Trend analysis of climate and water use efficiency in palm oil area in Malaysia with remote sensing

The world population growth is projected to greater than 9 billion in 2050, boosting the demand for palm oil with approximately more than double of the current world production. Malaysia is the second largest palm oil producer in the world. However, it has been experiencing the labor shortage in the last decade. Also, land expansion for newly established palm oil plantation is severely restricted to avoid further deforestation. In addition, the impact of climate change is ambiguous. These situations will limit the growth of palm oil production in the country. Therefore, the increase of efficiency of palm oil production within the limited resource under climate change is crucial for meeting the future demand. To improve the efficiency, prioritizing the potential area which is suitable for palm oil growth and stable under climate change is one of strategies. While several studies report the suitable area for palm oil in Malaysia with the prediction under climate change, the resilience of palm oil to climate change is understudied.

This study aims to investigate the response of palm oil growth to the climatology obtained from satellite from 2010 to 2021. Satellite data used in this study are precipitation from GSMap, 2m surface temperature from ECMWF, gloss primary product (GPP) from MODIS, evaporation and transpiration from GLEAM, soil moisture and vegetation optical depth (VOD) from SMOS. In addition, water use efficiency (WUE) are calculated from GPP divided by transpiration. Water balance (Balance) is also obtained from precipitation subtracted by evaporation and transpiration. Satellite data is calculated for 8-day sum for precipitation and 8-day average for other variables, and the time series trends by Seasonal-Trend decomposition using LOESS (STL) are analyzed. The region of interest are patches of 0.25-degree grids in which Man-Kendall analysis showed the significant change of temperature and the grids with less significant change.

The result showed lower WUE in the grids where temperature has risen but precipitation is unchanged than in the grid where precipitation has increased. The grid without significant change of temperature and precipitation showed the lowest WUE through the period. The result implies that the increase of both precipitation and temperature may partially have the positive impact on palm oil production, while the effect may vary in places. Further investigation is needed.