Sediment delivery to sustain the Ganges-Brahmaputra delta under climate change and anthropogenic impacts

Jessica L Raff; Steven L Goodbred Jr; Jennifer L Pickering; Ryan S Sincavage; John C Ayers; Md Saddam Hossain; Carol A Wilson; Chris Paola; Michael S Steckler; Dhiman R Mondal; Jean-Louis Grimaud; Celine Jo Grall; Kimberly G Rogers; Kazi Matin Ahmed; Syed Humayun Akhter; Brandee N Carlson; Elizabeth L Chamberlain; Meagan Dejter; Jonathan M Gilligan; Richard P Hale; Mahfuzur R Khan; Md Golam Muktadir; Md Munsur Rahman; Lauren A Williams

doi:10.1038/s41467-023-38057-9

Sediment delivery to sustain the Ganges-Brahmaputra delta under climate change and anthropogenic impacts

Nat Commun. 2023 Apr 27;14(1):2429. doi: 10.1038/s41467-023-38057-9.

Authors

Jessica L Raff¹, Steven L Goodbred Jr², Jennifer L Pickering³, Ryan S Sincavage⁴, John C Ayers⁵, Md Saddam Hossain³, Carol A Wilson⁶, Chris Paola⁷, Michael S Steckler⁸, Dhiman R Mondal⁹, Jean-Louis Grimaud¹⁰, Celine Jo Grall^{8

11}, Kimberly G Rogers¹², Kazi Matin Ahmed¹³, Syed Humayun Akhter¹⁴, Brandee N Carlson¹⁵, Elizabeth L Chamberlain¹⁶, Meagan Dejter⁵, Jonathan M Gilligan⁵, Richard P Hale¹⁷, Mahfuzur R Khan¹³, Md Golam Muktadir¹⁸, Md Munsur Rahman¹⁹, Lauren A Williams⁵

Affiliations

¹ Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA. jessica.l.raff@vanderbilt.edu.
² Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA. steven.goodbred@vanderbilt.edu.
³ Center for Applied Earth Science and Engineering Research, The University of Memphis, Memphis, TN, USA.
⁴ Department of Geology, Radford University, Radford, VA, USA.
⁵ Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA.
⁶ Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA, USA.
⁷ Department of Earth and Environmental Sciences, St Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN, USA.
⁸ Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.
⁹ Haystack Observatory, Massachusetts Institute of Technology, Westford, MA, USA.
¹⁰ Centre de Géosciences, PSL University/ MINES Paris, Fontainebleau, France.
¹¹ CNRS - Littoral Environnement et Sociétés, La Rochelle University, La Rochelle, France.
¹² Institute for Arctic and Alpine Research, University of Colorado, Boulder, CO, USA.
¹³ Department of Geology, University of Dhaka, Dhaka, Bangladesh.
¹⁴ Bangladesh Open University, Board Bazar, Gazipur, Bangladesh.
¹⁵ Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX, USA.
¹⁶ Soil Geography and Landscape Group, Wageningen University, Wageningen, Netherlands.
¹⁷ Department of Ocean & Earth Sciences, Old Dominion University, Norfolk, VA, USA.
¹⁸ Department of Environmental Science, Bangladesh University of Professionals, Dhaka, Bangladesh.
¹⁹ Institute of Water and Flood Management, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh.

Abstract

The principal nature-based solution for offsetting relative sea-level rise in the Ganges-Brahmaputra delta is the unabated delivery, dispersal, and deposition of the rivers' ~1 billion-tonne annual sediment load. Recent hydrological transport modeling suggests that strengthening monsoon precipitation in the 21st century could increase this sediment delivery 34-60%; yet other studies demonstrate that sediment could decline 15-80% if planned dams and river diversions are fully implemented. We validate these modeled ranges by developing a comprehensive field-based sediment budget that quantifies the supply of Ganges-Brahmaputra river sediment under varying Holocene climate conditions. Our data reveal natural responses in sediment supply comparable to previously modeled results and suggest that increased sediment delivery may be capable of offsetting accelerated sea-level rise. This prospect for a naturally sustained Ganges-Brahmaputra delta presents possibilities beyond the dystopian future often posed for this system, but the implementation of currently proposed dams and diversions would preclude such opportunities.

Abstract

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