Morphodynamics of the erosional phase of crevasse-splay evolution and implications for river sediment diversion function

Yuill, Brendan; Khadka, Ashok K.; Pereira, J. F.; Allison, Mead A.; Meselhe, E. A.

doi:10.1016/j.geomorph.2016.02.005

Cited by 70 publications

(40 citation statements)

References 71 publications

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“…The splay is deposited as a complex of small lobes that amalgamate as crevasse‐splay channels switch and bifurcate (Smith et al ., ; Tooth, ). It expands and progrades further onto the floodplain over the course of consecutive flooding events, its size and floodwater capacity dependent on the overbank morphology and crevasse dimensions (Yuill et al ., ). The aerial extent of crevasse splays may reach up to several square kilometres (Burns et al ., ), depending primarily on sediment size and floodplain‐drainage conditions (Millard et al ., ).…”

Section: Introductionmentioning

confidence: 97%

“…The evolution of crevasse splays is often associated with avulsion of the main river (e.g. Smith et al ., ; Smith and Pérez‐Arlucea, ; Bristow et al ., ; Mohrig et al ., ; Farrell, ; Slingerland and Smith, ; Tooth, ; Hampton and Horton, ; Dalman and Weltje, ; Buehler et al ., ; Hajek and Wolinsky, ; Bernal et al ., ; Kleinhans et al ., ; Yuill et al ., ). However, the majority of crevasse splays do not lead to an avulsion of their parent channel.…”

Section: Introductionmentioning

confidence: 97%

“…bank collapse or obstruction by foreign objects (Keller and Swanson, ; Slingerland and Smith, ; Bridge, ; Bernal et al ., ). Initially, the overbank gradient and breach‐point focusing of floodwater lead to erosion and incision of crevasse‐splay channels (Yuill et al ., ), remobilizing levee sediment and the underlying substrate. Deposition occurs where the flow decelerates due to a transition from confined to unconfined flow (cf.…”

Section: Introductionmentioning

confidence: 99%

“…Yuill et al . () point out that despite being given minor attention, erosional processes play an important role in the initial phase of crevasse‐splay development.…”

Section: Introductionmentioning

confidence: 99%

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The life cycle of crevasse splays as a key mechanism in the aggradation of alluvial ridges and river avulsion

Toorenenburg

Donselaar

Weltje

2018

Earth Surf Processes Landf

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Accommodation space in the unconfined distal part of low‐gradient fluvial fans facilitates abundant floodplain deposition. Here, the development of crevasse splays plays a key role in the aggradation of alluvial ridges and subsequent river avulsion. This study presents an analysis of different stages in the evolution of crevasse splays based on observations made in the modern‐day Río Colorado dryland fluvial fan fringing the endorheic Altiplano Basin in Bolivia. A generic life cycle is proposed in which crevasse‐splay channels adjust towards a graded equilibrium profile with their lower‐lying distal termini acting as a local base level. Initial development is dominantly controlled by the outflow of floodwater, promoting erosion near the crevasse apex and deposition towards the splay fringes. When proximal incision advances to below the maximum level of floodplain inundation, return flow occurs during the waning stage of flooding. This floodwater reflux leads to a temporary repositioning of the local base level to the deeper trunk‐channel thalweg at the apex of the crevasse‐splay channels. The resultant decrease in the floodplainward gradient of these channels ultimately leads to backfilling and abandonment of the crevasse splay, leaving a subtle local elevation of the floodplain. Consecutive splays form an alluvial ridge through lateral amalgamation and subsequent vertical stacking, which is mirrored by the aggradation of their parent channel floor. As this alluvial ridge becomes increasingly perched above the surrounding floodplain, splay equilibration may cause incision of the levee crevasse down to or below its trunk channel thalweg, leading to an avulsion. The mechanisms proposed in this study are relevant to fluvial settings promoting progradational avulsions. The relatively rapid accumulation rate and high preservation potential of crevasse splays in this setting makes them an important constituent of the resultant fluvial stratigraphy, amongst which are hydrocarbon‐bearing successions. Copyright © 2018 John Wiley & Sons, Ltd.

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Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

“…Yuill et al . () point out that despite being given minor attention, erosional processes play an important role in the initial phase of crevasse‐splay development.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The life cycle of crevasse splays as a key mechanism in the aggradation of alluvial ridges and river avulsion

Toorenenburg

Donselaar

Weltje

2018

Earth Surf Processes Landf

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“…Li and Bristow [13] emphasized that high-resolution imagery in combination with field studies is an efficient way to identify a development of crevasse splays. Crevasse splays and their evolution in time were also a subject of the research conducted by Yuill et al [14].…”

Section: Introductionmentioning

confidence: 99%

Morphogenesis of a Floodplain as a Criterion for Assessing the Susceptibility to Water Pollution in an Agriculturally Rich Valley of a Lowland River

Sieczka

Bujakowski

Falkowski

et al. 2018

Water

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This study presents the results of the influence of the specific geological landforms occurring in a lowland river floodplain on the recharge and drainage conditions in an agricultural area. Particular attention has been paid to the presence of the buried erosional channels of flood waters, which may constitute the preferential paths for migration of agricultural contaminants. Moreover, the changes of effective infiltration which affect the hydrogeological regime of the tested area were analyzed. Priority was also given to the use of laboratory techniques in order to determine the parameters influencing the contaminant migration in the soil-water environment for the purpose of hydrogeological modeling. Laboratory tests, based on a column experiment, were performed in a Trautwein apparatus with reference to the constant head procedure, using conservative and reactive markers. The parameters of advection, dispersion, and sorption, obtained in the laboratory experiment were then used as the input data for the hydrodynamic model of groundwater flow and contaminant migration in the research area. Based on the created digital model of groundwater flow, the multi-variant analysis of the effect of specific geological features on the conditions of contaminant transport in a valley was performed. The presented tools and methods contributed to a significant increase in the accuracy of recognizing zones susceptible to water pollution and should be adopted in other valley areas exposed to contamination.

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Autocyclic (avulsion‐induced) base‐level change, its upstream and downstream controls, and effects on floodbasin sedimentation: The 1870s avulsion of the Saskatchewan River, Cumberland Marshes, Canada

Morozova

2021

Earth Surf Processes Landf

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This study examines centennial‐scale hydrological and sedimentological effects of floodplain inundation by avulsion and its upstream and downstream controls. The 1870s avulsion in Cumberland Marshes diverted the Saskatchewan River flow towards Cumberland Lake, a local base level. It invaded a poorly drained sub‐basin of Cumberland Marshes floodplain linked to the parent Saskatchewan River by two small outlets in the resistant substrate. The rapid increase in inflow (~5× on average) during the earlier stages of the avulsion resulted in the base‐level rise and floodplain inundation by the avulsion lake. Since the early 20th century, the forced regression of the avulsion lake occurred, caused by ~5× outlet channel enlargement by ‘hungry‐water’ outflows, whereas the mean lake inflows experienced little change. The avulsion lake served as an effective sediment trap and was filled by predominantly progradational sandy and silty avulsion deposits up to 3–4 m thick, covering about 700 km2. Elsewhere, fluviodeltaic settings with ‘negative relief’ and limited hydrologic connectivity with the rest of the floodplain may be prone to avulsion lakes that form if the rates of inflow increased by avulsion exceed the rates of outflow. Avulsion lakes can last for ~100 years or more before they drain and/or become filled by overbank sediments. On well‐drained floodplains, inundations by avulsions are expected to be short‐term and result in little progradational deposition. This study demonstrates that in some local hydrographic basins, base level becomes a variable of an evolving avulsion rather than its fixed external control. Although avulsion‐induced base‐level changes are short‐lived, they affect 102–103 km2 of a floodplain and occur rapidly, accompanied by high aggradation rates.

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Morphodynamics of the erosional phase of crevasse-splay evolution and implications for river sediment diversion function

Cited by 70 publications

References 71 publications

The life cycle of crevasse splays as a key mechanism in the aggradation of alluvial ridges and river avulsion

The life cycle of crevasse splays as a key mechanism in the aggradation of alluvial ridges and river avulsion

Morphogenesis of a Floodplain as a Criterion for Assessing the Susceptibility to Water Pollution in an Agriculturally Rich Valley of a Lowland River

Autocyclic (avulsion‐induced) base‐level change, its upstream and downstream controls, and effects on floodbasin sedimentation: The 1870s avulsion of the Saskatchewan River, Cumberland Marshes, Canada

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