Effect of typhoon frequency on landslide magnitude-frequency and sediment yield in temperate-humid and tectonically active region

2014 Fiscal Year Final Research Report

• Project/Area Number: 25882037
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Geography
• Research Institution: Kanto Gakuin University
• Principal Investigator: SAITO Hitoshi 関東学院大学, 経済学部, 講師 (00709628)
• Project Period (FY): 2013-08-30 – 2015-03-31
• Keywords: 湿潤変動帯 / 斜面崩壊 / 規模－頻度 / 土砂災害 / 台風 / 地理情報システム（GIS） / 降雨量 / 侵食量

Outline of Final Research Achievements

A catalogue of 4,744 recent landslides associated with rainfall events throughout Japan indicates that large landslides dominated the volumetric budget when total rainfall, maximum rainfall intensity, and mean rainfall intensity exceeded ~250 mm, ~35 mm/h, and ~4 mm/h, respectively. However, neither the most frequent nor the most extreme rainfall parameters triggered the highest landslide volumes consistently. Instead, the maximum of volumetric landslide production may largely be tied to comparatively rare typhoons. Only rainfall totals appear to be a suitable predictor of landslide volumes mobilized during typhoons and frontal storms. Our results pinpoint rainfall thresholds that triggered the highest frequency and the highest total volume of landslides in Japan with average return periods of <40 yr （Saito et al., 2014, Geology）.

Free Research Field

自然地理学