Recent Changes in Drought Events over South Asia and Their Possible Linkages with Climatic and Dynamic Factors

South Asia is home to one of the fastest-growing populations in Asia, and human activities are leaving indelible marks on land surface. Yet likelihood successive observed droughts (SA) its four subregions (R-1: semi-arid, R-2: arid, R-3: subtropical wet, R-4: tropical wet dry) remains poorly understood. Using state-of-the-art self-calibrated Palmer Drought Severity Index (scPDSI), we examined impact different natural ocean variability modes evolution, severity, magnitude across that have distinct precipitation seasonality cover key breadbaskets highly vulnerable populations. The study revealed dryness had significantly increased R-1, R-2, R-4 during 1981–2020. Temporal analysis an increase drought intensity for R-1 since 2000s, while a mixed behavior was R-2 R-3. Moreover, most sub-regions witnessed substantial upsurge annual precipitation, but significant decrease vapor pressure deficit (VPD) decline VPD partially contributed rise Normalized Difference Vegetation (NDVI) dryness. In contrast, strong positive correlation found between index NDVI R-4, whereas temperature exhibited negative over these regions. No obvious link detected with El-Niño Southern Oscillation (ENSO) events, or Indian Ocean Dipole (IOD) as explored certain regions SA. findings showed possibility changes insignificant relationship ENSO, IOD, onset. Thus, results highlight need considering interactions within longer climate system describing risks rather than aiming at drivers from individual perspective.