Discussions on disaster risk reduction for Padang City against tsunami by the seawall

Abstract

The 30 September 2009 Padang Pariaman (or West Sumatera Earthquake) (M = 7.6 USGS) has caused severe damages of buildings and infrastructures and fatalities. Many of the buildings failed may be due to the low quality of the structures or due to that most buildings were designed Indonesian code SNI 1726-2002, and many of them failed because of the occurrence of liquefaction causing foundation failures. However, a future earthquake could have been even more severe and causes a tsunami, a reality which we shall consider, especially because Padang City is located facing directly to the ocean. Based on the occurrence and experience in Banda Aceh, Padang City has similar risk and yet very limited barrier and lack of evacuation system. For evaluation of this issue, a team of Universitas Katolik Parahyangan conducted a preliminary study on the condition of Padang City and discuss some alternatives to be considered by the government or authority. Methods of research are based on a literature study and collected data for analysis. Options are discussed and conclusions are derived. This paper discusses the important lessons from Banda Aceh failures related to the tsunami, and method to reduce the disaster risk for Padang City by Tsunami Seawall. The purpose of this study is to discuss the risk of the tsunami at Padang City, the preparedness and local condition, and alternative actions to be carried out. There has been pro and cons for Seawall, but the study concluded that due to the fact that tsunami would reach the city within 15-30 minutes after the earthquake and condition of low lying elevation of the Padang City, the use of Seawall for city safety is worth to be considered.