Assessment of Meteorological Drought in Merauke Regency Using the Standardized Precipitation Index (SPI)

Abstract

This study investigates drought variability and prediction in Kurik District, Merauke Regency, South Papua, using the Standardized Precipitation Index (SPI). A 20-year dataset of monthly rainfall (2004–2023) and the Southern Oscillation Index (SOI) were analyzed. Data quality assessments, including consistency (RAPS), trend (Spearman rank), stationarity (F-test and t-test), and persistence (autocorrelation), confirmed that the dataset was statistically valid for time-series analysis. The SPI-1 analysis identified that the most severe drought occurred in March 2021, with an index value of –3.145 categorized as extreme drought. Correlation analysis revealed a weak relationship between SPI and SOI (r = 0.189), indicating that ENSO events exerted minimal influence on local drought dynamics. Rainfalls prediction for the period 2024–2033 was conducted using the Thomas–Fiering stochastic model. The results indicated that the most extreme drought event is projected to occur in April 2029 (SPI = –3.017), while the longest drought duration is expected in 2025, lasting for seven consecutive months. These findings provide scientific evidence for supporting agricultural adaptation, water resource planning, and climate risk mitigation in South Papua. The study highlights the importance of integrating localized drought monitoring with predictive modeling to strengthen regional resilience against climate variability.