Dynamics of the Standardized Precipitation Evapotranspiration Index (SPEI) of an oil palm plantation area in Jambi province, Indonesia

Abstract

Oil palm is susceptible to drought. Research to increase oil palm production continues to be developed, including the influence of drought to oil palm production. One of the methods used to analyze drought is using the Standardized Precipitation Evapotranspiration Index (SPEI). The purpose of this study is to analyze the dynamics of SPEI at diurnal, ten days periods, and monthly time scales, and their correlation with meteorological factors at an oil palm plantation in Jambi province, Indonesia for the year 2015. Using diurnal values, the SPEI does not indicate any drought as there are no values lower than -1. Using ten days periods, the SPEI shows a dry period starting from mid May to mid October. Using monthly values, the SPEI shows drought conditions with the driest month in October with SPEI reaching -2. Solar radiation and evapotranspiration are significantly correlated with the dynamics of diurnal index SPEI while precipitation affects significantly the dynamics of the SPEI at ten day and monthly periods.