A high-performance coupled human and natural systems (CHANS) modelling framework for flood risk assessment and emergency management

This doctoral thesis advances the field of flood risk modelling, assessment and management through the development and application of a novel high-performance Coupled Human And Natural Systems (CHANS) modelling framework, helping address the increasing risk of urban flooding due to climate change, urban expansion, and infrastructure deficits. Central to this research is the integration of complex dynamic human behaviours in flood risk assessment and emergency management strategies.

The thesis is structured around three key studies, each targeting a different aspect of flood risk management. The first study explores household behaviours during compound flooding events by introducing a CHANS framework that integrates a hydrodynamic model with the agent-based model for real-time, high-resolution simulation of flood dynamics and household level human responses. It showcases the model’s effectiveness in the Eden Catchment, England, emphasising the importance of understanding human behaviours in flood management. The second study shifts the focus to technological and infrastructural responses to fluvial flooding in developed regions, through further developing and applying the CHANS model to evaluate emergency protection measures during the 2015 Desmond flood in Carlisle, UK. This illustrates how human actions and flooding processes interact dynamically, informing decision-making in emergency management. Lastly, the third study examines flood risk management in an less-developed region, introducing mobile pumping strategies for pluvial flood mitigation optimised via Reinforcement Learning (RL) within the CHANS framework. Applied in the Ninh Kieu District of the Can Tho City, Vietnam, this approach demonstrates an effective pluvial flood risk reduction approaching through mobile pumping, highlighting the framework’s adaptability and potential for enhancing urban flood resilience.

Overall, this research advocates for a multifaceted flood management approach, directly integrating the physical process of flooding with human and social dynamics, and provides an innovative and useful tool towards the exploration and development of more effective, adaptable, and sustainable urban flood risk management solutions.