Living with Supertyphoons
Posted by butalidnl on 10 January 2015
The Philippines has to accept the fact that a supertyphoon will hit the country every year, sometime between November and mid-December. It also has to prepare for it.
In the last 4 years, a supertyphoon has hit the country:
2011 – Sendong – December 15 -17
2012 – Pablo – December 2 – 9
2013 – Yolanda – November 7 – 8
2014 – Ruby – December 6 – 10
We might also count Ondoy (September 23-30, 2009) as a supertyphoon. It didn’t have supertyphoon winds, but dumped lots of rain. It did come rather early.
This is unlikely to be a coincidence, or a case of bad luck. There is a reason why supertyphoons happen at this time. It has something to do with the huge amount of heat stored in the Pacific Ocean. In the earlier part of the rainy season, typhoons form in the Pacific Ocean, but they mostly skirt the Philippines, and some of them hit northern Luzon. Towards the end of the year, a high pressure area forms over China, which is also the source of the amihan (the northwest monsoon). But there is still heat left over in the Pacific which could still form storms. A typhoon would then form just north of the equator (typhoons forming south of the equator go southwards) using this reservoir of heat. The combination of this excess heat, the low lattitude in which the storm starts, and the amihan blowing from China, combine to form this typhoon.. The typhoon then heads west northwest towards the Philippines; rapidly gains strength, and becomes a supertyphoon. The amihan winds prevents it from heading north, and thus it makes its way to Samar or Mindanao.
Ruby hit too far north and moved too slow over the country when compared to the other supertyphoons. This meant that the amihan winds, and Luzon’s mountains (e.g. Sierra Madre) were able to slow it down and promptly degrade it..
Supertyphoons form because of excess heat that is left in the Western Pacific at the end of the year. This area is warmer than it used to be.
The excess heat theory may also explain why Typhoon Ruby was not as strong as expected. Scientists have noted an El Nino effect in 2014, which usually means that the Eastern Pacific (i.e. US west coast and western Latin America) will get more rain, while the Western Pacific less rain, because currents bring heat eastwards. If this is the case, there was less excess heat to power up Typhoon Ruby, as compared to previous years. It also means that when the El Nino effect wears out, our supertyphoons may get to be as strong as Yolanda was.
But there seemed to have been some excess heat left over in the area just southeast of Mindanao even after Ruby, And this gave birth to Typhoon Seniang, which hit the country on 29 to 31 December 2014. While Seniang was a weak tropical storm (with maximum winds of 95 kilometers per hour), it brought a lot of rains, And it was deadlier than Supertyphoon Ruby; Seniang killed 65 people, while Ruby 19.
All this means that the national government, LGUs, NGOs, even businesses need to prepare for this end-of-year supertyphoon. All of the Visayas and most of Mindanao can potentially be hit by these supertyphoons. Buildings should be made to withstand winds exceeding 300 kilometers/hour. Of particular importance would be evacuation centers (sports stadiums, schools, churches), relief command centers (often these would be city halls), and food storage buildings. These should all be sturdy, and located away from areas vulnerable to floods, storm surges and landslides. While it may take years to strengthen all residential housing, building codes should already be upgraded.
The national government should give more powers to the National Disaster Risk Reduction and Management Council (NDRRMC) by including typhoon rehabilitation work in its tasks, in addition to typhoon mitigation. This was the recommendation of Senator Ping Lacson, head of the Office of the Presidential Assistant on Rehabilitation and Recovery (OPARR) which was tasked to coordinate the rehabilitation work for typhoon Yolanda. Lacson suggests to fold in OPARR’s tasks into an expanded NDRRMC. This makes sense especially with the insight that supertyphoons are going to be a regular occurence.
Other adjustments should be made e.g. ‘rescheduling’ the harvest season so that it ends in October, strictly banning buildings in vulnerable areas, and upgrading LGU disaster response capabilities. Laws should be passed allowing LGUs to commandeer food stocks and other supplies in case of disaster, and to order mandatory evacuation of vulnerable areas in case a supertyphoon approaches.
There would be another supertyphoon that will hit the country in November-December 2015. While we cannot prevent it, we can prepare for it as well as we can.