Study on Abnormal Tidal Range Along Coast of Huangmaohai River Estuary:I-Theoritical Model

According to the statistic data of the hydrological almanac,the tidal range becomes diminished in the lower upstream of the Huangmaohai River estuary,and then enlarged in the further upstream.This phenomenon is very different from those of the other trumpet-like estuaries of the Pearl River.It is learnt from the harmonic analysis that this area is effected mainly by the M2 constituent.The tidal range variation in the estuary is consistent with the variation of the M2 constituent amplitude in the estuary.Three analytical models are employed to discuss the effects of river width,friction,and river depth on the tidal range.It is shown in the result that the abnormal tidal range along the upstrean of the Huangmaohai estuary is mainly caused by the effects of the river cross section area and the friction.