Downstream hydraulic geometry relationships: Gathering reference reach-scale width values from LiDAR

Sofia, Giulia; Tarolli, Paolo; Cazorzi, Federico; Fontana, Giancarlo Dalla

doi:10.1016/j.geomorph.2015.09.002

Cited by 22 publications

(28 citation statements)

References 97 publications

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“…A range of θ between about 0.4 and 0.7 has been found under relatively homogeneous conditions (e.g., Whipple, 2004;Whipple et al, 2013), while a wider range from less than 0.2 in steep headwater channels to more than 1 in some alluvial channels has been reported (Brummer and Montgomery, 2003;Montgomery, 2001;Sofia et al, 2015). Apparent variations in θ may also arise from spatial inhomogeneity or non-steady topography.…”

Section: Introductionmentioning

confidence: 96%

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the <i>χ</i> method

2016

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Abstract. Quantitative tectonic geomorphology hinges on the analysis of longitudinal river profiles. The model behind almost all approaches in this field originates from an empirical relationship between channel slope and catchment size, often substantiated in the form of the stream-power model for fluvial incision. Significant methodological progress was recently achieved by introducing the χ transform. It defines a nonlinear length coordinate in such a way that the inherent curvature of river profiles due to the increase of catchment sizes in the downstream direction is removed from the analysis. However, the limitation to large catchment sizes inherited from the stream-power approach for fluvial incision persists. As a consequence, only a small fraction of all nodes of a digital elevation model (DEM) can be used for the analysis. In this study we present and discuss some empirically derived extensions of the stream power law towards small catchment sizes in order to overcome this limitation. Beyond this, we introduce a simple method for estimating the adjustable parameters in the original χ method as well as in our extended approaches. As a main result, an approach originally suggested for debris flow channels seems to be the best approximation if both large and small catchment sizes are included in the same analysis.

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Section: Introductionmentioning

confidence: 96%

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the <i>χ</i> method

2016

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“…Among the investigated Dolomitic rivers, some examples are worth to be analysed more in detail. The Rio Cordevole is characterized, in its upper part ( L ≤ ~1000 m), by limited vertical incision, and therefore erosion is mostly expended in width adjustment, rather than in channel deepening (Vianello & D'Agostino, ; Sofia et al, ).…”

Section: Resultsmentioning

confidence: 99%

Morphological Similarity of Channels: From Linear Erosional Features (Rill, Gully) to Alpine Rivers

et al. 2017

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The geometric characteristics of incised features such as channels, rills, ephemeral gully, gully, represent the erosional transport regime and the fluvial dynamic equilibrium, and thus it is critical for the understanding of the long‐term evolution of natural, agricultural, and anthropogenic landscapes. This paper examines the morphological similarity of channelized erosion in two different environments such as Alpine landscapes and cultivated hillslopes. The first dataset comprises six rivers in the Italian Alps, three in the Carnia region and three in the Dolomites, where erosion is mainly the effect of discharges with high sediment loads or landslides and debris flows. The agricultural areas dataset includes rills, ephemeral gullies, and gullies surveyed in literature. This research highlights that the eroded volume in Alpine rivers is in line with that of agricultural landscapes or badlands around the world. Dolomites rivers of colluvial origin, flowing on soils that are not particularly deep and subject to natural disaggregation, tend to behave similarly to ephemeral gullies. Contrarily, channels that exhibit evident alluvial morphologies and coarse grain sizes are more similar to gully erosion. At different spatial scales, the results demonstrated that length–volume equations calibrated on rills, ephemeral gullies, gullies and badlands, might be feasible also for Alpine channels. The research areas present soils and bedrock lithology that differs from those in literature, thus suggesting that the morphology of linear erosion is independent of the intrinsic soil characteristics. Differences emerged between Dolomites and Carnia rivers: this highlights the importance of taking into account in future analyses other forcing factors (e.g. climate) on land degradation processes. Copyright © 2017 John Wiley & Sons, Ltd.

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“…Channel width has been shown to be estimated expediently via remote sensing methods (e.g., [126,[148][149][150][151][152][153][154]), air photo interpretation (e.g., [155]) and application of Google Earth imagery (e.g., [156,157]) with considerable benefits over established methodologies (see [158] for issues with map-based width measurement). However, where data are available two problematic areas remain: accuracy where banklines are obscured in images or where scans are unreliably filtered for vegetation [141]; wetted width at the time of survey is merely a snapshot of the geometry and might not represent either the bankfull or a temporally-averaged condition [143].…”

Section: Cross-sections and Slopementioning

confidence: 99%

Quantifying River Channel Stability at the Basin Scale

Soar

Wallerstein

Thorne

2017

Water

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This paper examines the feasibility of a basin-scale scheme for characterising and quantifying river reaches in terms of their geomorphological stability status and potential for morphological adjustment based on auditing stream energy. A River Energy Audit Scheme (REAS) is explored, which involves integrating stream power with flow duration to investigate the downstream distribution of Annual Geomorphic Energy (AGE). This measure represents the average annual energy available with which to perform geomorphological work in reshaping the channel boundary. Changes in AGE between successive reaches might indicate whether adjustments are likely to be led by erosion or deposition at the channel perimeter. A case study of the River Kent in Cumbria, UK, demonstrates that basin-wide application is achievable without excessive field work and data processing. However, in addressing the basin scale, the research found that this is inevitably at the cost of a number of assumptions and limitations, which are discussed herein. Technological advances in remotely sensed data capture, developments in image processing and emerging GIS tools provide the near-term prospect of fully quantifying river channel stability at the basin scale, although as yet not fully realized. Potential applications of this type of approach include system-wide assessment of river channel stability and sensitivity to land-use or climate change, and informing strategic planning for river channel and flood risk management.

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Downstream hydraulic geometry relationships: Gathering reference reach-scale width values from LiDAR

Cited by 22 publications

References 97 publications

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the <i>χ</i> method

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the <i>χ</i> method

Morphological Similarity of Channels: From Linear Erosional Features (Rill, Gully) to Alpine Rivers

Quantifying River Channel Stability at the Basin Scale

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Downstream hydraulic geometry relationships: Gathering reference reach-scale width values from LiDAR

Cited by 22 publications

References 97 publications

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the &lt;i&gt;χ&lt;/i&gt; method

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the &lt;i&gt;χ&lt;/i&gt; method

Morphological Similarity of Channels: From Linear Erosional Features (Rill, Gully) to Alpine Rivers

Quantifying River Channel Stability at the Basin Scale

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Product

Resources

About

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the <i>χ</i> method

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the <i>χ</i> method