RIVER-BED DEGRADATION WITH ARMORING
نویسندگان
چکیده
منابع مشابه
Granular bed consolidation, creep and armoring under subcritical fluid flow
We show that a freshly sedimented bed composed of spherical grains settles and creeps forward over extended periods under an applied hydrodynamic shear stress τ∗, which is below the critical value τ∗ c for bedload transport. The rearrangements are found to last at least over millions of times the sedimentation time scale of a grain in the fluid. Compaction occurs throughout the bed, but creep i...
متن کاملModeling a dynamically varying mixed sediment bed with erosion, deposition, bioturbation, consolidation, and armoring
Erosion and deposition of bottom sediments reflect a continual, dynamic adjustment between the fluid forces applied to a sediment bed and the condition of the bed itself. Erosion of fine and mixed sediment beds depends on their composition, their vertical structure, their disturbance/recovery history, and the biota that inhabit them. This paper presents a new onedimensional (1D), multi-layer se...
متن کاملDynamic transport capacity in gravel-bed river systems
Sediment transport capacity mediates the transfer and storage of bed material between alluvial reservoirs in a drainage system. At intermediate time scales (100-102 yr) corresponding to the evolution of sediment pulses, conditions governing bed-material transport capacity under the hydrologic regime respond to variations in storage and sediment flux as pulses extend, overlap, and attenuate thro...
متن کاملsimulation of armouring process in river bed
abstract the concept of armouring is used to discuss the coarse surface layer in rivers. selective erosion in an alluvial channel reach for which there is no upstream sediment supply can lead to formation of a layer coarser than the under laying material. this phenomenon inhibits sediment transport from the reach.numerical modeling of armouring river bed, provides an approach to simulation of t...
متن کاملDo gravel bed river size distributions record channel network structure?
[1] Bed load sediment particles supplied to channels by hillslopes are reduced in size by abrasion during downstream transport. The branching structure of the channel network creates a distribution of downstream travel distances to a given reach of river and thus may strongly influence the grain size distribution of the long-term bed load flux through that reach. Here we investigate this hypoth...
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ژورنال
عنوان ژورنال: Proceedings of the Japan Society of Civil Engineers
سال: 1971
ISSN: 1884-4936,0385-5392
DOI: 10.2208/jscej1969.1971.195_55