Rapid Reservoir Storage–Based Benefit Calculations

Abstract

Reservoir management strategy optimization requires benefit calculations based on reservoir storage, which is variable because of sedimentation. It is therefore necessary to express reservoir benefits as a function of reservoir storage. For planning purposes, a need for rapid benefit calculation techniques often exists. Such a calculation model is developed in this paper, quantifying annual water supply, power generation, and flood control benefits as a function of reservoir storage. The calculation model sets up a relationship among reservoir storage, reliability, water inflow, and flood characteristics and annual average water supply, power generation, and flood control benefits. The Gould-Dincer approach is adopted to calculate annual average water supply and storage hydropower generation benefits and relate them to reservoir storage and reliability. The property damage avoided (PDA) method is used to quantify annual average flood control benefits. The results obtained using the rapid assessment technique are compared to those obtained from other more detailed quantification methods executed for a number of power generation scenarios for the Three Gorges Reservoir, and are found to be of satisfactory calculation accuracy for planning purposes. Because of the lack of data, the annual average flood control benefit calculation method was tested for the Three Gorges Reservoir with assumed flood loss data, illustrating the flood control benefit at different flood storages.