Abstract:
Storm surges are one of the worst coastal marine
hazards in the world. Coastal flooding due to tropical cyclone -
induced storm surges has caused considerable damage and loss
of life in the North Indian Ocean region including in Sri Lanka.
Possible sea level rise is gradual and occurs over a long time
frame. However, extreme weather events can occur at any time
and can have a significant impact on the coast line. This study is
about the estimation of storm surge heights at Colombo
coastline. Sea water levels measured off Colombo Port for 31
years were analyzed using statistical methods to establish the
design storm surge heights with known return periods.
Harmonic analysis based computer program was used to
generate astronomical tide and storm surges were considered as
the difference between sea level and astronomical tide. The
extracted surge data were statistically analyzed by using the
Extreme Event Analysis method. Design sea levels with different
return periods are calculated and presented with the paper. The
storm surge height for 100 year return period was found to be
0.391m and corresponding design sea level height was 0.906 m
relative to mean sea level.
