Characteristics and Smoothing of Water Level Fluctuations in Dam Reservoirs

Abstract

Accurate predictions of inflows to dam reservoirs are the most important information for operations and managements. The water levels in the reservoirs are significantly influenced by wind and seiche resulting from gate operations and hence the computed inflow volumes are highly fluctuated with relatively large errors.The characteristics of fluctuations in water levels of reservoirs managed by Regional Hokkaido Development Bureau are practically clarified in this paper. The present study proposes a new smoothing method of fluctuated water levels in dam reservoirs, using Fourier analysis. The proposed method can easily be applied to the practical situations where the inflows are estimated with high accuracy.