Recent Advancement in Drought Index Using Remote Sensing Techniques: A Review

Dahiru M. Z.^1,2,3, Mazlan Hashim^{1, 2}, and Noor Dyana Hassan^1,2

Abstract: Drought monitoring is a key element of current drought preparedness approaches, providing critical information on recent conditions that can be used to trigger mitigation actions to lessen the impact of this natural threat. Drought can be both complex and challenging to monitor since it lacks a single universal definition, which makes findings intricate. Three effective and significantly grounded explanations were developed to differentiate and categorise drought types; namely, meteorological, agricultural, and hydrologic drought. Quite a lot of satellite-based drought indices have so far been suggested for regional and national levels. Meteorological and satellite-based indices are used to find diverse drought phenomena, including meteorological, agricultural and hydrological drought. The current remote sensing advancements have both confirmed useful for drought monitoring and prediction where some indicators provide a limited view of drought conditions, concentrating on vegetation health and agricultural drought. Several satellite-based remote sensing instruments have been advanced for drought monitoring and early warning. The numerous meteorological variables (indicators) such as precipitation, temperature, humidity and evapotranspiration are required to calculate drought severity level. The long-term historical records of satellite imagery and climatic data are essential to calculate drought severity levels and to determine drought risk-prone ranges. Recently quite a lot of satellite imagery has proven useful in agricultural drought assessment. Thus, the significance of new developed remote sensing-derived based drought indices will come to reality if researchers and experts for drought monitoring can come out with a new approach to integrating indices that will address both long-term and short-term drought effects concerning in-situ and satellite data to support the actualization of the SDG targets 2.4 by 2030 and 13.1, 13.2.

Key words:remote sensing, drought index, meteorological, agricultural, hydrological, socioeconomic droughts