Abstract
In the Philippines, as in other Southeast Asian countries, adequate supply of water for irrigation is significant for ensuring consistent high yields. This phenomenon becomes even more significant with the occurrences of El Nino-related droughts in the region. Using multi-temporal remotely-sensed images (MOS-1 and ADEOS), the study looks into the effect of El Nino-related drought on agricultural productivity in Central Luzon.
Introduction
Central Luzon is the rice granary of the Philippines with an economy that is propelled mainly by agriculture (1998 Philippine Yearbook). With a total rice land area of 530, 463 hectrares, the region produces about one-third of the harvest of the country (Salita, 1997, Huke and Kuke, 1997). In 1990, the total rice production of the area was 1,875,909 metric while in 1994, rice production was reduced to 1,197,855 (Provincial Rice Statistics, 1995).
In Central Luzon, as in other parts of the country, the biggest problem faced by farmers is the lack of adequate control of water, both in the amount available and in distribution throughout the growing season. It is the most serious physical constraint to consistently high yield (Huke and Huke, 1997). One reason for this problem is the lack of systematic irrigation network in the area. These phenomena led to the development of several water control-based schemes. Based on these schemes, agricultural lands in the area were classified as (a) irrigated wet and dry season and (b) non-irrigated wet and dry seasons.
According to Huke and Huke (19997), an irrigated wet season refers to areas to which water may be added using a source other than local rainfall or local runoff while an irrigated dry season refers to areas subject to the addition (or removal) of water during the local dry period. On the other hand, non-irrigated wet and dry seasons will be referred in the study as areas that are rainfed or watered by deep well either during the wet or dry seasons.
The effects on agricultural yields of the lack of adequate water supply for irrigation are aggravated whenever El Nino is experienced in the area. In 1997, Central Luzon was one of the hardest hit regions of El Nino-related drought events in the country. Lack of rain since the supposed onset of the rainy season in the month of May delayed the planting
season. In other cases particularly in the rain fed areas farmers have not planted rice. This situation was also experienced during the 1990 El Nino occurrence (Morales, 1997)
Objectives
The study utilized multitempral MOS-1 and ADEOS images to map the extent of irrigated lands affected by the El Nino phenomenon.
Specifically, the study aims to: (a) present the conditions in the study areas when El Nono was severely felt and when it was not; (b) measure the extent of El Nino damages and the relative decline in productivity of the agricultural land in Central Luzon: and (c) provide valuable information about El Nino to policy makers which can be used in formulating appropriate plants and programs to avoid or mitigate the impact of this hazard.
Study Area
San Fernando is the capital of the province of Pampanga. It has a total farm land area of 635 hectares. It is fast developing area that for a long time has served as the administrative capital of Central Luzon. It is approximately 60 kilometers away from Metro Manila.
