A conceptual model of people’s vulnerability to flood

Hydraulic risk maps provide the baseline for land use and emergency planning. Accordingly,
they should convey clear information on the potential physical implications of the different hazards to the
stakeholders. This paper presents a vulnerability criterion focused on human stability in a flow specifically
devised for rapidly evolving floods where life, before than economic values, might be threatened. The
human body is conceptualized as a set of cylinders and its stability to slipping and toppling is assessed by
forces and moments equilibrium. Moreover, a depth threshold to consider drowning is assumed. In order to
widen its scope of application, the model takes the destabilizing effect of local slope (so far disregarded in
the literature) and fluid density into account. The resulting vulnerability classification could be naturally sub-
divided in three levels (low, medium, and high) that are limited by two stability curves for children and
adults, respectively. In comparison with the most advanced literature conceptual approaches, the proposed
model is weakly parameterized and the computed thresholds fit better the available experimental data sets.
A code that implements the proposed algorithm is provided.