A first look at the influence of anthropogenic climate change on the future delivery of fluvial sediment to the Ganges–Brahmaputra–Meghna delta

Darby, Stephen E.; Dunn, Frances; Nicholls, Robert J.; Rahman, Md. Mostafizur; Riddy, Liam

doi:10.1039/c5em00252d

Cited by 50 publications

(51 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, our results are comparable to estimates by Darby et al (2015) who reported increases of 52-60 % in total sediment load for the end of the century compared to 1981-2000. Their estimates were derived from precipitation and temperature data downscaled from several Regional Climate Model simulations for the SRES A1B.…”

Section: Discussionsupporting

confidence: 88%

“…Below follows a synthesis of present state parameter values (of parameters 1-6 in Table 1A (Islam et al 1999;Darby et al 2015;Ray et al 2015;Prasch et al 2015). 2.…”

Section: Synthesis Of Reported Parameter Values: Present Statementioning

confidence: 99%

“…5. Manning's roughness coefficient The Institute of Water Modelling Bangladesh hosts bathymetric cross section information and discharge data of the river reach Minimum and maximum reported values Darby et al (2015) and Masood et al (2015) (a) Running mean values of several days were used in the modelling; the given base mode range reflects the interval of this running mean over a year. The monthly coefficient of variation (CV) of column 3 reflects a variation around this mean due to fluctuating daily values, which we use to define lower bound and upper bound deviations (column 2) (b) Not used in the sensitivity analysis Present to future sediment transport of the Brahmaputra River: reducing uncertainty in… 519 located in Bangladesh.…”

Section: Synthesis Of Reported Parameter Values: Present Statementioning

confidence: 99%

“…For the end of the century (2075-2100), projected increases in air temperatures within the basin range from 2.3°C (Immerzeel 2008) to 4.8°C (Darby et al 2015;Masood et al 2015; Table 1B) relative to their respective reference periods within the years 1960 to 2000. Reported projections of future discharges of the Brahmaputra River span a wide range, in part because even current conditions are uncertain (Nepal and Shrestha 2015).…”

Section: Synthesis Of Reported Parameter Values: Future Statementioning

confidence: 99%

“…By the end of the century, however, both mean and extreme discharges are consistently projected to increase in the low-lying Brahmaputra (Gain et al 2011). Estimates for Bangladesh due to projected increases in precipitation range between increases of 13 % (Masood et al 2015) up to 39 % (Darby et al 2015), compared to their respective reference periods both within the years 1980-2000 (Table 1B). These projected long-term average discharge increases are also consistent with the synthesis of climate model run-off projections in the latest IPCC report (Collins et al 2013).…”

Section: Synthesis Of Reported Parameter Values: Future Statementioning

confidence: 99%

See 4 more Smart Citations

Present to future sediment transport of the Brahmaputra River: reducing uncertainty in predictions and management

et al. 2016

View full text Add to dashboard Cite

The Brahmaputra River in South Asia carries one of the world's highest sediment loads, and the sediment transport dynamics strongly affect the region's ecology and agriculture. However, present understanding of sediment conditions and dynamics is hindered by limited access to hydrological and geomorphological data, which impacts predictive models needed in management. We here synthesize reported peer-reviewed data relevant to sediment transport and perform a sensitivity analysis to identify sensitive and uncertain parameters, using the one-dimensional model HEC-RAS, considering both present and future climatic conditions. Results showed that there is considerable uncertainty in openly available estimates (260-720 Mt yr -1 ) of the annual sediment load for the Brahmaputra River at its downstream Bahadurabad gauging station (Bangladesh). This may aggravate scientific impact studies of planned power plant and reservoir construction in the region, as well as more general effects of ongoing land use change and climate change. We found that data scarcity on sediment grain size distribution, water discharge, and Manning's roughness coefficient had the strongest controls on the modelled sediment load. However, despite uncertainty in absolute loads, we showed that predicted relative changes, including a future increase in sediment load by about 40 % at Bahadurabad by 2075-2100, were consistent across multiple model simulations. Nevertheless, for the future scenarios we found that parameter uncertainty almost doubled for water discharge and river geometry, highlighting that improved information on these parameters could greatly advance the abilities to predict and manage current and future sediment dynamics in the Brahmaputra river basin.

show abstract

Section: Discussionsupporting

confidence: 88%

“…Below follows a synthesis of present state parameter values (of parameters 1-6 in Table 1A (Islam et al 1999;Darby et al 2015;Ray et al 2015;Prasch et al 2015). 2.…”

Section: Synthesis Of Reported Parameter Values: Present Statementioning

confidence: 99%

Section: Synthesis Of Reported Parameter Values: Present Statementioning

confidence: 99%

Section: Synthesis Of Reported Parameter Values: Future Statementioning

confidence: 99%

Section: Synthesis Of Reported Parameter Values: Future Statementioning

confidence: 99%

See 3 more Smart Citations

Present to future sediment transport of the Brahmaputra River: reducing uncertainty in predictions and management

et al. 2016

View full text Add to dashboard Cite

show abstract

Sediment Yields and Sediment Budgets

Walling¹

2019

Encyclopedia of Water

View full text Add to dashboard Cite

This article aims to provide a broad overview of the topic across spatial scales ranging from small catchments to a global perspective. The two elements of the topic (i.e. sediment yields and sediment budgets) are closely related, with the former treating the catchment or river basin essentially as a black box. The latter looks into the black box to consider the importance of sediment sources, and sediment mobilization, transport, and storage in influencing sediment yields. Attention is directed firstly to the key features of sediment yields, by considering fluvial sediment loads, measurement techniques, the magnitude of sediment yields, and associated global and regional patterns and key controlling factors. Information on spatial variability of sediment yields is complemented by consideration of medium‐ and longer‐term temporal variability in response to natural factors and, more importantly, the impact of anthropogenic activity and climate change. Sediment budgets are introduced by considering the important role of internal storage in influencing the sediment yield from a catchment or river basin and the concepts of the sediment delivery ratio and connectivity, as well the need to take account of the sediment sources involved. Examples of sediment budgets are provided and available techniques for assembling the information necessary to establish a sediment budget are reviewed.

show abstract

Morphotectonic forcing and anthropogenic impact behind a recently emerged relict island of the Brahmaputra River

Gogoi

Chetia

Borgohain

et al. 2022

Earth Surf Processes Landf

View full text Add to dashboard Cite

Large rivers can be significantly impacted upon by both tectonics and human activities; yet, there are very few studies where these natural and anthropogenic impacts combine. A new river island called Dibru-Saikhoa has appeared very recently on the Brahmaputra valley map in Assam. More than 200 km 2 in area, it is situated in the extreme upstream reach of the Brahmaputra River and represents the second biggest relict island after Majuli (with a present area of $500 km 2 ). The cause of the formation of this island is generally attributed to river dynamics, with only a minor anthropogenic role. However, our study, considering morphological changes from 1915 to 2019 and subsurface geophysical data, suggests that the anthropogenic factor was an important 'trigger' of island formation, acting on a system made sensitive to change by the combination of local tectonics and rapidly changing sediment influx.Making use of the satellite-borne Bouguer gravity data and ground survey-based seismic sections, we located some of the prominent blind faults. Taking into consideration recent activation and interplay of these faults, the mode of accommodation space generation, and aggradation characteristics due to fluvial processes, we suggest a multi-order mechanism of formation of this relict island. The first-order trigger is due to the unstable river morphology of the Siang, which is responding to tilting of the valley floor as a co-seismic phenomenon, and subsequently influences two other rivers-the Dibang and the Lohit. Second-order forcing comes from intra-plate residual pop-up that comes into play due to uneven sediment loading. The third-order forcing is inter-plate suturing, which causes arching and fracturing of the basement.

show abstract

A first look at the influence of anthropogenic climate change on the future delivery of fluvial sediment to the Ganges–Brahmaputra–Meghna delta

Cited by 50 publications

References 46 publications

Present to future sediment transport of the Brahmaputra River: reducing uncertainty in predictions and management

Present to future sediment transport of the Brahmaputra River: reducing uncertainty in predictions and management

Sediment Yields and Sediment Budgets

Morphotectonic forcing and anthropogenic impact behind a recently emerged relict island of the Brahmaputra River

Contact Info

Product

Resources

About