Brian Tucker (1975 SIO/IGPP PhD, now at GeoHazards International, Menlo Park CA)
Prototype Tsunami Evacuation Park in Padang, West Sumatra, Indonesia
Padang, Indonesia, a city of some 900,000 people, half of whom live close to the coast and within a five-meter elevation above sea level, has one of the highest tsunami risks in the world due to its close offshore thrust-fault seismic hazard, flat terrain and dense population. There is a high probability that a tsunami will strike the shores of Padang, flooding half of the area of the city, anytime during the next 30 years. If that tsunami occurred today, several hundred thousand people would die, as they could not reach safe ground in the ~30 minute interval between the earthquake’s occurrence and the tsunami’s arrival. Padang’s needs have been amply demonstrated: after earthquakes in 2007, 2009, 2011 and 2012, citizens, thinking that those earthquakes might have triggered a tsunami, tried to evacuate in cars and motorbikes, and created traffic jams that prevented them from reaching safe ground in 30 minutes.
Since 2008, GeoHazards International (GHI) and Stanford University have studied a range of options for improving this situation, including ways to accelerate evacuation to high ground with pedestrian bridges and widened roads, and means of “vertical” evacuation in multi-story buildings, mosques, pedestrian overpasses, and Tsunami Evacuation Parks (TEPs), which are man-made hills with recreation facilities on top. TEPs proved most practical and cost-effective for Padang, given the available budget, technology and time.
GHI has acquired permission to build a prototype TEP in the northern part of Padang that would accommodate about 25,000 people during the time of a tsunami, and would cost about $2.4 million to construct, amounting to a cost-per-life-saved of ~US$100, far lower than the per capita cost of the other options. The cost of replication should be less. GHI has helped form an Indonesian foundation that has raised to-date $500,000 toward the construction cost.
This interdisciplinary, international effort demonstrated that TEPs offer the best option for Padang because they have the potential to save thousands of lives, are relatively simple to build and maintain, invite everyday recreational use by the community, and have attracted strong Indonesian government support as a possible means to manage the country’s tsunami risk.