抄録
We focus on the Probable Maximum Precipitation (PMP) over the Upper Tone River basin, through weather conditions change. In order to evaluate total amount and distributions of heavy rainfalls, WRF model is used. The results are summarized as follows: (1) Temporal rainfall distribution change by relative humidity modification has a different characteristics depending on the rainfall type (typhoons and/or fronts). (2)In the case of typhoons, an increase of relative humidity affects not only total rainfall but also its temporal variation. (3) Moisture fluxes show high correlation with total and 12 to 72-hour rainfalls through WRF model calculation in the basin, which clearly suggests they can be used as a suitable parameter to estimate PMP. (4) PMP is calculated from the past maximized moisture flux in 12 , 24, and 72-hour rainfall durations.