final_program_abstracts[1]

11 IMSC Session Program
Extreme value prediction of typhoon events – Models and
applications
Thursday - Parallel Session 7
Defu Liu, Huajun Li, Liang Pang and Fengqing Wang
Ocean University of China, Qingdao, China
Since 1972 typhoon No.12 induced extraordinary storm surge attacked Dalian port in
Bohai sea of China, causing severe damage in this port, and 1975 typhoon Nina
induced storm inundation led to 25,000 death and effected 12,000,000 people, we
found that traditional extrapolation by asymptotic distributions from annual maxima
data sampling method can not determine the design return period for such
extraordinary typhoon events. By compounding a discrete distribution (typhoon
frequency) and a continuous extreme distribution of typhoon events, the Compound
Extreme Value Distribution (CEVD) was derived and published in US at 1980 and
CEVD used to predict hurricane characteristics along Gulf of Mexico and Atlantic
coasts in 1982. The predicted results by CEVD were higher than NOAA proposed
SPH and PMH in West and East Florida regions, and they are close to the 2005
Katrina and Rita hurricane characteristics.
During the past years CEVD has been developed into Multivariate Compound
Extreme Value Distribution (MCEVD) and applied to prediction of typhoon induced
sea hazards for coastal, offshore structures and estuarine cities. Both of CEVD and
MCEVD have advantages: instead of traditional annual maximum data sampling, the
typhoon process maximum data sampling is used, and typhoon frequency involved in
the model.
Based on the MCEVD, the Double Layer Nested Multi-objective Probability
Model(DLNMPM) is proposed in which the joint probability prediction of different
typhoon characteristics are taken as the first layer and typhoon induced disaster
factors (such as strong wind, storm surge, huge wave, heavy rain, inundation,
landslide and so on) are taken as the second layer. This model was adopted by the
Office of State Flood Control and Drought Relief Headquarters of P.R. of China for
typhoon disaster prediction, prevention and mitigation.
Proposed models are successfully used to study on the New Orleans and Shanghai
prevention criteria; joint probability study of combined extreme sea environmental
loads criteria and deck clearance for fixed platform; long term prediction of
sedimentation for sea port and waterway; reliability analysis and risk assessment for
some important coastal defense structures by MCEVD.
Abstracts 248