Seminar Abstract

Dilumie Abeysirigunawardena

Thursday, May 29, 2008

BC Ministry of Environment: Extreme storm surge and wind-storm climatology in the south coast of British Columbia

Storm surge is a natural hazard unique to coastal areas. On British Columbia's (BC) coast, storm surges periodically occur in response to extra-tropical cyclones. The objective of this study is to provide a better understanding of the response of extreme storm surge and windstorm climatology to climate variability and change signals in southern coastal BC (Lat. 48° 50°).

The study is primarily based on application of Extreme Value Analysis in the presence of climate covariates on measured extreme water level residuals commonly known as storm surges (Observed Total Water level Predicted Tide) and on extreme directional winds at selected tide gauge and meteorological stations in southern BC.

Results shows spatially consistent increases in the frequency of occurrence of extreme storm surge events associated with Warm ENSO episodes, while more intense extreme windstorms recurrences are indicated during the cold ENSO regime. This indicates an out of phase relationship between extreme storm surges and extreme wind storms in southern coastal BC, suggesting significant other contributions towards extreme residual sealevel events during a warm ENSO regimes (i.e. thermo-steric).

Speaker bio:

Dilumie Abeysirigunawradena has worked with the BC Ministry of Environment as a Climate Impact Researcher since May 2007. Dilumie obtained her B.Sc. in Civil Engineering from the Faculty of engineering University of Peradeniya Sri Lanka and, her Masters of Science degree on Coastal Engineering (with Distinction) from IHE Delft the Netherlands. Currently she is finalizing her PhD at the University of Victoria under the topic Climate Variability and Change Impacts along the BC coastal margins. Her most recent work is for Environment Canada where she developed the storm surge climatology for coastal British Columbia including an investigation on the influence of climate variability and change on storm surge extremes.

Prior to her current employment, Dilumie worked for 7-years as a Coastal Modeling expert for ADB funded Fisheries and Coastal protection projects in Sri Lanka led by the Lanka Hydraulics Institute Sri Lanka, National Institute for Coastal and Marine Management (RIKZ) in the Netherlands, Maunsell Macintyre Consultants, Australia and NIRAS Port Consultants Denmark. Dilumie's research interests and expertise include the analysis of extreme atmospheric and oceanic response to climate variability and change, climate variability and change impact simulations on coastal margins using the comprehensive mathematical modeling tools MIKE 21 and wave transformation modeling in SWAN.