Prediction Accuracy of Precipitation And Practicability of Anticipatory Release Operation Policy

Abstract

Anticipatory release operation against floods for multi-purpose reservoirs was proposed as a vehicle to incorporate the recent remarkable progress of precipitation forecasting techniques into better utilization of available reservoir storage.
The accuracy of precipitation forecasts was expressed by a set of standard deviations of absolute or relative prediction errors, σ_s, σ_e, σ₁ and σ₁ * that are respectively for the time that precipitation starts, the time that ends, differences between successive precipitation forecasts and differences of realized precipitation from the immediately preceeding prediction.
Numerical simulation was conducted for a hypothetical two-reservoir system of a typical scale, which revealed that the anticipatory release operation brings about an extra efficiency and reliability to the reservoir system by reducing flood damages of which the magnitude depends on the accuracy of precipitation forecasts. This is equivalent to the increase of an extra storage to the system.