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Flows and sediment dynamics in the Ganga River under present and future climate scenarios

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journal contribution
posted on 2018-03-02, 14:46 authored by Sana Khan, Rajiv Sinha, Paul Whitehead, Sananda Sarkar, Li Jin, Martyn N. Futter

Identification of factors controlling sediment dynamics under natural flow regimes can establish a baseline for quantifying effects of present day hydrological alteration and future climate change on sediment delivery and associated flooding. The process-based INCA-Sediment model was used to simulate Ganga River sediment transport under baseline conditions and to quantify possible future changes using three contrasting climate scenarios. Construction of barrages and canals has significantly altered natural flow regimes, with profound consequences for sediment transport. Projected increases in future monsoonal precipitation will lead to higher peak flows, increasing flood frequency and greater water availability. Increased groundwater recharge during monsoon periods and greater rates of evaporation due to increased temperature complicate projections of water availability in non-monsoon periods. Rainfall and land surface interaction in high-relief areas drive uncertainties in Upper Ganga sediment loads. However, higher monsoonal peak flows will increase erosion and sediment delivery in western and lower reaches.

Funding

The research has been undertaken as part of two projects. First, the ESPA Deltas project “Assessing health, livelihoods, ecosystem services and poverty alleviation in populous deltas” [grant no. NE/J003085/1]. The project was funded by the UK Government’s Department for International Development (DfID), the Economic and Social Research Council (ESRC) and the Natural Environment Research Council (NERC) as part of the Ecosystem Services for Poverty Alleviation (ESPA) Programme. The second is the DECCMA Project “DEltas, Vulnerability and Climate Change: Migration and Adaptation” which is part of the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA), with financial support from DfID and the International Development Research Centre (IDRC), Canada.

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