Optimization of Tsunami and Earthquake Awareness Through Digital Mapping Using a Decision Support System with Simple Additive Weighting (SAW) in Padang City

Abstract

Padang is a city that is prone to earthquakes and tsunamis due to its location between the India and Asia plates
on the west coast and being crossed by the Great Sumatran fault. The Padang coastal region is a strong source of
earthquakes and tsunamis. Despite having experienced earthquakes in 2006, 2007, and 2009, Padang still faces
difficulties in managing tsunami evacuation because of the lack of infrastructure and straight roads from the coast to
higher ground. The presence of rivers in Padang causes the tsunami waves to be concentrated within a 200-meter radius
and the evacuation routes are hindered by the presence of bridges that are not durable against tsunamis and earthquakes.
Additionally, traffic congestion after an earthquake exacerbates the evacuation problems. This study aims to map the risk
and potential of earthquakes and tsunamis in Padang 3 KM from the coast by comparing population and building data
with the availability of shelters. The Simple Additive Weighting (SAW) method, as part of Geographic Information
System, is used to analyze demographic data and shelter locations. The results show that Koto Tangah is the area with the
highest risk level for earthquakes and tsunamis.