Effects of silt–clay content on the susceptibility of river banks to subaerial erosion

Couper, Pauline

doi:10.1016/s0169-555x(03)00048-5

Cited by 90 publications

(81 citation statements)

References 26 publications

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“…In addition to the fluvial activity, Bank 2 is subject to direct rainfall impact as well as snowmelt, since the bank is characterized by a mild steepness (Table 1). Moreover, many authors published works, in which they link the compromised strength of the shallow layers of the soil during and after freeze-thaw cycles, and an acceleration in erosion processes due to the presence of excessive soil water from melted ground ice [85][86][87][88][89]. It has been noted that boulders of larger size remain static since the slope of this bank is not characterized by such a severe steepness, and therefore the destabilizing action of gravity is reduced.…”

Section: Resultsmentioning

confidence: 99%

Monitoring Riverbank Erosion in Mountain Catchments Using Terrestrial Laser Scanning

et al. 2016

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Sediment yield is a key factor in river basins management due to the various and adverse consequences that erosion and sediment transport in rivers may have on the environment. Although various contributions can be found in the literature about sediment yield modeling and bank erosion monitoring, the link between weather conditions, river flow rate and bank erosion remains scarcely known. Thus, a basin scale assessment of sediment yield due to riverbank erosion is an objective hard to be reached. In order to enhance the current knowledge in this field, a monitoring method based on high resolution 3D model reconstruction of riverbanks, surveyed by multi-temporal terrestrial laser scanning, was applied to four banks in Val Tartano, Northern Italy. Six data acquisitions over one year were taken, with the aim to better understand the erosion processes and their triggering factors by means of more frequent observations compared to usual annual campaigns. The objective of the research is to address three key questions concerning bank erosion: "how" erosion happens, "when" during the year and "how much" sediment is eroded. The method proved to be effective and able to measure both eroded and deposited volume in the surveyed area. Finally an attempt to extrapolate basin scale volume for bank erosion is presented.

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Section: Resultsmentioning

confidence: 99%

Monitoring Riverbank Erosion in Mountain Catchments Using Terrestrial Laser Scanning

et al. 2016

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“…As such, our study represents a rare data set available to researchers interested in testing theories of spatial patterns of bank erosion (e.g., Marcus, 2003, 2010) or identifying factors contributing to recession rate variability within a basin (e.g., Couper, 2003;Laubel et al, 2003;Henshaw et al, 2012). For example, Walnut Creek watershed results are being used to evaluate the effects of hydraulic disturbance (channelization) on the relations of channel sinuosity, stream power and occurrences of severe bank erosion.…”

Section: Future Workmentioning

confidence: 99%

Streambank erosion rates and loads within a single watershed: Bridging the gap between temporal and spatial scales

et al. 2014

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The importance of streambank erosion to watershed-scale sediment export is being increasingly recognized. However few studies have quantified bank erosion and watershed sediment flux at the basin scale across temporal and spatial scales. In this study we evaluated the spatial distribution, extent, and temporal frequency of bank erosion in the 5218 ha Walnut Creek watershed in Iowa across a seven year period. We inventoried severely eroding streambanks along over 10 km of stream and monitored erosion pins at 20 sites within the watershed. Annual streambank recession rates ranged from 0.6 cm/yr during years of hydrological inactivity to 28.2 cm/yr during seasons with high discharge rates, with an overall average of 18.8 cm/yr. The percentage of total basin export attributed to streambank erosion along the main stem of Walnut Creek ranged from 23 to 53%. Large variations in individual site, annual rates and percentage of annual load suggested that developing direct relationships between streambank erosion rates and total sediment discharge may be confounded by the timing and magnitude of discharge events, storage of sediments within channel system and the remobilization of eroded material. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. The importance of streambank erosion to watershed-scale sediment export is being increasingly recognized. However few studies have quantified bank erosion and watershed sediment flux at the basin scale across temporal and spatial scales. In this study we evaluated the spatial distribution, extent, and temporal frequency of bank erosion in the 5218 ha Walnut Creek watershed in Iowa across a seven year period. We inventoried severely eroding streambanks along over 10 km of stream and monitored erosion pins at 20 sites within the watershed. Annual streambank recession rates ranged from 0.6 cm/yr during years of hydrological inactivity to 28.2 cm/yr during seasons with high discharge rates, with an overall average of 18.8 cm/yr. The percentage of total basin export attributed to streambank erosion along the main stem of Walnut Creek ranged from 23 to 53%. Large variations in individual site, annual rates and percentage of annual load suggested that developing direct relationships between streambank erosion rates and total sediment discharge may be confounded by the timing and magnitude of discharge events, storage of sediments within channel system and the remobilization of eroded material.

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“…Although seepage erosion has been directly quantified (Fox et al, 2007b), only early attempts have been made at developing regression models (Fox et al, 2007a(Fox et al, , 2006 and mechanistic models (Chu-Agor et al, 2008aFox and Felice, 2014) to predict erosion rates. Subaerial processes are controlled by freeze/thaw and wetting/drying cycles which loosens exposed soil (Couper and Maddock, 2001;Couper, 2003). Climatological variables, including the number of freeze/thaw cycles and the number of days with frost have been shown to be correlated with subaerial erosion rates (Couper and Maddock, 2001;Pizzuto, 2009), but these variables control soil moisture content, the main driver of subaerial erosion (Thorne, 1982).…”

Section: Limitations Of This Study and Bstemmentioning

confidence: 99%

Uncertainty and sensitivity in a bank stability model: implications for estimating phosphorus loading

Lammers

Bledsoe

Langendoen

2016

Earth Surf Processes Landf

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UNCERTAINTY AND SENSITIVITY IN A BANK STABILITY MODEL: IMPLICATIONS FOR ESTIMATING PHOSPHORUS LOADINGEutrophication of aquatic ecosystems is one of the most pressing water quality concerns in the U.S. and around the world. Bank erosion has been largely overlooked as a source of nutrient loading, despite field studies demonstrating that this source can account for the majority of the total phosphorus budget of a watershed. Substantial effort has been made to develop mechanistic models to predict bank erosion and instability in stream systems; however, these models do not account for inherent natural variability in input values. Providing only single output values with no quantification of associated uncertainty can complicate management decisions focused on reducing bank erosion and nutrient loading to streams. To address this issue, uncertainty and sensitivity analyses were performed on the Bank Stability and Toe Erosion Model (BSTEM), a mechanistic model developed by the USDA-ARS that simulates both mass wasting (stability) and fluvial erosion of streambanks. Sensitivity analysis results indicate that variable influence on model output can vary depending on assumed input distributions.Generally, bank height, soil cohesion, and plant species were found to be most influential in determining stability of clay (cohesive) banks. In addition to these three inputs, groundwater elevation, stream stage, and bank angle were also identified as important in sand (non-cohesive) banks. Slope and bank height are the dominant variables in fluvial erosion modeling, while erodibility and critical shear stress are relatively unimportant. However, the threshold effect of critical shear stress (determining whether erosion occurs) was not explicitly accounted for, ii possibly explaining the relatively low sensitivity indices for this variable. Model output distributions of sediment and phosphorus loading rates corresponded well to ranges published in the literature, helping validate both model performance and selected ranges of input values. In addition, a probabilistic modeling approach was applied to data from a watershed-scale sediment and phosphorus loading study on the Missisquoi River, Vermont to quantify uncertainty associated with these published results. While our estimates indicated that bank erosion was likely a significant source of sediment and phosphorus to the watershed in question, the uncertainty associated with these predictions indicates that they should probably be considered order of magnitude estimates only.iii ACKNOWLEDGEMENTS

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Effects of silt–clay content on the susceptibility of river banks to subaerial erosion

Cited by 90 publications

References 26 publications

Monitoring Riverbank Erosion in Mountain Catchments Using Terrestrial Laser Scanning

Monitoring Riverbank Erosion in Mountain Catchments Using Terrestrial Laser Scanning

Streambank erosion rates and loads within a single watershed: Bridging the gap between temporal and spatial scales

Uncertainty and sensitivity in a bank stability model: implications for estimating phosphorus loading

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