Natural bedrock rivers flow in self-formed channels and form diverse erosional morphologies. The parameters that collectively define channel morphology (e.g. width, slope, bed roughness, bedrock exposure, sediment size distribution) all influence river incision rates and dynamically adjust in poorly understood ways to imposed fluid and sediment fluxes. To explore the mechanics of river incision...

■ Abstract Measurements of cosmogenic nuclides, predominately 10Be, allow new insights into the ways in which and the rates at which sediment is generated, transported, and deposited over timescales ranging from 103 to 106 years. Samples from rock exposures are used to estimate erosion rates at points on the landscape, whereas samples of fluvial sediment provide estimates of basin-scale rates o...

The use of a model based on Langmuir's isotherm to evaluate the metal associated with separate geochemical phases of a sediment is proposed and its validity tested with sediments of certified composition. The model takes into account a standard procedure for a certified reference material (CRM601), which defines, experimentally, a set of sequential extractions that divide the sediment into four...

Sediment of different size are transported in rivers under the action of flow. The first and still most popular sediment continuity model able to deal with mixed sediment is the so-called active layer model proposed by Hirano (1971, 1972). In this paper, we consider the one-dimensional hydromorphodynamic model given by the Saint-Venant equations for free-surface flow coupled with the active lay...

[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 ...

A study is presented on the distribution of thorium and radium isotopes in sediments, suspended matter and water collected along Jucar river (East of Spain), using low-level CC-spectrometry. The first aim of this work is to study the thorium and radium activity in water, sediment and suspended matter and their dependence on pH, temperature, conductivity and sediment sizes along Jucar river. The...