昭和63年7月豪雨時の降雨量に対する確率評価

The western parts of Simane Prefecture suffered severe disasters from slope and flood flows caused by record heavy rainfall, in July 15, 1988.
At the Hamada meteorological observatory, for instance, the maximum one-day and one-hour rainfalls were 331.5mm and 90.0mm, respectiyely. After delivering the amount of rainfall during the localized heavy rainfall, this paper discusses the annual extreme probability for the anual maximum values of 10 minutes, one-hour, and one-day rainfall in Hamada and Mastue District. In the hydrologic frequency analysis, it is assumed that these annual maximum values follow the 3-parameter log-normal distribution. As the results, for example, the historical maximum one-day rainfall at Hamada(394.5mm) is evaluated as 176-years probable values by means of frequency analysis.