Future meteorological droughts in the Southeastern US

Authors

• Kunal Bhardwaj, Clemson UniversityFollow
• C. Prakash Khedun, Clemson UniversityFollow
• Abdul A. Khan, Clemson UniversityFollow

Article Type

Full Research Article – Regular Issue

Volume

10

Issue

1

Abstract

The Southeastern U.S., despite its humid climate, experiences recurrent meteorological droughts which impact agricultural, water resources, ecological systems, and the economy and society. Knowledge of future drought conditions can guide adaptation efforts. Here, we evaluate historical and projected droughts using the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI) computed from an ensemble of eight bias-corrected Global Climate Models (GCMs) from the Climate Model Intercomparison Phase-6 (CMIP6). The historical performance (1950–2014) of the GCM’s mean was benchmarked against gridded observations from the Climate Research Unit (CRU). Future changes were assessed under 1.5°C, 2.0°C, and 3.0°C global warming levels.We found that bias-corrected GCMs underestimate historical drought duration, frequency, and severity, across the region. Model projections reveal a divergence between SPI and SPEI responses: droughts, identified using SPI, are projected to decline whereas those identified using SPEI are expected to increase significantly, attributed to an expected rise in evaporative demand. Thus, despite projected increases in precipitation across the Southeast, these gains may be offset by an increase in temperatures and evapotranspiration, ultimately intensifying drought risk.

Takeaway(s)

Droughts, analyzed from CMIP6 model runs, is likely to get worse in the Southeastern US.

Both precipitation and evapotranspiration will increase but the net balance will result in harsher droughts in the future.

Recommended Citation

Bhardwaj, Kunal; Khedun, C. Prakash; and Khan, Abdul A. (2025) "Future meteorological droughts in the Southeastern US," Journal of South Carolina Water Resources: Vol. 10 : Iss. 1 , Article 5.
Available at: https://open.clemson.edu/jscwr/vol10/iss1/5