GCM-related uncertainty in river flow projections at the threshold for “dangerous” climate change: the Kalu Ganga river,Sri Lanka |
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| Authors: | Leander Schulz |
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| Institution: | Department of Geography, University of Otago, Dunedin, New Zealand |
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| Abstract: | The Kalu Ganga catchment is one of the largest in Sri Lanka, and is home to 5% of the national population. A first assessment is provided here of the sensitivity of Kalu Ganga runoff to a 2°C increase in global mean temperature – the supposed threshold for “dangerous” climate change. Runoff is simulated using the HBV-Light hydrological model and scenario data from seven general circulation models (GCMs). Precipitation is the strongest cause of change in runoff. Substantial inter-GCM differences in scenario precipitation lead to uncertainty in the direction of change in mean annual runoff from the baseline (range ?25% to +19%). Scenario monthly runoff ranges from ?41% to +124% of the baseline values at its most extreme (March); June is the only month with a consistent direction of change (range ?17% to ?65%) – thus indicating that climate change may lead to a substantially different hydrological regime in the Kalu Ganga catchment. |
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| Keywords: | climate change river runoff hydrological modelling uncertainty Sri Lanka |
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