This study assessed future drought conditions in Harris County, Texas, using five Coupled Model Intercomparison Project Phase 6 (CMIP6) General Circulation Models (GCMs) under SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios for the period 2026–2085. The analysis employed the Standardized Precipitation Evapotranspiration Index (SPEI-6 and SPEI-12) to characterize drought, providing comprehensive insights into future drought risk. The results indicate a substantial increase in drought frequency, intensity, and severity in Harris County, particularly during the far-future period (2056–2085). The study identified an oscillating drought pattern: high frequency (1980–2002), temporary reduction (2003–2024), and projected intensification (2056–2085). Under medium and high emission scenarios, both SPEI-6 and SPEI-12 exhibit significant (p < 0.05) negative trends across the ensemble mean and most individual GCMs for the future period, in contrast to the historical period where both SPEI-6 and SPEI-12 demonstrate slight positive trends. Severity duration frequency curve analysis reveals that future droughts under SPEI-12 will be significantly more severe across all return periods (2–50 years). Although Harris County is experiencing relatively lower drought risk at present, the identified oscillating pattern and projected doubling of drought frequency under SSP5-8.5 represent a critical threshold for regional water security, requiring heightened attention from policymakers for proactive planning and adaptation strategies.
Abeysingha et al. (Wed,) studied this question.