NUMERICAL EXPERIMENT ON THE RELATIONSHIP BETWEEN THE FORM OF TOPOGRAPHY AND THE FIELDS OF PRECIPITATION AND WIND VELOCITY IN LINEAR CONVECTIVE SYSTEMS

The current study conducted some investigations into the relationship between the form of topography and the fields of precipitation and wind velocity in linear convective systems, through a physically-based numerical approach using a mesoscale meteorological model with virtually-created atmospheric conditions. In order to clarify the mechanism of localized torrential precipitation, sensibility analysis of precipitation systems was conducted by modifying the form of topography at the point where convective cells were mainly generated by orographic trigger effects. The results show that the modification of topography tends to affect the organization of convective cells, which leads to the formation of a linear convective system. Areal maximum precipitation from a linear convective system largely fluctuates by around ±20 % with the modification of topography and can be decreased in some cases as the topographic elevation increases, although areal average precipitation shows a slight change of -5 to 5 %. A streamline analysis of the wind field shows that the decrease of maximum precipitation can be attributed to greater temporal fluctuations of the wind field caused by the modification of topography.