A comparative study of past and projected future dynamics of drought hazards across the districts of the Northern Cape Province, South Africa: analysis of CRU TS4 data and CORDEX-Africa RCM simulations

Drought is among the most pressing natural disasters of the 21st century. The need for insights to support local decision-making in planning and mitigation is critical. The Northern Cape Province of South Africa is highly drought-prone, yet its historical and projected drought patterns are not well understood. Therefore, this study assessed past (1962-2022), near-future (2023-2050), and far-future (2051-2100) drought dynamics across its five district municipalities-Frances Baard, John Taolo Gaetsewe, Namakwa, Pixley Ka Seme, and ZF Mgcawu-using CRU data and CORDEX-Africa RCM simulations based on CMIP6. Drought characteristics were analyzed using the Standardized Precipitation-Evapotranspiration Index (SPEI) at 6-, 12-, and 24-month timescales. Results revealed significant spatial and temporal variability. Frances Baard and John Taolo Gaetsewe experienced the most frequent short-term droughts, with far-future projections indicating a significant intensification of drought events (up to 8.2 events/decade for the 6-month SPEI). Namakwa and Pixley Ka Seme recorded the longest multi-year droughts historically (up to 78 months for the 24-month SPEI), with far-future projections showing continued severity for long-term droughts. Mann-Kendall trend analysis indicated significant upward trends in drought frequency and duration in Frances Baard and John Taolo Gaetsewe, while Namakwa showed mixed trends-a near-future decline followed by far-future intensification.