Spatial and temporal effects of El Niño on Philippine rainfall and cyclones

Issue Date

12-2006

Abstract

Seven El Niño events (1997-98, 1994-95, 1990-93, 1986-88, 1982-83, 1977-78 and 1972-73) were studied to determine their effects on rainfall and tropical cyclones in the Philippines. Percent deviation from the mean monthly rainfall and the number and tracks of tropical cyclones were mapped with the aid of an ArcView® GIS software to show the spatial and temporal effects of each event. The results showed that the effect of each El Niño event on monthly rainfall and tropical cyclones is unique and depends on its intensity, location, area coverage, duration and time of occurrence. Nevertheless, some general patterns can be observed. The effect of El Niño on rainfall is initially felt 3-5 mo after the development of a warm episode in the tropical Pacific. Recovery from El Niño starts in Mindanao (then moves in a northeasterly direction) when the sea surface temperature (SST) in the tropical Pacific returns to normal. The monthly rainfall received in most parts of the country was reduced by more than 50% during the peak of a strong event. Strong El Niño events suppressed tropical cyclone activity while weak-to-moderate events did not, but shifted northeast the tracks of tropical cyclones. Information generated in this study will help decision makers and planners formulate appropriate intervention measures to cope with the adverse effect of El Niño on agriculture and assess the vulnerability to El Niño-induced drought of important agricultural commodities in the different agro-ecological zones of the country.

Source or Periodical Title

Philippine Agricultural Scientist

ISSN

317454

Volume

89

Issue

4

Page

296-308

Document Type

Article

Language

English

Subject

ArcView® GIS, El Niño, IDW, Interpolation, Rainfall, Tropical cyclones

Digital Copy

none

This document is currently not available here.

Share

COinS