Pluvial flood modeling for coastal areas under future climate change – A case study for Prince Edward Island, Canada

It has been increasingly understood that pluvial flooding poses a substantial risk to numerous communities across the globe. This is especially relevant for the Canadian province of Prince Edward Island (PEI), which is susceptible to a compound flood consisting of both inland and coastal flooding. Despite various studies, a comprehensive pluvial flood model still lacks that addresses the complex interplay of compound floods. Therefore, this research aims to bridge the gap in flood mitigation by developing a pluvial flood model for PEI’s coastal communities. The Intensity-Duration-Frequency (IDF) curves under current and future climatic conditions were used to portray rainfall intensity over the study area corresponding to 10-year, 25-year, 50-year, and 100-year return periods. In addition, a hydraulic model (HEC-RAS 2D) was used to drive pluvial flood maps based on two configurations, including detailed flood maps for major municipalities and an island-wide level. The validated results showed consistency in model simulation when compared to observations. The high-resolution flood maps produced by this study can support the development of flood mitigation and adaptation strategies in PEI and other parts of the world.