Projected Changes in Drought Severity and Spatial Patterns across Türkiye under RCP4.5 and RCP8.5 Scenarios

Year 2025, Volume: 19 Issue: 57, 35 - 47, 01.12.2025

Ali Kaan Yetik , Burak Nazmi Candoğan

https://doi.org/10.5281/zenodo.17568859

Abstract

This study evaluates the future impacts of climate change on drought severity across Türkiye using high-resolution climate projections from three Global Climate Models (GFDL-ESM2M, HadGEM2-ES, MPI-ESM-MR) under RCP4.5 and RCP8.5 scenarios. Drought conditions were assessed using the 12-month Reconnaissance Drought Index (RDI-12), which integrates both precipitation and evapotranspiration (ETo), for historical (1971–2000), near-future (2023–2052), and distant-future (2069–2098) periods. The Mann-Kendall test was used to detect trends, while Sen’s slope estimator and spatial visualization techniques were applied to assess the magnitude and spatial distribution of changes. Results indicate a significant increase in drought frequency and severity, particularly under the RCP4.5 and RCP8.5 scenarios. Multi-model averages indicate a projected increase of up to 21% in extreme drought frequency (RDI ≤ –2) in the near future under RCP4.5. Central Anatolia, Eastern Mediterranean, and parts of Eastern Anatolia were identified as regions highly vulnerable to intensified drought. Spatial analyses revealed considerable regional heterogeneity, showing varying drought trends depending on the climate model and emission scenario. Overall, the study emphasizes the critical need for region-specific drought mitigation strategies and robust adaptation policies to safeguard agricultural productivity and water resource sustainability under anticipated climate change scenarios.

Keywords

GCMs , GIS , RCP4.5 , RCP8.5 , spatial analysis , Türkiye

Thanks

This study contains partial findings of the PhD dissertation of Ali Kaan Yetik. The authors are gratefully acknowledged to the Turkish State Meteorological Service for sharing meteorological data used for this study.

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