Influence of Runoff from Upper Reaches of Yangtze River on Tidal Level at Tianshenggang Station

The forecast precision is low by using harmonic analysis method of tidal level prediction.The runoff from the upper reaches of the Yangtze River is the main factor influencing the forecast precision.In this paper,the upper runoff was analyzed.The results show that the error of tidal level prediction at the Tianshenggang Station grow with the difference of the corresponding discharge increasing.When the corre-sponding discharge is to zero,the error of tidal level prediction tends to zero too.When the corresponding discharge is same,the error de-creased with the increase of discharges.Symbol of the tide level’s error is contrary to the difference of the corresponding discharge.