Risk evaluation of coastal erosin caused by Nankai megathrust earthquakes

2015 Fiscal Year Final Research Report

• Project/Area Number: 25750148
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: The University of Tokyo (2015); Chiba University (2013-2014)
• Principal Investigator: Obanawa Hiroyuki 東京大学, 工学(系)研究科(研究院), 特任研究員 (10422205)
• Research Collaborator: HAYAKAWA YUICHI 東京大学, 空間情報科学研究センター, 准教授 (70549443)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 海岸侵食 / 地盤沈下 / 南海トラフ / 地震

Outline of Final Research Achievements

Risk evaluation of coastal erosion caused by Nankai megathrust earthquake was carried out. Based on the historical records remarkable and cyclic land subsidence caused by mega earthquake occurred at Kochi coast up to 2 m and Shichiriohama up to 40 cm therefore those two areas were chosen for the study areas of this study. Calculation result with an existing equation for coastal erosion showed that 81 to 135 m erosion will occur at Kochi coast and 2 to 21 m erosion will occur at Shichiriohama after the mega earthquake. At Kochi coast 21% of the eroded area is building region and 11% of that is farm land where are residential and economic areas so direct damage by the coastal erosion will be relatively large. On the other hand at Shichiriohama large part (37%) of the eroded area is in the beach so the disaster damage will be relatively small.

Free Research Field

地形学