Spatiotemporal variability of future water sustainability using reliability resilience vulnerability framework

Drought projection is used to evaluate the risk of drought in future. Drought projection has been performed using the bias corrected General Circulation Models. However, it is necessary to have a reliable future projection, but the future is uncertain, and the bias correction method can affect the projection. This study evaluated the past and future drought projection over Pakistan and showed spatial distribution of frequency, duration, and severity over a region by using parametric and non-parametric transformation methods for bias correction. Drought was quantified using Standardized Precipitation Evapotranspiration Index (SPEI). Reliability-Resilience-Vulnerability (RRV) approach was used to analyze the drought for the historical (1981–2014), near future (2026–2059, NF) and far future (2066–2099, FF) periods. RRV value represents which region has the most sustainable water resources system. In NF of SSP2-4.5, the severity increases abruptly but duration of drought decreases while both severity and duration decrease in FF. Drought severity for SSP2-4.5 is higher than SSP5-8.5 in NF while the opposite was revealed in FF. The drought frequency didn’t undergo much of changes except for Balochistan which has a frequent drought in NF and FF for both SSP scenarios. NF of SSP2-4.5 showed reduction in RRV values implementing the increase in water availability while the opposite was revealed in FF. RRV values for SSP5-8.5 indicate that droughts become more severe in FF. The parametric transformation method showed more severe droughts for future than the non-parametric transformation. The finding of this study could help water resources managers and farmers to plan and adapt to changes in climate.