A comparative analysis of hydrodynamic and GIS modelling for coastal flood Vulnerability assessment to determine the best approach for guiding coastal management.

  • Avidesh Seenath (Speaker)

Activity: Talk or presentationOral presentation


Co-authored with Matthew Wilson and Keith Miller

With rising sea levels under climate change, the probability of intense coastal floods from storm surges will increase for low lying coastal communities. Therefore, it is imperative to conduct Coastal Flood Vulnerability Assessments (CFVA), as a guide, to implement measures to reduce susceptibility. In this paper, hydrodynamic modelling is compared with the use of a Geographic Information System (GIS) to determine the best approach for guiding coastal management using Pigeon Point, south-west Tobago, as a case study. A two-dimensional hydrodynamic flood model was created from bathymetry, elevation, current and future projected mean sea level, and tidal data using both the LISFLOOD-FP and TELEMAC-2D code to assess the present and future impact of storm surges, of different magnitudes, on coastal flood extent at Pigeon Point. Using the same data on topography and bathymetry, a coastal digital elevation model of Pigeon Point was developed and incorporated into a GIS to perform the same assessment using the exact scenarios applied in the hydrodynamic modelling. Average results indicate that flood extent at Pigeon Point will significantly increase under future projected sea level conditions when compared to current conditions in each surge scenario. A comparative analysis of all results revealed that GIS modelling appeared to over predict flood extent while minor deviations in flood output was acquired from modelling using LISFLOOD-FP and TELEMAC-2D. We conclude that GIS modelling be used as a generalized indicator of potential flooding while hydrodynamic modelling be applied for a more accurate CFVA to better support coastal management decisions.
Period16 Jun 2014
Event titleCoastal Zone Canada
Event typeConference
LocationHalifax, Canada, Nova ScotiaShow on map