Cautionary signal

Don’t be lulled just yet into El Niño drought being downgraded  by the Department of Science and Technology.  The peak is just ahead. Beefed-up  sustained  response for rougher threats  in the years ahead is more urgent than ever.

That  cautionary notes comes from hydrologist Pedro Walpole who heads the Institute of Environmental Science for Social Change  based in Ateneo  Loyola Heights. Walpole is  a Jesuit priest.
Many  thought the threat was over. Not so.  Although weaker, its effects here will  peak next month. A fading El Niño can still affect  harvests of small farmers who constitute an overwhelming majority.  Many  have no fall back source for their next meal.

We understand better now the time lag between when El Niño is declared in mid-Pacific and when it slams in,  say mid-Mindanao’s  Bukidnon, writes Dr. Wendy Clavano of  Environmental Science for Social Change.  That  lag  comes  roughly  to  197 days.

Analytical tools, like standardized cumulative precipitation index of available water in natural systems in Mindanao  have been crafted and make such estimates  possible.
Clavano earlier tracked Philippine  rising sea levels. They will be highest along the Pacific seaboard. That slices from Samar to eastern Mindanao, the Zamboangas, plus the provinces of Romblon and Marinduque in the Sibuyan Sea.

El Niño  will possibly have a lesser impact on the Agusan valley in eastern Mindanao because there is more available ground moisture, Clavano writes. But it will  have a stronger impact on Bukidnon where there is more cropland on a plateau with the rivers set in deep canyons.

Take a typical upland Bukidnon village like Bendum. Its annual average rainfall is 2,240 mm.  The impact of El Niño as calculated translated to a 30-percent  deficit of 364 mm by mid-April. That shortfall  will be more  today.

Forget  cloud seeding. Costing a thousand US dollars  per flying hour, it  forms  one-off type of activity, useful only  for the press release.  The agriculture department is therefore  distributing shallow tube wells, drought-tolerant crop varieties, and exploring water saving technologies. “These responses are however limited to lowland contexts. Up and upland situations are not considered.”

Crop alternatives have not been explained well. Slow growing  root crops such as sweet potato, cassava, and yam are crucial for food security in future and more intense El Niños.

El Niño is a weather changer, Walpole writes.  We’re  learning to adapt   as we understand a little more  of this  phenomenon that  impacts all continents through the atmosphere and jet stream.
Every 20 years or so,  an intense El Niño hits due to major sea temperature changes in the Pacific. The result is  drought that  sears much of  Southeast Asia down to Australia, then on to   parts of South America and Southeast Africa. The most severe droughts were 1982-1983 and 1997-1998.

El Niño is  associated with destruction of  sardine shoals off Peru (east Pacific)  at Christmas when traditional Misa de Gallos or  dawn masses are celebrated. Our knuckles tighten when  it emerges, second quarter of the year, 6,000 kilometers  away from Peru:  But it will take about three to four months before rainfall patterns are affected here. Add  a few more months before a drought becomes  perceptible as it spreads.

The Oceanic Niño Index (ONI) is a key warning tool.  If there is an ONI  surge  of more than 0.5 above the normal temperature, then El Niño is declared. This threshold was breached here last April, May, and June and El Niño was duly announced. In 1997,  the variance was 2.38 above the average.

The warmer water of Niño 3.4 region does not reach the Philippines.  But passing  over the warm sea, the air slowly increases in temperature and moves westward. The winds and wind power are weakened.  Typhoons are less likely to form.

A storm surge like Yolanda (Haiyan) can’t happen during the months of El Niño. That’s cold comfort  because  the rains have often turned disastrous. Today’s El Niño clones the 1997-1998 pattern.  The threat is much less. But there is a 75 percent  probability  that  a water shortfall may exceed   30 percent.

The rains  weakened  over the months, until storm “Mario”. The reduced rains will be most critical here next month. In other regions on earth, El Niño  dumps  heavy rainfall and La Niña would indicate drought. That seems the opposite of what happens here.

Why?  During an El Niño, westerly winds along the equator that drive the moisture-laden air towards the Philippines weaken. Much rain falls on over the open  seas.  The warm pool also has the energy to generate more evaporation than normal.

Rainfall supplies water to the environment  depending on the speed at which it travels through the hydrological system. Moisture  is essentially stored on land and becomes available at a later time.
This delay allows drought to be forecast in advance of water supply decisions.

Depending on nature of the water resource, the distribution system in place, and primary use of the water, the lead time could be a few months. Hence the critical priority for water storage and local dams.

By  New Year, we will know the final outcome of the 2014 El Niño. May it never “arrive” in the Upper Pulangi  area of Mindanao or   even  “Hacienda Binay” in Rosario Batangas.  The stronger the Oceanic Nino Index, the more reliable is the reading of subsequent effects.

Despite improved tracking confidence  drought forecasts still remain shaky.  A mild drought might even be a boon to farmers in the lowland  valleys   where they grouse that  they get too much rain now when compared to past records.

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