Spatiotemporal Characteristics of Meteorological Drought as a Basis for Strengthening Food Security in Banten Province

Abstract

Meteorological drought in monsoon-dominated regions can develop across different timescales and levels of severity; consequently, monitoring based on a single precipitation-accumulation period may fail to capture the full characteristics of drought events. This study analyzes the temporal variability, frequency, duration, inter-station heterogeneity, and descriptive association of drought with the El Niño–Southern Oscillation (ENSO) in Banten Province during 1991–2024. Daily precipitation records from observation stations across Banten were aggregated into monthly totals and used to calculate the Standardized Precipitation Index (SPI) at 1-, 3-, 6-, and 12-month timescales using the Gamma distribution. The analysis was conducted for four regional groups—Greater Tangerang, Greater Serang, Pandeglang, and Lebak—using regional ensemble means and station-level statistics. The results show that SPI-1 exhibits the most rapid dry–wet fluctuations, whereas SPI-3, SPI-6, and SPI-12 identify increasingly persistent events. The highest proportion of total dry months at SPI-1 occurred in Lebak (9.80%); at SPI-3, in Greater Tangerang and Lebak (11.58% each); and at SPI-6 and SPI-12, in Pandeglang (11.91% and 11.59%, respectively). Maximum drought duration increased with SPI timescale and reached 12 months at SPI-12 in Greater Tangerang, Pandeglang, and Lebak. Station-level analysis yielded median percentages of dry months ranging from 13.36% to 16.62%, indicating that regional averages may mask localized drought events. Moderate-to-strong El Niño phases were generally associated with declining SPI values, whereas La Niña more often coincided with recovery toward normal or wet conditions, although responses varied among regions and events. These findings underscore the need for multiscale and location-specific drought monitoring. SPI-3 can support seasonal preparedness and agricultural water management, whereas SPI-12 is more relevant for assessing persistent precipitation deficits and longer-term water-resource planning.