ASSESSMENT ON TSUNAMI HAZARD LEVEL AND ITS IMPACT TO PORT INFRASTRUCTURES IN INDONESIA (STUDY CASE: PULAU BAAI PORT, BENGKULU)

• Main Author: Kirana Fidari Pratopo, Auzora
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25938
• Institution: Institut Teknologi Bandung

Indonesia is an archipelago that consists of ocean on a set of highly active tectonic plates, thus putting it on a high risk of tsunami. As a country with ocean as the largest part of its territory, it makes the ocean an important aspect of various development areas in Indonesia. Sea transportation is one example among the many industries that depend on Indonesia’s ocean. The industry heavily relies on ports and its infrastructure, but it is prone to coastal disasters like tsunami. Using a previously generated model, this Final Project sorted tsunami hazard levels of ports in Indonesia. The result showed that Pulau Baai Port in Bengkulu has the highest tsunami hazard level among others. Facing Indian Ocean directly, this port with its sailing and freight activities is at risk of tsunami at 6 meters in height. Based on that information, a tsunami numerical simulation was conducted using 3 hypothetical scenarios. The scenarios are Scenario 1 with Mw=7.9, Scenario 2 with Mw=8.4, and Scenario 3 with Mw=8.9. COMCOT software v1.7 was used to run the simulation with nested grid method at a 7200 seconds duration. The simulation resulted in time arrival tsunami at the port within range of 23.81 – 55.86 minutes in Scenario 1, 23.05 – 51.4 minutes in Scenario 2, and 20.93- 45.95 minutes in Scenario 3. Maximum level of heights are 8.86 metres, 9.4 metres, and 17.1 metres for Scenario 1, Scenario 2, and Scenario 3 respectively. Scenario 3 showed the highest level of maximum flowdepth compared to the other scenarios, that is 6.8 metres, while Scenario 2 and Scenario 1 resulted in 6.022 metres and 3.49 metres of maximum flowdepth. In each scenarios, the flowdepth occurred at a different surface area and height, but in Scenario 3, on the other hand, the port was entirely submerged at 0,1-3 metres height. From the results of Scenario 3, an analysis on the damage of the port and its infrastructure was conducted. The analysis showed that tsunami in Pulau Baai Port with flowdepth at a 3 metres maximum can wash away debris like logs, poles, passenger vehicles, containers, and fishing vessels at maximum 5 ton capacity. Tsunami with current velocity of 18,51 m/s can cause a major damage on the port as well.