain D G Ahearn

Shake-flask and microcosm studies were conducted to determine the fate of para-chlorophenol (p-CP) in water and sediment systems and the role of sediment and nonsediment surfaces in the biodegradation process. Biodegradation of p-CP in estuarine water samples in shake flasks was slow over incubation periods of 300 h. The addition of detrital sediment resulted in immediate and rapid degradation ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید