Morphology of the Kosi megafan channels

Gaurav, Kumar; Métivier, François; Devauchelle, Olivier; Sinha, Rajiv; Chauvet, Hugo; Houssais, Morgane; Bouquerel, Hélène

doi:10.5194/esurf-3-321-2015

Cited by 31 publications

(82 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mean surface velocity was measured using floats. The average velocity was obtained from the surface velocity using a correction factor of 0.6 (Sanders, 1998;Gaurav et al, 2015). The discharge was obtained by the product of the average velocity with the wetted area.…”

Section: Methodsmentioning

confidence: 99%

“…We thus need to detrend our data set with respect to water discharge, based on analytical regime equations. Following Gaurav et al (2015), we propose to use the threshold theory to do so.…”

Section: Detrendingmentioning

confidence: 99%

“…Most authors treat the channel as a whole by defining lumped quantities, such as the total channel width or the average water depth (Métivier and Barrier, 2012). Conversely, few studies focus on the morphology of braided and meandering channels at the level of individual threads (Church and Gilbert, 1975;Mosley, 1983;Ashmore, 2013;Gaurav et al, 2015). In sand-bed rivers, the geometry of braided threads appears to be indistinguishable from that of meandering ones.…”

mentioning

confidence: 99%

“…After comparison with other data sets from the literature, we compare the morphology of braided and meandering threads in our data set. Finally, we rescale our measurements based on the threshold theory to generate and analyze a single statistical ensemble from rivers highly dispersed in size (Glover and Florey, 1951;Henderson, 1963;Seizilles et al, 2013;Gaurav et al, 2015).…”

mentioning

confidence: 99%

See 3 more Smart Citations

Geometry of meandering and braided gravel-bed threads from the Bayanbulak Grassland, Tianshan, P. R. China

Métivier¹,

Devauchelle

Chauvet

et al. 2016

Earth Surf. Dynam.

View full text Add to dashboard Cite

Abstract. The Bayanbulak Grassland, Tianshan, P. R. China, is located in an intramontane sedimentary basin where meandering and braided gravel-bed rivers coexist under the same climatic and geological settings. We report and compare measurements of the discharge, width, depth, slope and grain size of individual threads from these braided and meandering rivers. Both types of threads share statistically indistinguishable regime relations. Their depths and slopes compare well with the threshold theory, but they are wider than predicted by this theory. These findings are reminiscent of previous observations from similar gravel-bed rivers. Using the scaling laws of the threshold theory, we detrend our data with respect to discharge to produce a homogeneous statistical ensemble of width, depth and slope measurements. The statistical distributions of these dimensionless quantities are similar for braided and meandering threads. This suggests that a braided river is a collection of intertwined threads, which individually resemble those of meandering rivers. Given the environmental conditions in Bayanbulak, we furthermore hypothesize that bedload transport causes the threads to be wider than predicted by the threshold theory.

show abstract

Section: Methodsmentioning

confidence: 99%

“…We thus need to detrend our data set with respect to water discharge, based on analytical regime equations. Following Gaurav et al (2015), we propose to use the threshold theory to do so.…”

Section: Detrendingmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Geometry of meandering and braided gravel-bed threads from the Bayanbulak Grassland, Tianshan, P. R. China

Métivier¹,

Devauchelle

Chauvet

et al. 2016

Earth Surf. Dynam.

View full text Add to dashboard Cite

show abstract

“…As a result, the width, depth, and slope of the channel are set by its water discharge. In particular, according to the simplest version of this theory (Devauchelle et al, 2011;Gaurav et al, 2015;Métivier et al, 2017), the equilibrium slope reads…”

Section: Mass Balancementioning

confidence: 99%

Self-similar growth of a bimodal laboratory fan

et al. 2017

View full text Add to dashboard Cite

Abstract.Using laboratory experiments, we investigate the growth of an alluvial fan fed with two distinct granular materials. Throughout the growth of the fan, its surface maintains a radial segregation, with the less mobile sediment concentrated near the apex. Scanning the fan surface with a laser, we find that the transition between the proximal and distal deposits coincides with a distinct slope break. A radial cross section reveals that the stratigraphy records the signal of this segregation. To interpret these observations, we conceptualize the fan as a radially symmetric structure that maintains its geometry as it grows. When combined with slope measurements, this model proves consistent with the sediment mass balance and successfully predicts the slope of the proximal-distal transition as preserved in the fan stratigraphy. While the threshold-channel theory provides an order-of-magnitude estimate of the fan slopes, driven by the relatively high sediment discharge in our experimental system, the actual observed slopes are 3-5 times higher than those predicted by this theory.

show abstract