PRECIPITATION ANALYSIS OF HEAVY RAINFALLS IN AICHI PREFECTURE USING 10-MINUTE PRECIPITATION DATA

Abstract

Precipitation analysis for heavy rainfalls in Tokai district on September 11-12, 2000 and August 28-29, 2008 was performed based on 10-minute precipitation data. Rainfall distribution analyses showed that a rain band in the direction of the prevailing wind at middle levels slowly moved eastward on the western Aichi Prefecture throughout the both events. The rain band consisted of aligned heavy-rain cells of about 5-10 km diameter that traveled successively along the rain band. The band lay 10-20 km toward the cold sector of a meso-scale convergence line. Moreover, an analysis of 10-minute precipitation data for the past 22 years revealed that the areas including the northern Chita Peninsula and Nagoya City have a maximum frequency of heavy rain of short duration despite having the lowest annual total precipitation in Aichi Prefecture. Thus, these areas seem to have topographic characters favoring concentrated heavy rainfall only under specific meteorological conditions.