Wednesday, March 2, 2016

Bigger Perspective on Fiji's TC Winston and a Lesson on Resilient Construction

Tropical Cyclone Winston ravaged the islands of Fiji 11 days ago, pummeling the islands with category-5 winds. The death toll from this storm has reached 42, according to a Monday blog post from Jeff Masters and Bob Henson. Their blog post also provides early estimates of economic losses.

NOAA satellite image of category-5 Tropical Cyclone Winston bearing down on Fiji

While this is the deadliest cyclone in the modern history of the South Pacific, a cyclone more than 400 years ago killed 1000-2000 people in the Cook Islands (De Scally 2008), presumably from a massive storm surge. While comparison to the Cook Islands cyclone, which struck a long time ago, does not make it any easier for those recovering from Winston, it does provide perspective that human losses in the region have been even greater than this before. Technological advances, and the excellent work by the Fijian Government to warn people of Winston's approach, likely reduced potential fatalities considerably.

In addition to loss of life and immediate economic losses, cyclones in this region often inflict long-term impacts related to loss of food and water supplies, as it is difficult for islands to replenish these resources after a salt-water inundation (Needham et al. 2015).

Winston's category-5 winds pushed surge and high waves onto the Fijian Islands on Sat Feb 20.

The power of social media to connect people after a disaster became evident after I posted photos last week providing evidence of a 10 ft (3 m) storm surge in coastal Fiji. I implored blog readers to help identify the locations of the photos, which would enable us to get an early read of the surge inundation.

I posted this photo last week, which provided evidence of a 10 ft (3 m) storm surge in Fiji.
Original Photo: NZ Defence Force

Soon after my post, I received a message from Brooke Langston, a former Peace Corps volunteer in the Ministry of Fijian Affairs from 2013-2014. Brooke made contact with Fijians who were familiar with the locations of the photos, and I soon found out that the photos with the high water marks were from a village on the island of Vanua Balavu, the third largest island in the Lau archipelago.

 Satellite Image: Himawari-8 satellite
Graphical edits: Hal Needham

The center of Winston's circulation tracked close to Vanua Balavu, and the satellite image above shows that Winston's eyewall was pummeling the island, with vicious winds from the southeast when the photo was taken (TC circulation in Southern Hemisphere is clockwise).

John O’Leary (@OLjohnel) provided a link to a Fijian government site that provided lat and lon values of many air photos (see @FijiRepublic). Through these sources, we are able to form a better picture of storm surge inundation.

Despite Winston's catastrophic losses, not all news coming from Fiji is bad.  A Radio Australia article emerged discussing how the 164 homes built by Peter Drysdale in Koroipita survived the cyclone with little damage. According to Drysdale,  the use of steel strapping coils and roofing screws provide stronger construction to endure cyclonic winds.

Peter Drysdale's 164 homes that survived Tropical Cyclone Winston with minimal damage.
Photo courtesy Joe Yaya and posted to Radio Australia Webpage.

We can read more about the fascinating story of how Drysdale built simple, but sturdy, homes for many of Fiji’s poorest in this story by the Australian Broadcasting CorporationDrysdale claims that these buildings can be constructed in five days and only cost $13,000 Australian dollars ($9,414 U.S. dollars) to construct ($13,000 was quote from most recent article; the article from 2015 quoted $12,000....but hey, inflation is real).

Peter Drysdale supervised the construction of 164 houses that were built for many of Fiji's poorest people. These structures performed very well in Tropical Cyclone Winston.
Photo Courtesy Australian Broadcasting Corporation.

This story provides a few important take-home messages. One lesson learned is that adapting construction for violent cyclones and the bigger picture of climate change does not have to be cost prohibitive. Another lesson is that it is clear Drysdale constructed these homes to withstand powerful cyclones, and when they were tested, they stood.

This should cause us to ask if the homes in our coastal communities are constructed with powerful cyclones in mind, or if we consider such events too rare to consider. Such questions will become increasingly important due to the changing climate along our coasts.

The 2015 ABC article  reveals that many people interested in Peter's homes are climate change refugees moving from the country to the city, or even coming from other island nations, like Kiribati. Clearly this innovative project should stand as a model of a practical project to improve coastal resiliency in areas prone to tropical cyclone/ hurricane strikes.


De Scally, F. A. (2008), Historical tropical cyclone activity and impacts in the Cook Islands, Pac. Sci., 62, 443–459.

Needham, H.F., B.D. Keim, and D. Sathiaraj, 2015: A Review of Tropical Cyclone-Generated Storm Surges: Global Data Sources, Observations and Impacts. Reviews of Geophysics, 53, 2, 545-591.

No comments:

Post a Comment