感潮河段上游流量对潮位预报的影响

Influence of upstream discharge in tidal level prediction for tidal reaches

以长江口天生港站、徐六泾站、杨林站为例,基于大量样本建立了各站日均增水与大通流量增量之间的关系,并利用所得关系式,根据上游流量的大小,对潮汐预报模型计算的过去若干年的潮位进行校正.经过校正,3站日均潮位预报误差的绝对值≤20 cm的合格率分别由77.3%提高到92.1%,76.3%提高到88.7%,83.8%提高到89.2%.该方法也适用于其他感潮河段潮位的预报.

With Tianshenggang, Xuliujing and Yanglin tide stations in Changjiang Estuary taken as examples, the relationships between mean daily set-up of each station and discharge increment of Datong station were presented based on large samples. With the relationships, the tidal levels obtained by the tidal prediction model were corrected according to the upstream discharge. Taking 20 cm as error limit, the qualification ratios of predicted tidal level were raised to 92.1% from77.3% at Tianshenggang station, to 88.7% from 76.3% at Xuliujing station, and to 89.2% from 83.8% at Yanglin station, therefore, the forecasting accuracy was evidently improved. The present method is applicable to tidal level prediction for other tidal reaches.