Regional Estimation of the Heavy Rainfall Potential for PMP

Abstract

It is important to know the probable maximum precipitation (PMP) for a river basin. But unfortunately the PMP is presently not known in Japan. In other countries PMP is generally estimated for a meteorologically homogeneous region, but in geographically complex areas like most of Japan, it is difficult to determine these regions. This is because the wind field is affected by geographical features, and the atmospheric condition can make a large difference in relatively short distances. Therefore in this study, using a 3-D wind field simulation model, the atmospheric condition is estimated for a test case during an actual heavy rainfall. Finally using a 1-D convective cloud model, the regional heavy rainfall potential for a selected area is estimated.