abstract for investigating the effect of bed form in alluvial channels on the amount of bed load transport, a set of experiments was carried out in a tilting flume under unsteady flow conditions (hydrograph). the produced hydrographs were in triangular form with a maximum discharge of 30 to 45 lit/s/m. three size of sediment particles were used with equal to 1.5, 2.1 and 3.0mm, clear water with...

[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...

Multiple-Input-Multiple-Output (MIMO) models often assume no correlation between the elements of the channel matrix. This assumption gives an indication on the upper bound of the channel capacity. However, in practice the channel capacity could decrease when the channels are correlated. In this paper, data measured using a 4x4 MIMO test-bed is processed to extract the spatial correlation in an ...

The hydraulics of steep mountain streams differ from lower gradient rivers due to shallow and rough flows, energetic subsurface flow, and macro-scale form drag from immobile boulders and channel and bed forms. Heightened flow resistance and reduced sediment transport rates in steep streams are commonly attributed to macro-scale form drag; however, little work has explored steep river hydrodynam...

[1] A mechanistic model is derived for the rate of fluvial erosion into bedrock by abrasion from uniform size particles that impact the bed during transport in both bed and suspended load. The erosion rate is equated to the product of the impact rate, the mass loss per particle impact, and a bed coverage term. Unlike previous models that consider only bed load, the impact rate is not assumed to...

In the Manning equation the hydraulic radius can be defined as the cross-section dimension of the shape. In pipe flow the bed shear stress is assumed to be uniformly distributed along the wetted perimeter which cannot be true in open channel flow. Hence, three approximation of the true boundary shear-stress distribution are examined and more practical conveyance depth or resistance radius formu...

An important feature of most rivers and canals is their habitats for a rich of aquatic vegetation which is extremely important from an environmental and ecological point of view. These variations in habitat mean that it is rare to find a cross-section of a natural channel which has the same roughness along its perimeter. In these channels, flow conditions lead to a complex flow situation with i...

1. introduction floods are among earth's most common and most destructive natural hazards. floods create geomorphic hazards via changes in sediment transport and channel configuration (e.g. channel width, lateral migration, planform changes, etc). in this context, floodplain zoning and its application in spatial planning is important in non- structural measures in order to reducing flood damage...

abstract morphological river models are designed to provide physical insight into the morphological response and to assist river engineers and managers in the design, operation and maintenance of river systems. here deterministic modeling weak for a dynamic and stochastic of nature river environment. specially, these could not predict the exact shape of the river bed, specially e.g. for braided...