Saline intrusion in the Ganges-Brahmaputra-Meghna megadelta

Bricheno, Lucy M. ORCID: https://orcid.org/0000-0002-4751-9366; Wolf, Judith ORCID: https://orcid.org/0000-0003-4129-8221; Sun, Yujuan ORCID: https://orcid.org/0000-0002-7861-9124. 2021 Saline intrusion in the Ganges-Brahmaputra-Meghna megadelta. Estuarine, Coastal and Shelf Science, 252, 107246. 10.1016/j.ecss.2021.107246

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Official URL: http://dx.doi.org/10.1016/j.ecss.2021.107246

Abstract/Summary

In the fertile Ganges-Brahmaputra-Meghna (GBM) delta, which spans the boundary from West Bengal in India and Bangladesh, the availability of freshwater is crucial to subsistence livelihoods and protected ecosystems. Controlled by large tides and widely variable river discharge, the delta experiences rising river salinity and salt intrusion, as well as seasonal flooding during the monsoon. Future climate change is projected to increase rainfall in South Asia and river discharge in the GBM system. We address how this process might combine with sea-level rise (SLR) to control future river salinity. Model experiments designed using a range of SLR and climate change scenarios are performed to investigate the forces controlling river salinity in the delta. A flexible mesh modelling approach allows us to investigate the impacts at a wide range of time and space scales. In future projections the disparity between wet and dry season salt intrusion intensifies. In the future, SLR acts to increase river salinity in the GBM delta. During the dry season, this effect is worsened by reduced river discharge. In the wet season, this can be mitigated in the eastern part of the delta by larger seasonal river flows. The central and western delta is dominated by SLR, leading to increased salt intrusion all year round, impacting on water resources and agricultural productivity. In the context of an intensifying hydrological cycle, these conclusions have implications for similar tide-dominated deltas, where SLR can increase tidal range, and therefore exacerbate salt intrusion.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1016/j.ecss.2021.107246
ISSN:	02727714
Date made live:	11 Mar 2021 13:07 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/529882

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1016/j.ecss.2021.107246

ISSN:

02727714

Date made live:

11 Mar 2021 13:07 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/529882