Prediction and Field Measurements of Wave Run-up and Overtopping on a Seawall

Chi-Min Chiu, Yu-Chen Chang, Ching-Jer Huang, Chun-Yuan Lin, Chung-Min Tseng, Jia-Lin Ma, Jong-Hao Wang

Thursday 2 july 2015

12:30 - 12:33h at Europe 2 (level 0)

Themes: (T) Flood risk management and adaptation, (ST) Early warning systems, Poster pitches

Parallel session: Poster pitches: 11K. FloodRisk - Early Warning

Predictions of maximum wave run-up height and overtopping rate are key tasks in early warning for coastal disaster during a typhoon season. This study compares the predicted wave run-up height by using an empirical formula with those obtained from filed measurements. The maximum wave run-up height and the averaged overtopping rate were estimated by using the empirical formula given in Costal Engineering Manual (1992). Estimate of the maximum wave run-up and overtopping rate on the rough, impermeable sloping seawalls requires the input data, such as the actual topography of the coast and the composite beach section, including the slope and roughness of seawall, as well as wave conditions and the water levels. This study adopted the POM and SWAN models to provide 72-hr forecasts of water levels and waves. The electrical conductivity meters were used for monitoring the real-time wave run-up on a seawall. The wave run-up was justified by distinguishing the seawater from the freshwater. The wave run-up on the Zeng-Wen seawall located at Tainan, Taiwan, were recorded during the UTOR, USAGI and TRAMI typhoons in 2013. Comparison of the measured wave run-up height with those obtained from the empirical formula given in Costal Engineering Manual (1992) shows that both are in good agreement. This comparison indicates that the developed real-time wave run-up monitoring system can be deployed on the seawall to detect the wave run-up and overtopping during the typhoon period. Furthermore, the recorded wave run-up data can be used to calibrate the parameters for obtaining a reliable site-dependent formula for wave run-up.