Evaluating Forecasts in Reservoir Operations: The Role of Reforecast Products
Abstract
Forecasts of future weather can provide valuable information for reservoir operations. A challenge confronting reservoir operators today is whether to incorporate new climate products into their operations or to use historic data, perhaps Ensemble Streamflow Predictions (ESP), to guide them. This research evaluates the quality and value of forecasts generated from the Climate Forecast System version 2 (CFSv2) using the operations of Bear Lake, a multi-purpose reservoir owned by Pacific Corps, and compares it to the quality and value of using an ESP approach. Streamflow reforecasts are generated and used to evaluate the predictive skill of the CFSv2 in the context of decision making and reservoir operations. For the Bear Lake system, forecasts are most critical during the April through September period, when releases are being made for irrigation purposes. Snowpack data, available from April to June, are a determining factor in streamflow runoff during the later spring and early summer. The CFSv2 reforecast data makes use of this information and the approach used this research also uses snowpack data to select appropriate analog years in the ESP estimations. The streamflow forecasts are used as input for a decision support system. The decision support system for this study includes a simulation model that incorporates system constraints and operating policies. To determine the value of the reforecast products, performance metrics meaningful to managers are to be identified and quantified. Without such metrics and awareness of seasonal operational nuances, it is difficult to identify forecast improvements in meaningful ways. Some of the important operational metrics formulated for the Bear Lake Project are maximizing release irrigation allocations and reliably meeting set allocations. These metrics of system performance are compared for the reforecast, climatology, and observed scenarios to evaluate the potential benefits of using CFSv2 seasonal forecasts in systems decision making.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.H11K..08G
- Keywords:
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- 1808 HYDROLOGY Dams;
- 1807 HYDROLOGY Climate impacts;
- 1699 GLOBAL CHANGE General or miscellaneous