Wave distribution and proposed seawall design around Tanjung Emas Port, Semarang

Civil Engineering Department, Vocational School, Universitas Gadjah Mada, Jl. Yacaranda Sekip Unit IV, Yogyakarta, Indonesia

^* Corresponding author: wakhidatik@ugm.ac.id

Abstract

On May 23^rd, 2022, an extreme coastal event occurred around the northern coast of Java. This event had caused the collapsed of several seawall segments around Tanjung Emas Port, Semarang. Combined with wave overtopping, it led to severe flooding and economic damages to the port operation. Responding to the event, this research aimed to characterize the hydrodynamic condition around the port and proposed a seawall design. The research was done through field observation, wave climate characterization, and numerical simulation. The field observation confirmed the extent of the damage and wave condition around the harbour. The wave climate study, based on a global wave reanalysis data, confirmed that the offshore wave height could reach 3 m during high wave season, with wave period of 4 – 6 seconds coming from the northwest. The tidal range is up to 1 m with highest astronomical tide (HAT) is at +0.65 MSL. The extreme value analysis gave a 3.7 meter of offshore design wave height for 100-year return period or up to 1.7 meters wave height nearshore. The proposed seawall crest elevation is at least at +3.40 meters above the mean sea level to avoid overtopping, which is 1.1 m higher than the existing seawall.