Mapping agricultural drought hotspots in Pakistan: a remote sensing-based climate–vegetation nexus

Agricultural drought is a significant threat to Pakistan’s food security, where climatic variability interacts with diverse topographic and hydro-climatic conditions. Using multisensor remote-sensing indices (TCI, VCI, VHI, NDVI, LST, and rainfall), this study analyzes drought dynamics from 2001 to 2023. Results reveal that drought occurrence is spatially heterogeneous and exhibits a seasonal structure. Northern high-altitude provinces (Azad Kashmir and Gilgit–Baltistan) remain relatively resilient, with more than 80% of their area free from drought and less than 5% exposed to extreme drought. In contrast, Sindh, Balochistan, and Punjab exhibit extensive vulnerability, with up to 99% of Punjab and approximately 92–94% of Sindh and Balochistan experiencing mild to severe droughts, while extreme drought affected 78–92% of their respective areas at least once. Climatic controls diverge by region. In the highlands, vegetation is temperature-limited, with strong positive NDVI–LST correlations (annual medians ~ 0.7–0.8) persisting across multiple 16-day lags. In arid lowlands, vegetation is water-limited, exhibiting negative NDVI–LST correlations (~–0.4 to − 0.6) but positive rainfall–NDVI relationships (~ 0.4–0.7) during the monsoon. Lag analysis indicates rapid greening within 16 days in humid regions, while heat-stressed plains recover only after 64–96 days. Trend analysis reveals positive decadal gains in vegetation indices, with the VCI and VHI increasing by 0.05–0.10 per decade and the NDVI by ~ 0.05 per decade in Punjab. In contrast, LST trends reveal spring cooling (~–1.5 to − 2.0 °C per decade) but localised summer warming in Balochistan (+ 1.0 °C per decade). Rainfall trends indicate intensified monsoon precipitation, particularly in Punjab and Azad Kashmir (by 70–150 mm per decade). Overall, mild drought is ubiquitous, moderate drought is common, and severe-to-extreme drought is regionally concentrated in the south and west. These findings underscore the urgency of region- and season-specific adaptation strategies, including early warning systems, climate-resilient cropping practices, and the use of monsoon-driven greening to mitigate drought impacts.