豪雨の生起・発達に地形が及ぼす影響に関する数値実験的研究

Abstract

The mechanism of orographic convective local heavy rainfall, which is effected by mountainous topography, has been investigated numerically using the non- parameterised cumulus model expressing bottom topography. To express bottom topography, coordinate transformation and tensor analysis are used. Through simulation of the convective rainfall using the model, the physical mechanism of the effect of mountainous topography on the cumulus is clearly understood. The followings are the knowledge of the mechanism that is obtained by this study(1) topography which is lower than bottom of a cloud plays a role as a trigger of convection and has no effect on processes of cloud development, (2) topography which is higher than bottom of cloud take an effect of to the process of cloud development, (3) effects of higher mountains depends on the horizontal scale of mountain, speed of advection and speed of development of cumulus.