Karakteristik Kekeringan Meteorologis serta Keterkaitannya Dengan ENSO dan IOD Menggunakan Standardized Precipitation Index Di Kabupaten Bantul

Dewi Muthmainah, Prof. Bayu Dwi Apri Nugroho, S.T.P., M.Agr, Ph.D, IPU., ASEAN Eng. ; Chandra Setyawan, S.T.P., Ph.D, IPM, ASEAN Eng., APEC Eng.

2026 | Skripsi | TEKNIK PERTANIAN

Kekeringan meteorologis merupakan salah satu bencana hidrometeorologi yang dipengaruhi oleh variabilitas curah hujan dan fenomena iklim global. Kabupaten Bantul memiliki kerentanan terhadap kondisi tersebut karena aktivitas pertanian yang bergantung pada ketersediaan air hujan. Penelitian ini bertujuan menganalisis karakteristik kekeringan meteorologis di Kabupaten Bantul menggunakan Standardized Precipitation Index (SPI), serta mengevaluasi pengaruh dan keterkaitan El Niño–Southern Oscillation (ENSO) dan Indian Ocean Dipole (IOD) terhadap kondisi kekeringan. Penelitian menggunakan data curah hujan satelit CHIRPS periode 2004–2024 yang telah melalui uji homogenitas dan validasi terhadap data observasi. Hasil validasi menunjukkan nilai R sebesar 0,98, NSE sebesar 0,95, RMSE sebesar 40,43 mm, dan Bias sebesar 20,68 mm, sehingga data CHIRPS layak digunakan dalam analisis kekeringan. Analisis kekeringan dilakukan menggunakan SPI pada skala waktu 1, 3, 6, dan 12 bulan, sedangkan hubungan antara SPI dengan ENSO dan IOD dianalisis menggunakan korelasi Pearson dan lead–lag correlation.

Hasil penelitian menunjukkan bahwa SPI-1 dan SPI-3 lebih sensitif terhadap fluktuasi curah hujan jangka pendek, sedangkan SPI-6 dan SPI-12 lebih mampu menggambarkan kekeringan yang bersifat persisten. Periode kekeringan utama teridentifikasi pada tahun 2012–2016 dan kembali terjadi pada 2022–2023. Analisis korelasi Pearson menunjukkan bahwa hubungan SPI dengan ENSO memiliki koefisien korelasi ?0,06 hingga ?0,12, sedangkan hubungan SPI dengan IOD berkisar antara 0,04–0,17. Analisis lead–lag correlation menunjukkan adanya jeda respons sekitar 2–6 bulan antara variabilitas iklim global dan kondisi kekeringan meteorologis di Kabupaten Bantul.

Meteorological drought is one of the hydrometeorological disasters influenced by rainfall variability and global climate phenomena. Bantul Regency is particularly vulnerable to meteorological drought due to its agricultural activities, which largely depend on rainfall availability. This study aims to analyze the characteristics of meteorological drought in Bantul Regency using the Standardized Precipitation Index (SPI) and to evaluate the influence and relationship of the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) on drought conditions. The study utilized CHIRPS satellite rainfall data for the perIOD 2004–2024, which were subjected to homogeneity testing and validation against observed rainfall data. The validation results showed a correlation coefficient (R) of 0.98, a Nash–Sutcliffe Efficiency (NSE) of 0.95, an RMSE of 40.43 mm, and a Bias of 20.68 mm, indicating that the CHIRPS dataset is suitable for meteorological drought analysis. Drought conditions were analyzed using SPI at 1-, 3-, 6-, and 12-month time scales, while the relationships between SPI, ENSO, and IOD were examined using Pearson correlation and lead–lag correlation analyses.

The results indicate that SPI-1 and SPI-3 are more sensitive to short-term rainfall fluctuations, whereas SPI-6 and SPI-12 better represent persistent drought conditions. Major drought events were identified during 2012–2016 and recurred in 2022–2023. Pearson correlation analysis revealed that the relationship between SPI and ENSO was negative but very weak, with correlation coefficients ranging from ?0.06 to ?0.12, while the relationship between SPI and IOD was positive but also very weak, ranging from 0.04 to 0.17. Furthermore, the lead–lag correlation analysis indicated a response lag of approximately 2–6 months between global climate variability and meteorological drought conditions in Bantul Regency.

Kata Kunci : kekeringan meteorologis, SPI, ENSO, IOD, Kabupaten Bantul.