Trend Analysis of Drought Indicators in Terms of Rice Yield for Drought Identification in a Type III Climate Area in Central Philippines  
Author Jozil Donne D. Cerna


Co-Author(s) Maulyn Murielle S. Dominguez; Vinna Ysabelle U. Tupas; Aris C. Larroder


Abstract The most utilized drought indices are the Standard Precipitation Index (SPI) and the Standard Precipitation Evapotranspiration Index (SPEI), which are based on precipitation and temperature data. In the Philippines, only SPI is utilized by the Philippine Atmospheric Geophysical Astronomical Services Administration (PAGASA) and only as a tool for disaster risk management. This study aims to analyze the trend of SPI and SPEI for drought identification in terms of rice yield in a Type III Climate area. Climate parameters were run through the Mann-Kendall test to determine trend significance, and rice yield was correlated to the drought magnitudes of SPEI and SPI. It was found that neither of the drought indices had a specific monotonic trend on a 12-month timescale. Rice yield had a weak positive correlation with SPEI and a weak negative correlation with SPI, depicting the indices as weak agricultural indicators. There was also no constant upward or downward trend in each drought index, suggesting values varied over time. However, other studies have found that this correlation is much stronger on a shorter timescale.


Keywords Increasing temperature, rice yield, drought indices, potential evapotranspiration, precipitation
    Article #:  DSBFI23-60
Proceedings of 2nd ISSAT International Conference on Data Science in Business, Finance and Industry
January 8-10, 2023 - Da Nang, Vietnam