نتایج جستجو برای: stream sediment

تعداد نتایج: 93248  

2011
Frank J. Triska F. J. Triska

Biogeochemical processes in rivers are controlled by biological, chemical, geomorphic and hydrologic interactions. These interactions produce variable redox environments wherein microorganisms derive energy and synthesize tissue using oxidation-reduction reactions associated with several elements including C, N, P, S, and to a lesser extent Fe and Mn. Biogeochemistry of river water and surface ...

2003
R. W. McDowell A. N. Sharpley G. Folmar

Phosphorus (P) export from agricultural catchments can accelerate freshwater eutrophication. Landscape-based remedial measures can reduce edge-of-field P losses. However, stream channel hydraulics and fluvial sediment properties can modify the forms and amounts of P exported by the time it reaches the catchment outlet. This study examines if land use, fluvial sediment properties, and storm flow...

2001
Pete Bettinger

ABSTRACT We developed a scheduling model (LMSCHED) that incorporates stream sediment and stream temperature goals into a forest planning process, allowing one to both evaluate the levels of these measures of aquatic habitat, and to set constraints regarding their upper limit. The scheduling model uses tabu search to identify feasible forest plans with respect to goals and constraints that are s...

Journal: :Water research 2010
A Garzio-Hadzick D R Shelton R L Hill Y A Pachepsky A K Guber R Rowland

Escherichia coli bacteria are commonly used as indicator organisms to designate of impaired surface waters and to guide the design of management practices to prevent fecal contamination of water. Stream sediments are known to serve as a reservoir and potential source of fecal bacteria (E. coli) for stream water. In agricultural watersheds, substantial numbers of E. coli may reach surface waters...

Journal: :نشریه مهندسی عمران و نقشه برداری 0
احمد طاهرشمسی دانشگاه صنعتی امیرکبیر فرهاد ایمان شعار دانشگاه صنعتی امیرکبیر

in this paper, river regime equations through developing of unit stream power equation and based on data of sistan and karaj rivers were derived. at the first step, methods and out-comes of former researchers are classified. on the next step, based on dimensional analysis, unit stream power as a function of river flow parameters including suspended sediment load and specific gravity of particle...

رحیمی, بهنام, مظاهری, سید احمد, کریم‌پور, محمد حسن, قادری, مجید , قوی, جمال ,

Tarikdarreh prospect area is situated in northeastern Iran at the boundary between Central Iran and Kopet-Dagh structural zones. Torbat-e-Jam granitoid intrusion of Triassic age is the main magmatic display in the district. These plutonic rocks with NW-SE trending intruded Miankouhi Formation (Upper Triassic) consisting of coaly shale, siltstone and sandstone converting those to hornfels for te...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Clifford S Riebe Leonard S Sklar Claire E Lukens David L Shuster

Weathering on mountain slopes converts rock to sediment that erodes into channels and thus provides streams with tools for incision into bedrock. Both the size and flux of sediment from slopes can influence channel incision, making sediment production and erosion central to the interplay of climate and tectonics in landscape evolution. Although erosion rates are commonly measured using cosmogen...

2004
CHRISTOPHER T. SOLOMON ALEXANDER S. FLECKER BRAD W. TAYLOR

In Neotropical streams, benthic sediment affects community structure and may impose energetic costs for some species yet to be a resource for others. This study tested the hypothesis that removal of benthic sediment through ingestion by Rana palmipes (Ranidae), a detritivorous tadpole, facilitated the growth of Ancistrus triradiatus (Loricariidae), an algivorous armored catfish. We hypothesized...

1985
S. Grauso

Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract In the present work, an application of statistical regression relationships utilising ge-omorphic parameters is attempted in a spatially distributed mode, in order to predict the amount of river sediment supply at varying sections of the d...

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