Abstract
On the 11th of Sep. 1937, a typhoon caused moderate flooding damage along the northern and NE-ern coasts of the Oosaka bay and the northern coasts of Harima-Nada (Sea). The author, as was investigated by Mr. T. Hirono and K. Sakata, has tried to find some relations between the height of sea level and the meteorological elements by using the observational data.
The high water is investigated in two cases, the one (a) for increasing stage and the other (b) for decreasing one.
The equations showing the relation between the meteorological elements and the elevation of sea level for the increasing stage are as follows;-
where A is abnormal elevation of water level (cm), P atmospheric pressure (mm), V and υ SW-component of wind velocity at the Oosaka harbour and at the air port of Kizugawaziri respectively, and W S-component of the wind velocity over the Kii channel before two hours. Figures in brackets show probable errors. For the decreasing stage, ΔA=-47.83+3.37ΔV-1.32 ΔP (±6.3) ΔA=-47.60+4.74Δυ-1.32 ΔP (±7.4)…(b)
where ΔA is the diminution of water level (cm) from its greatest value, ΔV, Δυ the deviation of V, υ from the value observed when the greatest height of sea level occurred, and ΔP that of pressure. In those equations, it is considered after Wadati's idea that the rise of the sea level in the Oosaka bay depends greatly upon the S-erly wind blowing over the Kii channel. Equations (b) shows that the height of sea level diminished quickly about 48cm during one hour just after its maximum, and then decreased linearly by and by according as the wind weakened. This is perhaps due to the slope current occurred instantaneously after the sea level attained the greatest height. From the results of (a) group, we can see that the rate of inflow current (U0) occurred then through the Kitan straights is obtained as U0=0.00448 W(m/s), assuming the uniform velocity with depth and consequently considering theoretical results between the wind and the drift current velocity, we get a=0.0013 as the extinction coefficient of the current velocity with depth. Lastly the author expresses his best thanks to Dr. Wadati for his kind guidance for this investigation.
