Field observations, experiments, and modeling of sediment production from freeze and thaw action on a bare, weathered granite slope in a temperate region of Japan

High‐resolution topography data sets have improved the spatial and temporal scales at which we are able to investigate the landscape through the analysis of landform attributes and the computation of topographic changes. Yet, to date, there have been only limited attempts to infer key geomorphic processes in terms of contributions to shaping the landscape. Highly erodible landscapes such as badlands provide an ideal demonstration of such an approach owing to the rapid changes observed over a relatively short time frame. In this technical note we present the Mapping Geomorphic Processes in the Environment (MaGPiE): a new algorithm that allows mapping of geomorphic process signatures through analysis of repeat high‐resolution topography data sets. The method is demonstrated in an experimental badland located in the southern central Pyrenees. MaGPiE is a geographic information system (GIS)‐based algorithm that uses as input: (a) terrain attributes (i.e. Slope, Roughness and Concentrated Runoff Index) extracted from digital elevation models (DEMs), and (b) a map of topographic changes (DEM of difference, DoD). Initial results demonstrate that MaGPiE allows the magnitude and the spatial distribution of the main geomorphic processes reshaping badlands to be inferred for the first time. © 2020 John Wiley & Sons, Ltd.

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“…only 13 days with T < 0°C). Similar observations were made in Barnes et al (2016) and Tsutsumi and Fujita (2016).…”

Section: Resultssupporting

confidence: 88%

Geomorphic process signatures reshaping sub‐humid Mediterranean badlands: 1. Methodological development based on high‐resolution topography

Llena

Vericat

Smith

et al. 2020

Earth Surf Processes Landf

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“…6). It has been reported that the flow velocity is higher over frozen soil than over thawed soil because of the lower infiltration capacity (Gatto et al, 2001;Tsutsumi and Fujita, 2016), smooth surface , and lower runoff energy consumption (Wang et al, 2018). These conclusions were obtained from compacted soil frozen under controlled laboratory conditions.…”

Section: Lagging Of Runoff Generation Time and Hindering Of Flow Velocitymentioning

confidence: 92%

Field experimental study on the effect of thawed depth of frozen alpine meadow soil on rill erosion by snowmelt waterflow

Shi

Zhang

Lei

et al. 2020

Preprint

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Soil erosion by snow or ice melt waterflow is an important type of soil erosion in many high-altitude and high-latitude regions. The snowmelt waterflow erosion process, affected by soil freeze and thaw, is highly dynamically variable. In this study, field experiments were conducted to investigate the effects of thawed depth of frozen soil profile on snowmelt waterflow erosion of alpine meadow soil in the spring. The experiments involved five thawed depths from 0 to 100 mm under two snowmelt waterflow rates of 3 L/min and 5 L/min. The unthawed soil or shallow-thawed depth of 10 mm significantly altered the runoff and sediment production mechanism, including a significant delay of the runoff generation time and change of hydrograph and sedigraph. When the soil was frozen, the topsoil was structured with large open voids, to retain water and impede flow. This resulted in runoff generation time that was greatly lagged and soil erosion in the initial stage that was inhibited. The relationship curve of runoff and sediment concentration showed two-stage patterns that characterized a limited sediment supply in the early stage and hydrodynamic-controlled processes in the later stage. The deep-thawed cases ([?] 30 mm) showed similar hydrograph and sedigraph patterns with unfrozen soil condition. The findings of this study provide guidance for the future improvement of erosion model of partially thawed soil. Keywords: snowmelt waterflow erosion; thawed soil depth; soil freeze and thaw; runoff generation; sediment rating curve Field experimental study on the effect of thawed depth of frozen alpine meadow soil on rill erosion by snowmelt waterflow

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“…Surface rising associated with this process is mostly due to the fracture of the regolith caused by both the freezethaw (e.g. Barnes et al, 2016;Tsutsumi and Fujita, 2016) and moisture-change cycles (e.g. Nadal-Romero and Regüés, 2010).…”

Section: Topographic Changesmentioning

confidence: 99%

Geomorphic process signatures reshaping sub‐humid Mediterranean badlands: 2. Application to 5‐year dataset

Llena

Smith

Wheaton

et al. 2020

Earth Surf Processes Landf

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Badland landscapes exhibit high erosion rates and represent the main source of fine sediments in some catchments. Advances in high‐resolution topographic methods allow analysis of topographic changes at high temporal and spatial scales. We apply the Mapping Geomorphic Processes in the Environment (MaGPiE) algorithm to infer the main geomorphic process signatures operating in two sub‐humid badlands with contrasting morphometric attributes located in the Southern Pyrenees. By interrogating a 5‐year dataset of seasonal and annual topographic changes, we examine the variability of geomorphic processes at multiple temporal scales. The magnitude of geomorphic processes is linked to landform attributes and meteorological variables. Morphometric differences between both adjacent badlands allow us to analyse the role of landform attributes in the main geomorphic process reshaping landscapes subjected to the same external forcing (i.e. rainfall and temperature). The dominant geomorphic process signatures observed in both badlands are different, despite their close proximity and the same rainfall and temperature regimes. Process signatures determining surface lowering in the gently sloping south‐facing badland, characterized by lower connectivity and more vegetation cover, are driven by surface runoff‐based processes, both diffuse (causing sheet washing) and concentrated (determining cutting and filling, rilling and gullying). The steeper, more connected north‐facing slopes of the other badland are reshaped by means of gravitational processes, with mass wasting dominating topographic changes. In terms of processes determining surface raising, both mass wasting and cutting and filling are most frequently observed in both badlands. There is a clear near‐balanced feedback between both surface‐raising and ‐lowering processes that becomes unbalanced at larger temporal scales due to the thresholds overcome, as the volume associated with surface lowering becomes higher than that associated with raising‐based processes. Rainfall variables control surface flow processes, while those variables associated with low temperature have a significant relation with mass movement‐based processes and other localized processes such as regolith cohesion loss. Finally, our results point out that morphometry (slope and connectivity) together with vegetation cover are key factors determining geomorphic processes and associated topographic changes. © 2020 John Wiley & Sons, Ltd.

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Field observations, experiments, and modeling of sediment production from freeze and thaw action on a bare, weathered granite slope in a temperate region of Japan

Cited by 13 publications

References 17 publications

Geomorphic process signatures reshaping sub‐humid Mediterranean badlands: 1. Methodological development based on high‐resolution topography

Geomorphic process signatures reshaping sub‐humid Mediterranean badlands: 1. Methodological development based on high‐resolution topography

Field experimental study on the effect of thawed depth of frozen alpine meadow soil on rill erosion by snowmelt waterflow

Geomorphic process signatures reshaping sub‐humid Mediterranean badlands: 2. Application to 5‐year dataset

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