  This paper presents a new simulator for dynamic modelling of interactions
between flooding and people in crowded areas. The simulator is developed in
FLAMEGPU (a Flexible Large scale Agent-based Modelling Environment for the
GPU), which allows to model multiple agent interactions while benefitting from
the speed-up of GPUs. Flooding variables including terrain data are represented
by a hydrodynamic Agent-Based Model (ABM) that is based on a non-sequential
implementation of a robust Finite Volume (FV) solver of the Shallow Water
Equations (SWEs). People movements are represented by a pedestrian ABM adopting
force-based walking rules. The hydrodynamic ABM is coupled to the pedestrian
ABM according to risk-to-life thresholds reported by the UK Environment Agency
(EA). A hypothetical case study of a crowded shopping centre is proposed and
used to assess the dynamic coupling ability of the simulator. Flooding into the
shopping centre is induced based on realistic inflow conditions, and the
simulator is applied considering two scenarios: evacuation without advanced
warning and intervention with an advanced warning of 12 hours. Results show
that the simulator can produce detailed statistics of spatiotemporal people
states during evacuation, and is useful to plan safe and effective people
intervention to deploy a sandbag-based temporary barriers.
