Coupled prediction of flash flood response and debris flow occurrence: Application on an alpine extreme flood event

Abstract The concurrence of flash floods and debris flows is of particular concern, because it may amplify the hazard corresponding to the individual generative processes. This paper presents a coupled modelling framework for the predictions of flash flood response and of the occurrence of debris flows initiated by channel bed mobilization. The framework combines a spatially distributed flash flood response model and a debris flow initiation model to define a threshold value for the peak flow which permits identification of channelized debris flow initiation. The threshold is defined over the channel network as a function of the upslope area and of the local channel bed slope, and it is based on assumptions concerning the properties of the channel bed material and of the morphology of the channel network. The model is validated using data from an extreme rainstorm that impacted the 140 km 2 Vizze basin in the Eastern Italian Alps on August 4–5, 2012. The results show that the proposed methodology has improved skill in identifying the catchments where debris-flows are triggered, compared to the use of simpler thresholds based on rainfall properties.

[1]  A. Barros,et al.  Coupled prediction of flood response and debris flow initiation during warm and cold season events in the Southern Appalachians, USA , 2013 .

[2]  J. Coe,et al.  Introduction to the special issue on debris flows initiated by runoff, erosion, and sediment entrainment in western North America , 2008 .

[3]  Leonardo Noto,et al.  Physically based modeling of rainfall-triggered landslides: a case study in the Luquillo Forest, Puerto Rico , 2013 .

[4]  Francesco Marra,et al.  Radar rainfall estimation for the identification of debris-flow occurrence thresholds , 2014 .

[5]  David A. Kinner,et al.  Initiation conditions for debris flows generated by runoff at Chalk Cliffs, central Colorado , 2008 .

[6]  G. Dalla Fontana,et al.  The triggering of debris flow due to channel‐bed failure in some alpine headwater basins of the Dolomites: analyses of critical runoff , 2008 .

[7]  Konstantine P. Georgakakos,et al.  Regional bankfull geometry relationships for southern California mountain streams and hydrologic applications , 2014 .

[8]  E. Anagnostou,et al.  Flash flood forecasting, warning and risk management: the HYDRATE project , 2011 .

[9]  Giacomo Bertoldi,et al.  Modelling the probability of occurrence of shallow landslides and channelized debris flows using GEOtop‐FS , 2008 .

[10]  G. Jennings,et al.  Morphology Characteristics of Southern Appalachian Wilderness Streams 1 , 2012 .

[11]  Eric Gaume,et al.  Extreme flood response to short-duration convective rainfall in South-West Germany , 2011 .

[12]  Richard M. Iverson,et al.  Landslide triggering by rain infiltration , 2000 .

[13]  Giulia Sofia,et al.  Downstream hydraulic geometry relationships: Gathering reference reach-scale width values from LiDAR , 2015 .

[14]  Jeffrey A. Coe,et al.  Alpine debris flows triggered by a 28 July 1999 thunderstorm in the central Front Range, Colorado , 2007 .

[15]  M. Jakob,et al.  The significance of channel recharge rates for estimating debris‐flow magnitude and frequency , 2005 .

[16]  C. Gregoretti.  The initiation of debris flow at high slopes: experimental results , 2000 .

[17]  J. Smith,et al.  Catastrophic flooding from an orographic thunderstorm in the central Appalachians , 2005 .

[18]  Lorenzo Marchi,et al.  Monitoring sediment source areas in a debris-flow catchment using terrestrial laser scanning , 2014 .

[19]  Isabelle Braud,et al.  Flash floods, hydro-geomorphic response and risk management , 2016 .

[20]  J. Pederson,et al.  Geologic versus wildfire controls on hillslope processes and debris flow initiation in the Green River canyons of Dinosaur National Monument , 2006 .

[21]  Emmanouil N. Anagnostou,et al.  Flash floods: Observations and analysis of hydro-meteorological controls , 2010 .

[22]  Eric Gaume,et al.  Hydrological analysis of a flash flood across a climatic and geologic gradient: The September 18, 2007 event in Western Slovenia , 2010 .

[23]  E. Ortiz,et al.  Using post-flood surveys and geomorphologic mapping to evaluate hydrological and hydraulic models: The flash flood of the Girona River (Spain) in 2007 , 2016 .

[24]  Ellen Wohl,et al.  Channel geometry of mountain streams in New Zealand , 2005 .

[25]  Rex L. Baum,et al.  Estimating the timing and location of shallow rainfall‐induced landslides using a model for transient, unsaturated infiltration , 2010 .

[26]  M. Stoffel,et al.  Large wood clogging during floods in a gravel‐bed river: the Długopole bridge in the Czarny Dunajec River, Poland , 2017 .

[27]  R. Mantilla,et al.  Classical and generalized Horton laws for peak flows in rainfall-runoff events. , 2015, Chaos.

[28]  V. Gupta,et al.  Emergence of statistical scaling in floods on channel networks from complex runoff dynamics , 2004 .

[29]  M. Borga,et al.  Hydrometeorological Characterization of a Flash Flood Associated with Major Geomorphic Effects: Assessment of Peak Discharge Uncertainties and Analysis of the Runoff Response , 2016 .

[30]  M. Borga,et al.  Comprehensive post‐event survey of a flash flood in Western Slovenia: observation strategy and lessons learned , 2009 .

[31]  Marwan A. Hassan,et al.  Debris flow initiation and sediment recharge in gullies , 2009 .

[32]  Andrea Petroselli,et al.  Green‐Ampt Curve‐Number mixed procedure as an empirical tool for rainfall–runoff modelling in small and ungauged basins , 2013 .

[33]  F. Guzzetti,et al.  Landslide inventory maps: New tools for an old problem , 2012 .

[34]  Witold F. Krajewski,et al.  Connecting the power-law scaling structure of peak-discharges to spatially variable rainfall and catchment physical properties , 2014 .

[35]  Dawei Han,et al.  Real‐time monitoring of weather radar antenna pointing using digital terrain elevation and a Bayes clutter classifier , 2009 .

[36]  Nadav Peleg,et al.  Radar subpixel-scale rainfall variability and uncertainty: lessons learned from observations of a dense rain-gauge network , 2013 .

[37]  Vincenzo D'Agostino,et al.  Bankfull width and morphological units in an alpine stream of the dolomites (Northern Italy) , 2007 .

[38]  M. Borga,et al.  Estimation of debris flow triggering rainfall: Influence of rain gauge density and interpolation methods , 2015 .

[39]  Marco Borga,et al.  USE OF DIGITAL ELEVATION MODEL DATA FOR THE DERIVATION OF THE GEOMORPHOLOGICAL INSTANTANEOUS UNIT HYDROGRAPH , 1997 .

[40]  Michele Larcher,et al.  Rheological stratification in experimental free-surface flows of granular–liquid mixtures , 2005, Journal of Fluid Mechanics.

[41]  Alessandro Simoni,et al.  Experimental evidences and numerical modelling of debris flow initiated by channel runoff , 2005 .

[42]  Marco Borga,et al.  Controls on event runoff coefficients in the eastern Italian Alps. , 2009 .

[43]  Witold F. Krajewski,et al.  Radar for hydrology: unfulfilled promise or unrecognized potential? , 2013 .

[44]  Eric Gaume,et al.  Post‐flood field investigations in upland catchments after major flash floods: proposal of a methodology and illustrations , 2008 .

[45]  Georges-Marie Saulnier,et al.  Hydrologic Visibility of Weather Radar Systems Operating in Mountainous Regions: Case Study for the Ardèche Catchment (France) , 2002 .

[46]  M. Jakob,et al.  Hydrogeomorphic response to extreme rainfall in headwater systems: Flash floods and debris flows , 2014 .

[47]  L. B. Leopold,et al.  Water In Environmental Planning , 1978 .

[48]  Shaun Lovejoy,et al.  Influence of small scale rainfall variability on standard comparison tools between radar and rain gauge data , 2014 .

[49]  Leonardo Noto,et al.  Physically-based and distributed approach to analyze rainfall-triggered landslides at watershed scale , 2009 .

[50]  Dirk Helbing,et al.  Globally networked risks and how to respond , 2013, Nature.

[51]  Emmanouil N. Anagnostou,et al.  Performance evaluation of high-resolution rainfall estimation by X-band dual-polarization radar for flash flood applications in mountainous basins , 2010 .

[52]  J. Smith,et al.  Hydrologic modeling of extreme floods using radar rainfall estimates , 2003 .

[53]  M. Borga,et al.  Hydrometeorological controls and erosive response of an extreme alpine debris flow , 2009 .

[54]  M. Borga,et al.  Characterisation of selected extreme flash floods in Europe and implications for flood risk management , 2010 .

[55]  Mario Aristide Lenzi,et al.  Large wood storage in streams of the Eastern Italian Alps and the relevance of hillslope processes , 2012 .

[56]  Ke Zhang,et al.  Development of a coupled hydrological-geotechnical framework for rainfall-induced landslides prediction , 2016 .

[57]  V. Ponce,et al.  Runoff Curve Number: Has It Reached Maturity? , 1996 .

[58]  A. Simoni,et al.  Runoff of small rocky headwater catchments: Field observations and hydrological modeling , 2016 .

[59]  M. Jaboyedoff,et al.  Headwater sediment dynamics in a debris flow catchment constrained by high-resolution topographic surveys , 2016 .

[60]  J. W. Kean,et al.  Evolution of a natural debris flow: In situ measurements of flow dynamics, video imagery, and terrestrial laser scanning , 2010 .

[61]  Jason W. Kean,et al.  Runoff‐generated debris flows: Observations and modeling of surge initiation, magnitude, and frequency , 2013 .

[62]  G. Griffiths.  Downstream hydraulic geometry and hydraulic similitude , 2003 .

[63]  Wolfgang Schwanghart,et al.  TopoToolbox: A set of Matlab functions for topographic analysis , 2010, Environ. Model. Softw..

[64]  Francesco Napolitano,et al.  Identification and characterization of rainfall events responsible for triggering of debris flows and shallow landslides , 2016 .

[65]  Francesco Comiti,et al.  Large wood recruitment and transport during large floods: A review , 2016 .

[66]  M. Rossi,et al.  The rainfall intensity–duration control of shallow landslides and debris flows: an update , 2008 .

[67]  M. Borga,et al.  Radar rainfall estimation for the post-event analysis of a Slovenian flash-flood case: application of the Mountain Reference Technique at C-band frequency , 2009 .

[68]  Matthias Jakob,et al.  The role of debris supply conditions in predicting debris flow activity , 1999 .