Debris Flows

Ancey, Christophe

doi:10.1002/9781118619834.ch1

Cited by 5 publications

(8 citation statements)

References 109 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is generally lower than 10 m/s for events recorded in the Italian Alps (Arattano and Marchi, 1999;Tecca et al, 2003). If the debris-flow is channelized, it may travel quite a long distance over gentle slopes (Ancey, 2010). Similarly, high velocities (Vallance and Scott, 1997;Mothes et al, 2004;Muñoz-Salinas et al, 2007), exceeding even 25 m/s (Pierson, 1985), have been estimated for flows triggered by volcanic eruptions (lahars).…”

Section: Introductionmentioning

confidence: 98%

“…The distance that a debris-flow can travel greatly depends on the mechanical characteristics of the debris as well as the total volume, channel geometry and bed inclination. If the debris-flow is channelized, it may travel quite a long distance over gentle slopes (Ancey, 2010). For instance, in the case of lahars, it has been demonstrated that the flow can travel for more than 100 km over very slight slopes (less than 1%) (Scott et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reconstruction of a destructive debris‐flow event via numerical modeling: the role of valley geometry on flow dynamics

Schilirò

Blasio

Esposito

et al. 2015

Earth Surf Processes Landf

View full text Add to dashboard Cite

Debris‐flows are widespread natural phenomena characterized by high mobility (high velocity and long runout distance) and impact forces, which frequently cause human casualties and significant damage to infrastructure. To better understand the dynamics of such events, analyzing in particular the effect induced by the valley geometry on flow velocity, runout and mobilized volumes, in this work we reconstruct a real debris‐flow event through numerical modeling. Specifically, we used a modified version of the BING model, a fluid‐dynamic depth‐integrated numerical model for debris flows, which has been properly modified to account for width changes along the valley. The studied event, which occurred in Scaletta Zanclea (Messina, north‐eastern Sicily, Italy) on October 1, 2009, is exceptionally well constrained by field and topographic information. In this respect the flow velocity, estimated from two specific locations on the basis of field evidence, the distribution of erosional and depositional areas along the Racinazzo valley, based on the comparison of pre‐ and post‐event digital elevation models (DEMs), and the runout distance were used as constraints to calibrate the model. Furthermore, we report a detailed description of the main event characteristics based on hydrological records and witness reports. The numerical modeling results are consistent with witness reports and the severe damage recorded in the Scaletta Marina village, and highlight the effect of the valley geometry on both the debris flow velocity and the erosion/deposition processes. The effect of changing valley width has been also quantified, resulting in accelerations of the debris in correspondence of the valley narrowing and stagnations at the plateaus. Copyright © 2015 John Wiley & Sons, Ltd.

show abstract

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Reconstruction of a destructive debris‐flow event via numerical modeling: the role of valley geometry on flow dynamics

Schilirò

Blasio

Esposito

et al. 2015

Earth Surf Processes Landf

View full text Add to dashboard Cite

show abstract

“…Meanwhile, the mean annual stream discharge was found to range between 0.19 (Dabnitsa gauge) and 5.88 m 3 /s (Yugovo gauge). Moreover, while seven gauging stations with drainage area ranging between 452-4947 km 2 are located in the area, these streams cannot be considered as torrential streams that typically vary from 0.1 to 100 km 2 [19] or about 300 km 2 , according to other studies [17,18]. For this reason, the latter watersheds were excluded from any further analysis.…”

Section: Study Area and Datasets Descriptionmentioning

confidence: 99%

Generating Regional Models for Estimating the Peak Flows and Environmental Flows Magnitude for the Bulgarian-Greek Rhodope Mountain Range Torrential Watersheds

Myronidis

Ivanova

2020

Water

View full text Add to dashboard Cite

The flood magnitudes with 25, 50, and 100 years return periods and the environmental flows (Qenv) are of outmost importance in the context of hydraulic and hydrologic design. In this study, 25 watershed characteristics were linked with the aforementioned recurrence intervals, peak discharge values, as well as Qenv for 15 pristine torrential watersheds with more than 10 years of streamflow records in the Rhodopi mountain range with a view to generating regional relationships for the assessment of discharge annual peaks and environmental flows regarding the ungauged torrential watersheds in the region. The Log-Pearson Type III probability distribution was fitted in the discharge annual peaks time series, so as to predict Q25, Q50, and Q100, whereas the Tennant method was utilised so as to estimate the environmental flows magnitude. Similarly, the Kolmogorov–Smirnov and the Anderson–Darling tests were performed to verify the distribution fitting. The Principal Components Analysis method reduced the explanatory variables number to 14, whilst the stepwise multiple regression analysis indicated that the exponential model is suitable for predicting the Q25, the power model best forecasted the Q50 and Q100, whereas the linear model is appropriate for Qenv prognosis. In addition, the reliability of the obtained regression models was evaluated by employing the R2, the Nash–Sutcliffe efficiency, and the Index of Agreement Statistical Criteria, which were found to range from 0.91–0.96, 0.88–0.95 and 0.97–0.99, respectively, thereby denoting very strong and accurate forecasts by the generated equations. Thus, the developed equations could successfully predict the peak discharge values and environmental flows within the region’s ungauged watersheds with the drainage size not exceeding 330 km2.

show abstract

“…Furthermore, torrential catchments are small in size (i.e., typically less than 100 km 2 ), characterised by a steep terrain and susceptible to the occurrence of sudden, short and violent flood events [34]. However, these are also the characteristic features of catchments prone to flash flooding [19], with shock-capturing flood inundation models already identified as the most appropriate type of flood inundation models for modelling in such areas [10].…”

Section: Idealised Valley Test Casementioning

confidence: 99%

“…These results are particularly interesting when one considers how river streams/catchments are generally divided according to the value of the bed slope. In particular, rivers are often defined as having a bed slope that is less than 1%, torrential rivers have a bed slope ranging from 1 to 6%, and finally streams are often referred to as torrents when the bed slope is greater than 6% [34]. This means that the value of the bed slope that is used to distinguish between a river and a torrential river (i.e., river and torrential catchments) is similar to the value of the bed slope at which the water depth predictions from the considered three model configurations started to differ more significantly.…”

Section: Idealised Valley Test Casementioning

confidence: 99%

Flood Inundation Modelling of Flash Floods in Steep River Basins and Catchments

Kvočka¹,

Ahmadian²,

Falconer³

2017

Water

View full text Add to dashboard Cite

Abstract:The potential flood inundation extent can be estimated with flood inundation models, which can differ in the level of physical and numerical modelling complexity included in the solution procedure. In recent years, several studies have highlighted the benefits of shock-capturing flood inundation models, particularly when modelling a high Froude number or supercritical flows, or in areas prone to the occurrence of rapidly varying flood events, such as flash floods. Nonetheless, decision makers are often reluctant to implement more complex modelling tools into practical flood inundation modelling studies, unless evidence is provided to establish when such refined modelling tools should be used. The main objective of this study was to determine a general threshold value of the bottom slope that could be used by decision makers as an orientation guide to ascertain when to use a specific type of flood inundation model. The results obtained suggest that in torrential river basins or catchments (i.e., river basins and catchments with a bed slope generally greater than 1%), the flood inundation modelling should be conducted by using a flood inundation model that include shock-capturing algorithms in the model solution procedure.

show abstract

Debris Flows

Cited by 5 publications

References 109 publications

Reconstruction of a destructive debris‐flow event via numerical modeling: the role of valley geometry on flow dynamics

Reconstruction of a destructive debris‐flow event via numerical modeling: the role of valley geometry on flow dynamics

Generating Regional Models for Estimating the Peak Flows and Environmental Flows Magnitude for the Bulgarian-Greek Rhodope Mountain Range Torrential Watersheds

Flood Inundation Modelling of Flash Floods in Steep River Basins and Catchments

Contact Info

Product

Resources

About