Integrated Sediment Management for Catchments with Hydropower Dams:
Opportunity, Costs and Uncertainty
Reservoir sedimentation reduces storage capacity, which can have an impact on hydropower production, irrigation, flood control, and other benefits of dams and reservoirs. Both climate change and land use change can impact the rate of
reservoir sedimentation. Reservoir storage capacity loss due to sedimentation, however, can be reduced through integrated catchment and river sediment management. Implementation of integrated sediment management plans for catchments with hydropower dams requires an understanding of uncertainty in future climate, land use, and sediment predictions. Sediment predictions that are provided without addressing the associated range of potential changes could mislead the selection of sediment management strategies and associated costs. Quantifying the uncertainty in sediment predictions and its implication for the opportunity and cost of integrated sediment management for catchments with hydropower dams is especially important in regions undergoing rapid dam development such as the Mekong River Basin. Hence the main objective of this research is to quantify the uncertainty in sediment predictions –due to land use change, future climates and simulation model– and its implication for the opportunity and cost of integrated sediment management for catchments with hydropower dams. The 3S basins of the Lower Mekong River Basin will be used as a case study. Uncertainty in land use change will be evaluated using an ensemble forecasting (i.e using different initial conditions, boundary conditions, parameterizations, input data and models). Uncertainty in future climates will be addressed using multiple, statistically downscaled, general circulation models (GCMs), greenhouse gas emissions scenarios (GHGES) and climate sensitivity settings. Simulation model uncertainty will be analyzed by calibrating the sediment and flow prediction model(s) using different optimal objective functions. The implication of these uncertainties for the opportunity and cost of integrated sediment management for catchments with hydropower dams will be assessed using appropriate sediment management models and cost models. The research outcomes are expected to contribute to the understanding of the magnitude of uncertainties related to land use change, climate change and sediment modelling and their implication for the opportunity and cost of integrated sediment management for catchments with hydropower dams.
Related presentations and publications
Shrestha, B., Cochrane, T.A., Caruso, B.S., Arias, M.E., and Piman, T. (2016). Uncertainty in flow and sediment projections in the Mekong River Basin dominated by land use conversions. San Francisco, USA: American Geophysical Union (AGU) Fall meeting 2016, 12 - 16 Dec 2016.
Shrestha, B., Cochrane, T.A., Caruso, B.S., and Arias, M.E., (2016). How does uncertainty in land use change influence flow and sediment projections? Queenstown, New Zealand: New Zealand Hydrological Society and Australian Hydrology and Water Resources Symposium, 28 Nov - 2 Dec 2016.
Shrestha, B., Cochrane, T.A., Caruso, B.S., Arias, M.E. and Piman, T. (2016) Uncertainty in flow and sediment projections due to future climate scenarios for the 3S Rivers in the Mekong Basin. Journal of Hydrology 540: 1088–1104. http://dx.doi.org/10.1016/j.jhydrol.2016.07.019.
Shrestha, B. and Cochrane, T.A. (2016) How does catchment model parametrization and climate change influence uncertainty in flow and sediment projections? A case study of a key tributary basin of the Mekong River. Wellington, New Zealand: Water NZ modelling symposium, 16-17 Mar 2016.
Shrestha, B. and Cochrane, T.A. (2016) The Influence of Land Use Projection Uncertainty on Flow and Sediment Estimations: A Case Study from the Mekong Basin. Purdue University, West Lafayette, IN, USA: 10th International Symposium on Agriculture and the Environment, 23-26 May 2016.