Ecology, Environment and Conservation Paper

TREND DETECTION IN ANNUAL PRECIPITATION AMONG THE TOP RICE PROVINCES IN THE PHILIPPINES USING MANN KENDALL TEST

Natividad Dulce Madrazo, Vicente Salvador E. Montaño and Rodjard B. Paro

Abstract

Global warming and agriculture are inextricably linked to each other. Continued changes in the intensity of precipitation due to climate change will have an effect in agricultural production. The aim of this research was to detect the trend in annual precipitation among the top rice- producing provinces in the Philippines using Mann Kendall Test. The study used 12-month data accumulation on precipitation from 10 provinces from 1990 to 2012. Mann-Kendall Test was used to determine the presence of a monotonic increasing or decreasing trend while Sen’s method was used to estimate the slope of a linear trend. The results of the test revealed conformity. Sen’s slope showed that there is an increase in precipitation in 9 of 10 top rice provinces while Mann Kendall Test demonstrated that significant increasing trend was noticeable in 4 of the 10 provinces monitored. The findings can be used to aid legislators and other stakeholders to craft policies like irrigation and flood control in the context of climate change.