径流的河口潮位预报方法研究

Improved Prediction of Tidal Level at Estuary Considering Runoffs

河口地区潮位受上游洪水渡和下游潮波的共同影响,综合考虑两者的作用是提高预报精度的关键。本文以长江口天生港、徐六泾、杨林站为例,根据大量样本资料,建立了各站的日均增水与大通径流增量之间的关系,并利用所得关系式,根据上游径流大小,对潮汐预报的潮位进行校正。经过校正,三站日均潮位误差(+20cm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%,最终的潮位预报精度明显提高。

Tidal level at estuary is affected by interaction between flood wave from upstream and tidal wave from downstream. How to take the interaction of those two factors is the key to improve prediction accuracy. This paper quotes Tiansheng station, Xuliujing station and Yanglin station at estuary as examples and establishes a relationship between daily water increase and runoff increase figure based on sufficient sampling data. The relationship is used to adjust predicted tidal level on assumption of runoff figure from upstream. After this adjustment, passing rate of daily tidal level prediction tolerance less than 20cm for above - mentioned three reference stations is improved from 77. 3% to 92. 1, 76. 3% to 88. 7% , 83. 8% to 89. 2% respectively. In a word, tidal level prediction accuracy is significantly improved eventually.