Future changes in meteorological drought characteristics over Bangladesh projected by the CMIP5 multi-model ensemble
- PDF / 3,447,375 Bytes
- 19 Pages / 439.37 x 666.142 pts Page_size
- 93 Downloads / 199 Views
Future changes in meteorological drought characteristics over Bangladesh projected by the CMIP5 multi-model ensemble Jamal Uddin Khan, et al. [full author details at the end of the article] Received: 18 December 2018 / Accepted: 12 August 2020/ # Springer Nature B.V. 2020
Abstract
Drought is an inconspicuous natural disaster. In a warmer world, the severity and coverage of drought are expected to change, and it is essential to study these changes at smaller scale. This study detected changes in drought frequency, severity, and intensity in Bangladesh from a bias-corrected CMIP-5 multi-model projection of 11 members under a business-as-usual RCP8.5 scenario. We have used two well-known meteorological drought indices, Standardized Precipitation Index (SPI) and Standardized Precipitation and Evaporation Index (SPEI). SPI is solely based on precipitation, while SPEI considers climatic water balance and incorporates the effect of temperature. Two different methods of estimation of potential evapotranspiration (PET), namely Thornthwaite and Hargreaves methods, are explored. SPEI-based drought identification is found to have high sensitivity among these PET estimation methods. In Bangladesh, SPI-based analysis suggests virtually no change in the long-term drought (12-monthly) condition and a minor change in short-term (6-monthly or less) droughts. SPEI evaluated with Hargreaves method projects a similar scenario for long-term droughts but an increase in both drought frequency and severity in short timescales. At seasonal scale, winter and pre-monsoon are projected to be potentially more affected by water stress in the future. A spatially coherent shift in wet-dry regime is also found over the northern part of Bangladesh under the warming world. Keywords Climatic change . Drought . RCM . RCP . SPI . SPEI . Multi-model ensemble
Highlights • Multi-model ensemble projections of meteorological drought over Bangladesh • Hargreaves method underestimates droughts compared to the Thornthwaite method due to the low climate sensitivity in the DTR • Short spell drought (< 6 months) is also projected to become more severe in the future • In the pre-monsoon season, a spatially coherent dry-wet regime shift is projected between near and far future • Drought severity will continue to increase in the south-west region throughout the century • The north-west region will become wetter while the south-central region will become drier by the end of the century Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10584-02002832-0) contains supplementary material, which is available to authorized users.
Climatic Change
1 Introduction Drought is one of the costliest of all the natural disasters, and the effectiveness of managing drought is a major concern (Wilhite et al. 2014). It is a rare kind of disaster that sometimes passes by without even noticing it (Shaw and Nguyen 2011). Unlike all other destructive events like floods, cyclones, earthquake, or thunderstorm, the damage due to drought is mos
Data Loading...
