A flash flood hazard assessment in dry valleys (northern France) by cellular automata modelling

Abstract

This paper presents an application of a cellular automaton-based run-off model (RUICELLS) to a series of small dry valleys in the Seine-Maritime department, northern France, to better assess their susceptibility to flash flood. These muddy floods shortly follow high rainfall (50-100 mm in less than 6 h) and occur in very small areas (\20 km 2 ). A surge generally rushes down through the main valley just a few minutes after rains have peaked. Previous events (n = 69, in the period 1983-2005) have occasionally threatened human lives and have caused significant damage to property and infrastructure. Nonetheless, given the variation among the valleys and the infrequency of events, these floods have not been numerous enough to permit a statistical analysis. Instead, we numerically simulate the possible future flash floods using RUICELLS, a cellular automaton model driven by a set of three deterministic hydrological rules. Simulations have been conducted for 148 basins, each subject to 16 different rainfall scenarios (2.368 simulations in total) to (1) estimate the peak flow discharges (Q), the specific peak flows (Q s ), and the lag times (T) of the flash floods and (2) 123Nat Hazards (2015) 75:2905-2929 DOI 10.1007/s11069-014-1470 warnings and increased vigilance. Our simulations indicate that the number of basins susceptible to flash flooding greatly increases with the higher rainfall intensity, the distribution of sensitive crops (sugar beet, corn, maize, and flax) and the basin morphology. Several small basins could also induce by convergence a bigger flood in the downstream humid valleys. The location of the highest simulated discharges is aligned with observed events, and this comparison provides an evaluation of the modelling performance and of the credibility of the results.

Towards Regional Scale Stormwater Flood Management Strategies through Rapid Preliminary Intervention Screening

“…Early examples of these models were applied to simulate fluvial dynamics [47]. The approach has been applied to stormwater flood dynamics across flood plains [48][49][50][51][52]. Recent approaches have refined this application towards detailed simulation of urban environments, although so far this has been undertaken at limited scale [25,[53][54][55].…”

“…Water 2021, 13, x FOR PEER REVIEW 4 of 21 plains [48][49][50][51][52]. Recent approaches have refined this application towards detailed simulation of urban environments, although so far this has been undertaken at limited scale [25,[53][54][55].…”

Description and evaluation of a surface runoff susceptibility mapping method

“…The Lézarde catchment (210 km²), located between the English Channel and the Seine river, is wellknown for being subject to flooding predominantly generated by surface runoff Douvinet et al, 2014;Le Gouee et al, 2010). The catchment morphology is composed of large plateaux and narrow valleys ( Figure 2).…”

Use of post-event surveys of impacts on railways for the evaluation of the IRIP method for surface runoff mapping

“…To manage these risks, it is essential to well understand the phenomenon and to know where it is the most susceptible to occur. Several methods allow the mapping of surface runoff, such as STREAM [6], SCALES [7], RuiCells [8], EXZECO [9] or Erruisoll [10]. In this paper, we focus on the IRIP method [11]- [14] -Indicator of Intense Pluvial Runoff (French Acronym) -.…”