Lateral bedrock erosion and valley formation in a heterogeneously layered landscape, Northeast Kansas

Marcotte, Abbey L.; Neudorf, Christina M.; Langston, Abigail L.

doi:10.1002/esp.5172

Cited by 11 publications

(10 citation statements)

References 78 publications

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“…River valleys evolve by deepening through vertical river incision and widening through lateral erosion of valley walls (Figure 1). Whereas much emphasis has been put on investigating processes and rates of vertical incision (e.g., Tucker & Slingerland, 1997; Tucker & Whipple, 2002), our limited knowledge on parameters controlling valley widening and valley‐bottom width prevents us from interpreting the range of valley geometries that occur in nature and predicting how valleys evolve under changing environmental conditions (Langston & Tucker, 2018; Marcotte et al., 2021).…”

Section: Introductionmentioning

confidence: 99%

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Hillslope Sediment Supply Limits Alluvial Valley Width

2022

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River valleys set the relief of eroding landscapes, control the habitat and distribution of many species, and influence the direction of nutrient and water fluxes across large parts of Earth's surface (Hilton & West, 2020;Macklin & Lewin, 2015;May et al., 2013). The range of valley widths and depths that occur on Earth spans from meters to multiple kilometers, and constraining processes and controls on the formation of river valleys is a key component of understanding landscape development (Perron et al., 2009;Tucker & Slingerland, 1997;Willett et al., 2014). River valleys evolve by deepening through vertical river incision and widening through lateral erosion of valley walls (Figure 1). Whereas much emphasis has been put on investigating processes and rates of vertical incision (e.g., Tucker & Slingerland, 1997;Tucker & Whipple, 2002), our limited knowledge on parameters controlling valley widening and valley-bottom width prevents us from interpreting the range of valley geometries that occur

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Section: Introductionmentioning

confidence: 99%

“…in nature and predicting how valleys evolve under changing environmental conditions (Langston & Tucker, 2018;Marcotte et al, 2021).…”

mentioning

confidence: 99%

Hillslope Sediment Supply Limits Alluvial Valley Width

2022

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“…Lateral migration of channels may be an important control on both channel profiles (Finnegan and Dietrich, 2011) and the evolution of drainage networks over geological timescales (Kwang et al, 2021). Some studies have suggested that lateral erosion rates can outpace those of vertical incision (Suzuki, 1982;Cook et al, 2014;Marcotte et al, 2021), yet research into rates and mechanisms of lateral erosion is distinctly lacking compared to vertical bedrock incision.…”

Section: Introductionmentioning

confidence: 99%

Continuous measurements of valley floor width in mountainous landscapes

2022

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Abstract. Mountainous landscapes often feature alluviated valleys that control both ecosystem diversity and the distribution of human populations. Alluviated, flat valley floors also play a key role in determining flood hazard in these landscapes. Various mechanisms have been proposed to control the spatial distribution and width of valley floors, including climatic, tectonic, and lithologic drivers. Attributing one of these drivers to observed valley floor widths has been hindered by a lack of reproducible, automated valley extraction methods that allow continuous measurements of valley floor width at regional scales. Here, we present a new method for measuring valley floor width in mountain landscapes from digital elevation models (DEMs). This method first identifies valley floors based on thresholds of slope and elevation compared to the modern channel and uses these valley floors to extract valley centrelines. It then measures valley floor width orthogonal to the centreline at each pixel along the channel. The result is a continuous measurement of valley floor width at every pixel along the valley, allowing us to constrain how valley floor width changes downstream. We demonstrate the ability of our method to accurately extract valley floor widths by comparing with independent Quaternary fluvial deposit maps from sites in the UK and the US. We find that our method extracts similar downstream patterns of valley floor width to the independent datasets in each site, with a mean width difference of 17–69 m. The method works best in confined valley settings and will not work in unconfined valleys where the valley walls are not easily distinguished from the valley floor. We then test current models of lateral erosion by exploring the relationship between valley floor width and drainage area in the Appalachian Plateau, USA, selected because of its tectonic quiescence and relatively homogeneous lithology. We find that an exponent relating width and drainage area (cv=0.3±0.06) is remarkably similar across the region and across spatial scales, suggesting that valley floor width evolution is driven by a combination of both valley wall undercutting and wall erosion in the Appalachian Plateau. Finally, we suggest that, similar to common metrics used to explore vertical incision, our method provides the potential to act as a network-scale metric of lateral fluvial response to external forcing.

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“…Valley and channel width further plays a central role in landscape evolution (Amos and Burbank, 2007;Fisher et al, 2013;Hancock and Anderson, 2002). The relation between valley width, which subsumes channels, terraces, and floodplains, and other measures of valley morphology, including depth and fill thickness, is used to elucidate drainage evolution over geological timescales (e.g., Gibling, 2006;Schumm and Ethridge, 1994) and for inferring past climate changes (e.g., Dury, 1964;Hancock and Anderson, 2002;Marcotte et al, 2021) and tectonic variations (Giaconia et al, 2012). The channel width is a key component in landscape evolution for its control on the shear stress exerted by the flowing water, sediment transport capacity, and erosion rate (Whittaker et al, 2007b;Yanites et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, in such landscapes, a more complex scaling involving channel width, area, and slope was shown to be more applicable (Finnegan et al, 2005). While the influence of tectonic, climatic, and lithologic changes on valley and channel width has been extensively explored (e.g., Allen et al, 2013;Keen-Zebert et al, 2017;Marcotte et al, 2021), the effects of drainage reorganization, which imposes drainage area transiency, were mostly overlooked. The current study targets these effects by exploring valley and channel width scaling under transient conditions that emerge from processes of drainage reorganization.…”

Section: Introductionmentioning

confidence: 99%

Drainage reorganization induces deviations in the scaling between valley width and drainage area

et al. 2022

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Abstract. The width of valleys and channels affects the hydrology, ecology, and geomorphic functionality of drainage networks. In many studies, the width of valleys and/or channels (W) is estimated as a power-law function of the drainage area (A), W=kcAd. However, in fluvial systems that experience drainage reorganization, abrupt changes in drainage area distribution can result in valley or channel widths that are disproportional to their drainage areas. Such disproportionality may be more distinguished in valleys than in channels due to a longer adjustment timescale for valleys. Therefore, the valley width–area scaling in reorganized drainages is expected to deviate from that of drainages that did not experience reorganization. To explore the effect of reorganization on valley width–drainage area scaling, we studied 12 valley sections in the Negev desert, Israel, categorized into undisturbed, beheaded, and reversed valleys. We found that the values of the drainage area exponents, d, are lower in the beheaded valleys relative to undisturbed valleys but remain positive. Reversed valleys, in contrast, are characterized by negative d exponents, indicating valley narrowing with increasing drainage area. In the reversed category, we also explored the independent effect of channel slope (S) through the equation W=kbAbSc, which yielded negative and overall similar values for b and c. A detailed study in one reversed valley section shows that the valley narrows downstream, whereas the channel widens, suggesting that, as hypothesized, the channel width adjusts faster to post-reorganization drainage area distribution. The adjusted narrow channel dictates the width of formative flows in the reversed valley, which contrasts with the meaningfully wider formative flows of the beheaded valley across the divide. This difference results in a step change in the unit stream power between the reversed and beheaded channels, potentially leading to a “width feedback” that promotes ongoing divide migration and reorganization. Our findings demonstrate that valley width–area scaling is a potential tool for identifying landscapes influenced by drainage reorganization. Accounting for reorganization-specific scaling can improve estimations of erosion rate distributions in reorganized landscapes.

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Lateral bedrock erosion and valley formation in a heterogeneously layered landscape, Northeast Kansas

Cited by 11 publications

References 78 publications

Hillslope Sediment Supply Limits Alluvial Valley Width

Hillslope Sediment Supply Limits Alluvial Valley Width

Continuous measurements of valley floor width in mountainous landscapes

Drainage reorganization induces deviations in the scaling between valley width and drainage area

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