Host: The Association of Japanese Geographers
Name : Annual Meeting of the Association of Japanese Geographers, Spring 2024
Date : March 19, 2024 - March 21, 2024
This is the second report of "Extraction of aspect ratio of band-shaped heavy rainfall area using directional variogram," which was presented by the authors at The General Meeting of the AJG autumn 2023. In the previous presentation, we proposed a method for extracting the aspect ratio of band-shaped heavy rainfall area using directional variograms, focusing on the value of aspect ratio of 2.5 or higher, which is one of the criteria for the release of "Information on Significant Heavy Rainfall," which the Japan Meteorological Agency (JMA) started to release in June 2021.In this presentation, we set precipitation thresholds and calculated directional variograms for 17 cases for which "Information on Significant Heavy Rainfall" was released in 2022. As a result, when the precipitation threshold was set at 80 mm/3 h, the value was closest to the value announced by the JMA. However, even with the threshold set, there were cases in which the values were lower than the values announced by JMA because of a precipitation system separated from the band-shaped heavy rainfall area. This suggests that a quantitative study of the coverage area is an issue to be addressed in the future.
