Research project on rainfall characteristics and prediction of localized intense rainfall in urban area based on rain particle measurements and high density meteorological observations

2015 Fiscal Year Final Research Report

• Project/Area Number: 24300320
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Geography
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Takahashi Hideo 首都大学東京, 都市環境科学研究科, 教授 (40202155)
• Co-Investigator(Kenkyū-buntansha): MIKAMI Takehiko 帝京大学, 文学部, 特任教授 (10114662) ; SAKAIDA Kiyotaka 東北大学, 環境科学研究科, 教授 (10133927) ; SAWADA Yasunori 東京学芸大学, 教育学部, 准教授 (60510667)
• Research Collaborator: YOKOYAMA Hitoshi ; SETO Yoshihito
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 短時間強雨 / 都市域 / 降水特性 / 降水粒子 / 稠密気象観測 / 収束 / 予測 / 東京

Outline of Final Research Achievements

This research project was conducted to clarify the characteristic features of localized intense rainfall (LIR) in urban area based on observation data of rain particles, high density rain-gauge networks and radar, and to examine the prediction method of LIR by using high density meteorological observations. In the beginning phase of LIR, ratio of large rain particles was high, and rainfall intensity increased rapidly. Spatially concentrated and small scale intense rainfall areas appeared frequently in the region from the northern part of Metropolitan Tokyo to the southern part of Saitama Prefecture. As for the diurnal variation in LIR frequencies, two major peaks were observed about 4 PM and 10 PM in the western part of Tokyo Wards area. From statistical analyses of many LIR cases, it was confirmed that the increase in convergence of surface winds from 40-50 minutes before the beginning of LIR is an effective signal for the prediction of LIR occurrence.

Free Research Field

気候学