Karakteristik kekeringan meteorologis dan pengaruh el niño–southern oscillation di Nusa Tenggara Timur

Abstract

Climate change has a significant impact on rainfall variability in tropical regions, including Indonesia. El Niño Southern Oscillation (ENSO) is one of the global climate phenomena that can trigger droughts in vulnerable regions such as Nusa Tenggara Timur (NTT). This study aims to analyze the characteristics of meteorological drought based on the Standardized Precipitation Index (SPI) on a 3-, 6-, and 12-month time scale, as well as to examine its relationship with El Niño dynamics using the Oceanic Niño Index (ONI) during the period 2010–2023. The results indicate that drought in NTT represents a recurrent annual phenomenon, with SPI-3 exhibiting the most extreme fluctuations. Spatial analysis indicates that Timor and Flores islands are predominantly characterized by prolonged drought events lasting 5–22 months, with severe intensity (reaching –49.00) and substantial monthly deficits (up to –2.18). Flores Island is characterized by prolonged cumulative drought conditions, whereas Timor Island exhibits consistently high monthly deficit intensities. Flash drought events were additionally observed across several localized regions. Correlation analysis between SPI and ONI demonstrates that the intense El Niño event (2014/2016) corresponded to substantial rainfall reductions, while the extreme drought conditions observed in 2019 were attributed to extreme positive IOD phenomena and monsoon circulation patterns.