Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/hess-2017-253
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
15 Jun 2017
Review status
This discussion paper is a preprint. A revision of the manuscript is under review for the journal Hydrology and Earth System Sciences (HESS).
Global change in flood and drought intensities under climate change in the 21st century
Behzad Asadieh and Nir Y. Krakauer Civil Engineering Department and NOAA-CREST, The City College of New York, City University of New York, New York, USA
Abstract. Global warming is expected to intensify the Earth’s hydrological cycle and increase flood and drought risks. Changes in global high and low streamflow extremes over the 21st century under two warming scenarios are analyzed as indicators of hydrologic flood and drought intensity, using an ensemble of bias-corrected global climate model (GCM) fields fed into different global hydrological models (GHMs). Based on multi-model mean, approximately 37 % and 43 % of global land areas are exposed to increases in flood and drought intensities, respectively, by the end of the 21st century under RCP8.5 scenario. The average rates of increase in flood and drought intensities in those areas are projected to be 24.5 % and 51.5 %, respectively. Nearly 10 % of the global land areas are under the potential risk of simultaneous increase in both flood and drought intensities, with average rates of 10.1 % and 19.8 %, respectively; further, these regions tend to be highly populated parts of the globe, currently holding around 30 % of the world’s population (over 2.1 billion people). In a world more than 4 degrees warmer by the end of the 21st century compared to the pre-industrial era (RCP8.5 scenario), increases in flood and drought intensities are projected to be nearly twice as large as in a 2 degree warmer world (RCP2.6 scenario). Results also show that GHMs contribute to more uncertainties in streamflow changes than the GCMs. Under both forcing scenarios, there is high model agreement for significant increases in streamflow of the regions near and above the Arctic Circle, and consequent increases in the freshwater inflow to the Arctic Ocean, while subtropical arid areas experience reduction in streamflow.

Citation: Asadieh, B. and Krakauer, N. Y.: Global change in flood and drought intensities under climate change in the 21st century, Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-253, in review, 2017.
Behzad Asadieh and Nir Y. Krakauer
Behzad Asadieh and Nir Y. Krakauer
Behzad Asadieh and Nir Y. Krakauer

Viewed

Total article views: 810 (including HTML, PDF, and XML)

HTML PDF XML Total Supplement BibTeX EndNote
657 141 12 810 27 5 19

Views and downloads (calculated since 15 Jun 2017)

Cumulative views and downloads (calculated since 15 Jun 2017)

Viewed (geographical distribution)

Total article views: 810 (including HTML, PDF, and XML)

Thereof 801 with geography defined and 9 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 18 Oct 2017
Publications Copernicus
Download
Short summary
Multi-model analysis of global daily streamflow extremes for the 20th and 21st centuries under two warming scenarios is performed. About 37 % and 43 % of global land areas are exposed to increases in flood and drought intensities. Nearly 10 % of global land areas, holding around 30 % of world’s population, will face increases in both flood and drought risks. Significant increase in streamflow of the regions near and above the Arctic Circle, and decrease in subtropical arid areas, is projected.
Multi-model analysis of global daily streamflow extremes for the 20th and 21st centuries under...
Share