Abstract. The increasing rate of occurrence of extreme events (droughts and floods)
and their rapid transition magnify the associated socio-economic impacts
with respect to those caused by the individual event. Understanding of
spatio-temporal evolution of wet–dry events collectively, their
characteristics, and the transition (wet to dry and dry to wet) is therefore
significant to identify and locate most vulnerable hotspots, providing the
basis for the adaptation and mitigation measures. The Upper Jhelum Basin
(UJB) in South Asia was selected as a case study, where the relevance of
wet–dry events and their transition has not been assessed yet, despite
clear evidence of climate change in the region. The standardized
precipitation evapotranspiration index (SPEI) at the monthly timescale was
applied to detect and characterize wet and dry events for the period
1981–2014. The results of temporal variations in SPEI showed a strong change
in basin climatic features associated with El Niño–Southern Oscillation
(ENSO) at the end of 1997, with the prevalence of wet and dry events before
and after 1997 respectively. The results of spatial analysis show a higher
susceptibility of the monsoon-dominated region towards wet events, with more
intense events occurring in the eastern part, whereas a higher severity and
duration are featured in the southwestern part of the basin. In contrast, the
westerlies-dominated region was found to be the hotspot of dry events with
higher duration, severity, and intensity. Moreover, the surrounding region
of the Himalaya divide line and the monsoon-dominated part of the basin were
found to be the hotspots of rapid wet–dry transition events.