Detailed observation of water level variation at the mouth of Natori River, Japan

In the present study, detailed measurement of water level variation is carried at the Natori River mouth in Miyagi Prefecture, Japan to find quantitative relationship between water level variation and river mouth morphology. For this purpose, the water level is measured with the interval of one minute, whereas conventional measurement system obtains data every one hour in general. It is observed that the water level inside and outside the river mouth shows distinct difference after the formation of sand spit at the river entrance, although the difference is not so remarkable after complete flushing of the spit during a flood.