High-Resolution Flood Risk and Impact Modeling

Floods are the most frequent natural hazard globally, and flood-induced losses are expected to grow with future climate and land-use changes. In this context, quantitative flood-risk analysis models are critical to understanding, planning for and promoting resilient cities and communities, particularly in the face of climate change and sea-level rise. Such models have been crucial for underpinning flood mitigation planning by water management agencies (e.g. PUB), as well as the catastrophe insurance sector (e.g. flood insurance programs). Yet flooding events continue to regularly overwhelm protective infrastructure and insurance reserves because of gaps and inaccuracies in flood risk analysis models. In particular, while most research and development in flood risk analysis has focused on the flood hazard component of risk analysis, little attention has been placed on the consequences component (exposure and vulnerability) or on the link between the geophysical process of flooding and the statistical models used to represent them in risk analyses. This study aims to address these gaps through three main objectives (1) the development of new techniques for high-resolution flood exposure making use of street-view imagery analysis techniques, (2) the development of building-component-level damage models to capture complexities of flood damage dynamics more accurately than current building-level damage models, and (3) the use of spatial statistics to account for missing drivers of flood damage that are not captured in hydrodynamic process-models of flood hazard. These aims are linked, and collectively will enable the better identification and characterization of assets at risk (aim 1), better modelling of their vulnerability to flooding (aim 2), and with reduced bias through the use of statistical correction (aim 3). The results of this project will contribute to better understanding of floods and better quantifying their impacts on society. This will produce significant benefits to the flood management, planning and insurance industries, and is particularly relevant to Singapore and other cities facing the challenge of increasing flood impacts driven by climate change and sea-level rise.