Future Intensification of Drought and Heatwaves in Quetta Valley Based on SSP Pathways

Future Intensification of Drought & Heatwaves in Quetta Valley Based on SSP

Abstract

Quetta Valley is increasingly vulnerable to climate-induced droughts and heatwaves, as indicated by historical observations and future climate projections. The Standardized Precipitation Index (SPI-12) shows values ranging from approximately 0 to –2.5, reflecting frequent moderately to severely dry conditions over the study period. Trend analysis using the Mann-Kendall test indicates a weak negative slope of –0.00013 for observed data (p = 0.736), suggesting a slight tendency toward drier conditions; however, the trend is not statistically significant. Similarly, future projections under SSP245 and SSP585 scenarios show small negative slopes (–0.000075) with p-values of 0.483 and 0.495, respectively, indicating no statistically significant drying trend. These results suggest that drought conditions are likely to persist with minor variations rather than intensify significantly. Heatwave analysis reveals no events in the observed dataset based on the defined thresholds, whereas future projections indicate a substantial increase in both moderate (>40 °C) and severe (>45 °C) heatwaves. The frequency of 5-day heatwave events is consistently higher than 7- and 10-day events, highlighting the increasing persistence of short-duration heat stress. These findings suggest that while drought conditions may remain relatively stable, heatwave intensity and frequency are expected to increase significantly under future climate scenarios, particularly under SSP585. The combined occurrence of droughts and heatwaves poses serious risks to water resources, agriculture, and public health in Quetta Valley. The study highlights the urgent need for climate-resilient water management strategies and adaptive planning to mitigate the impacts of future climate extremes.