Lean Santos of Devex provides interesting insight into the challenges of communicating storm surge predictions to coastal populations in article #1 below.
Christopher Bodeen provides insights into the mindset of locals as this event unfolded, as well as some fascinating insights into evacuation options for people who live in a nation of many islands. See article #2 below.
He also provided a quote that may best summarize the need for education. He quotes senior presidential aide Rene Alemendras, who said, "I was talking to the people of Tacloban....They said 'we were ready for the wind. We were not ready for the water.'
Many people in the Philippines were not prepared for Haiyan's massive storm surge. The coastline of the Philippines contains many gulfs, bays and inlets, which create localized surge heights, making education efforts challenging in this region. Image: Associated Press
Many people have been asking me how it is possible that the people of the Philippines were not ready for this storm surge event, when they experience so many typhoons (hurricanes). Although such issues are complex, involving many physical and societal variables, we must remember a few things about this surge event and storm surge in the Philippines.
1. The magnitude of this catastrophe was truly extraordinary.
As explained on previous blog posts, it is thought that Haiyan produced stronger wind speeds at landfall than any tropical cyclone in world history. Also, the surge height appears to have exceeded 6 meters, which would place it close to the 7.3-meter storm surge of 1897 on Samar, Philippines. The 1897 event was the largest surge level in the modern history of East Asia.
2. Storm surge inundation in the Philippines tends to be very localized.
The coastal shape of the Philippines contains many gulfs, bays and inlets, as the Philippines are really comprised of numerous large and small islands. Storm surge tends to pile up in bays and inlets that are exposed to strong onshore winds. However, the area of the highest storm surge is often quite localized, and dependent upon the track of the storm.
Therefore, many typhoons may impact a given location over a period of several decades, but perhaps only one typhoon will generate a massive storm surge at that place, because the track needs to be just right to pile up surge along the coast. Such localized effects make storm surge education very difficult, because slight changes in storm tracks over the Philippines will often produce vast differences in coastal flooding patterns.
Hurricane Ike generated a widespread surge along the U.S. Gulf Coast in 2008. Much of Texas and South Louisiana would have been flooded even if Ike's track slightly shifted, because most of the coast is open and exposed to storm surge. In contrast, the coastal shape along the islands of the Philippines create very localized surge heights. Image: SCIPP/ SURGEDAT (Hal Needham).
In general, broader bodies of water with less islands tend to have less localized surge events, making education somewhat easier, because surges tend to be widespread. Take South Louisiana, for example. Most of the coastline is flat and exposed to the Gulf of Mexico. In 2008, Hurricane Ike made landfall in Texas, but generated a massive surge along the Louisiana Coast. However, if the track of Ike changed by 100 km (62 miles), most of South Louisiana would have still experienced a massive storm surge. In contrast, if Typhoon Haiyan's track had changed by 100 km, it is likely that the surge pattern would have been quite different, because the intricate shapes of the islands help generate different surge heights when the storm track changes.
The localized nature of surge in the Philippines may help explain why many people were taken off guard. Such people may be surprised to find out that future tropical cyclones with slightly different tracks may produce very different storm surge levels in hard-hit areas like Tacloban. Education efforts may help people to realize the causes of storm surge, as well as localized patterns in their region.