A STUDY IN IDENTIFICATION OF FLASH DROUGHT PHENOMENA IN INDONESIA

• Main Author: Wulandari, Putri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/85180
• Institution: Institut Teknologi Bandung

The phenomenon of rapidly developing droughts, known as flash droughts, often goes undetected by conventional drought monitoring and early warning systems. Various studies developed identification methods to reduce the risk and capture the unique characteristics distinguishing flash droughts from conventional droughts. However, the lack of a universally accepted quantitative definition has led to uncertainty in identifying flash droughts in previous studies. The frequency, distribution, and intensity of flash droughts tend to vary depending on the methods, criteria, and indicators applied in identification. Global studies using the soil moisture percentile approach have identified the Indonesia Maritime Continent (IMC) as a hotspot region. Nevertheless, this finding remains unconfirmed due to limitations in observational data and the application of criteria based on studies conducted in mid-latitude and subtropical regions. This study identifies flash droughts in the IMC by modifying the soil moisture percentile approach, with adjustment in the criteria of intensification rate for tropical regions based on sensitivity tests. The spatio-temporal distribution of flash drought intensity considers both the intensification rate and drought severity as the key characteristics of flash drought. The analysis indicates that variations in the intensification rate criteria significantly influence the frequency of flash drought events, with the IMC being detected as a global hotspot due to the application of overly sensitive criteria. Flash droughts in Indonesia generally develop within 1-2 pentads, with seasonal variations in hotspot areas. The intensity of these events tends to be high throughout the year in Central Papua and Southern Papua Provinces, reflecting the rapid intensification period as the climatological characteristics of the region.