TY  - JOUR
PY  - 2023//
TI  - Debris-flow surges of a very active alpine torrent: a field database
JO  - Natural hazards and earth system sciences
A1  - Lapillonne, Suzanne
A1  - Fontaine, Firmin
A1  - Liebault, Frédéric
A1  - Richefeu, Vincent
A1  - Piton, Guillaume
SP  - 1241
EP  - 1256
VL  - 23
IS  - 4
N2  - This paper presents a methodology to analyse debris flows focusing at the surge scale rather than the full scale of the debris-flow event, as well as its application to a French site. Providing bulk surge features like volume, peak discharge, front height, front velocity and Froude numbers allows for numerical and experimental debris-flow investigations to be designed with narrower physical ranges and thus for deeper scientific questions to be explored. We suggest a method to access such features at the surge scale that can be applied to a wide variety of monitoring stations. Requirements for monitoring stations for the methodology to be applicable include (i) flow height measurements, (ii) a cross-section assumption and (iii) a velocity estimation. Raw data from three monitoring stations on the Réal torrent (drainage area: 2 km2, southeastern France) are used to illustrate an application to 34 surges measured from 2011 to 2020 at three monitoring stations. Volumes of debris-flow surges on the Réal torrent are typically sized at a few thousand cubic metres. The peak flow height of surges ranges from 1 to 2 m. The peak discharge range is around a few dozen cubic metres per second. Finally, we show that Froude numbers of such surges are near critical.<p />  <p>Language: en</p>
LA  - en
SN  - 1561-8633
UR  - http://dx.doi.org/10.5194/nhess-23-1241-2023
ID  - ref1
ER  -