2020 Fiscal Year Final Research Report

Doppler lidar observation of wind profile under cumulus convection for establishing a state-of-the-art wind hazard

Research Project

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Project/Area Number	18H03805
Research Category	Grant-in-Aid for Scientific Research (A)
Allocation Type	Single-year Grants
Section	一般
Review Section	Medium-sized Section 23:Architecture, building engineering, and related fields
Research Institution	Kyoto University
Principal Investigator	MARUYAMA TAKASHI 京都大学, 防災研究所, 教授 (00190570)
Co-Investigator(Kenkyū-buntansha)	竹見哲也京都大学, 防災研究所, 准教授 (10314361) 山田広幸琉球大学, 理学部, 准教授 (30421879) 山口弘誠京都大学, 防災研究所, 准教授 (90551383)
Project Period (FY)	2018-04-01 – 2021-03-31
Keywords	ドップラーライダー / 立体的フィールド観測 / 強風ハザード / 積雲対流 / 突風 / 境界層 / レーダー観測 / 強風被害
Outline of Final Research Achievements	Field observation of wind profile near the ground has been carried out by using a doppler lidar and meteorological radars. Characteristics of fluctuational wind under cumulus convection and the growth of boundary layer including not only the effect of ground friction caused by surface roughness but also the effect of gust caused by up/down draft was examined and clarified. The calculation method was constructed to simulate and to predict the flow fields in the boundary layer under cumulus convection. The boundary condition was downscaling from meteorological model WRF. The surface roughness was obtained from GIS and evaluated by the canopy model. The transport equation of temperature and the cloud-resolving model was used resulting that the up/down draft was generated under the cumulus convection. The parameter study on the fluctuational wind has been carried out and obtained the characteristics of the wind flow contributing to establishing a state-of-the-art wind hazard.
Free Research Field	建築耐風構造
Academic Significance and Societal Importance of the Research Achievements	建物被害の原因となる強風特性に関して、これまで地表面摩擦に起因する「風の乱れ」だけが考慮されてきたが、ダウンバーストや竜巻、ガストフロントなど局所的ではあるが激甚な建物被害を引き起こす極端気象現象が明らかになるにつれ、これら積雲対流下の上昇・下降気流に由来する風速の急変を伴う「突風」を考慮した「新たな強風ハザード」が求められている。本研究は、地表面摩擦による「風の乱れ」だけでなく、積雲対流による「突風」の影響を予測・評価できる変動風速場の解析手法を構築し、これにより、最大瞬間風速も評価できる「新たな強風ハザード」の提案に資するデータを得、強風建物被害の低減に貢献するものである。