THE INFLUENCE OF INDIAN OCEAN DIPOLE (IOD) ON HYBRID COCONUT PRODUCTIVITY IN CENTRAL JAWA PROVINCE

• Main Author: Brahmantyo Wardana, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/86206
• Institution: Institut Teknologi Bandung

The Indian Ocean Dipole (IOD) is an ocean-atmosphere phenomenon that affects rainfall intensity in Indonesia, including Central Java Province, one of the largest producers of hybrid coconuts in Indonesia. Rainfall is a key factor determining the productivity of hybrid coconuts, so fluctuations in rainfall intensity will impact hybrid coconut productivity. Research is needed to understand the influence of the Indian Ocean Dipole (IOD) on hybrid coconut productivity in Central Java Province. This study utilizes monthly rainfall and Dipole Mode Index (DMI) data from 2011- 2022, as well as annual data on hybrid coconut productivity in Central Java Province. Rainfall data are processed and used to examine the response of hybrid coconut productivity to the IOD phenomenon in the study area. Wavelet Transform and Butterworth Bandpass Filter are employed to process the DMI and rainfall data. The rainfall pattern in Central Java Province is monsoonal, as evidenced by the climatological rainfall pattern produced from the six studied regencies (Semarang Regency, Demak Regency, Kendal Regency, Batang Regency, Banjarnegara Regency, and Klaten Regency). IOD, as an interannual phenomenon, has a small influence across the study area, as shown by the R-squared values (ranging from 0.03 to 0.24). The impact of IOD-induced rainfall on hybrid coconut productivity shows varying relationships, with moderate R-squared values (0.56) in Klaten Regency and weak R-squared values (0.03) in Demak Regency. Similarly, the relationship between IOD and hybrid coconut productivity shows moderate Rsquared values (0.47) in Klaten Regency and no relationship (0) in Demak Regency.