Assessing future drought scenarios in Rangpur, Bangladesh using CMIP6 climate projections and drought indices

Authors

• Mijanur Rahman, University of Chittagong
• Hossain Al Mahbub, University of Chittagong
• Mst Sanjida Alam, Clark University
• Janifer Alam, Dhaka International University
• Nusrut Sharmin, University of Chittagong
• Md Naim Molla, University of Chittagong

Document Type

Article

Abstract

Climate-induced drought has become a growing concern across South Asia as rising temperatures and monsoon variability intensify hydroclimatic stress. This study evaluates historical (1979–2014) and future (2015–2100) hydroclimatic conditions in Rangpur using observed data and CanESM5 projections for three CMIP6 scenarios (SSP1-1.9, SSP2-2.6, SSP5-8.5). Multi-scale Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) were applied to detect droughts, while Tmax and Tmin Z-scores quantified heat anomalies and compound drought–temperature events. Historical records show strong rainfall variability with no significant long-term trend, but significant warming particularly in Tmin indicating increasing evaporative demand. Future projections reveal moderate precipitation increases (+ 180 to + 680 mm/year) but substantially stronger warming (+ 1.1 to + 4.8 °C for Tmax; +2.1 to + 6.1 °C for Tmin). SPEI-based droughts occur more frequently than SPI droughts across all SSPs, reflecting the temperature-driven moisture deficits. Marked intensification of compound warm-night and hot-day drought events is found under SSP5-8.5, indicating a shift toward persistent, heat-amplified drought regimes. Findings suggest that future drought risk in Rangpur will be governed less by rainfall decline and more by concurrent warming and moisture stress, underscoring the need for adaptation strategies addressing compound heat–drought hazards in northern Bangladesh. © The Author(s) 2026.

Publication Title

Discover Geoscience

Publication Date

12-2026

Volume

4

Issue

1

ISSN

2948-1589

DOI

10.1007/s44288-026-00566-7

Keywords

climate model, CMIP6, drought, SPEI, SPI, SSP, Z-Score

Repository Citation

Rahman, Mijanur; Mahbub, Hossain Al; Alam, Mst Sanjida; Alam, Janifer; Sharmin, Nusrut; and Molla, Md Naim, "Assessing future drought scenarios in Rangpur, Bangladesh using CMIP6 climate projections and drought indices" (2026). Student Publications [Scholarly]. 115.
https://commons.clarku.edu/student_publications/115

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Copyright Conditions

Rahman, M., Mahbub, H. A., Alam, M. S., Alam, J., Sharmin, N., & Molla, M. N. (2026). Assessing future drought scenarios in Rangpur, Bangladesh using CMIP6 climate projections and drought indices. Discover Geoscience, 4(1), 199. https://doi-org/10.1007/s44288-026-00566-7