Research to extract slopes with risk of landslides, using the LiDAR data measured before and after a hazard.

2013 Fiscal Year Final Research Report

• Project/Area Number: 24658146
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Forest science
• Research Institution: Forestry and Forest Products Research Institute
• Principal Investigator: MURAKAMI Wataru 独立行政法人森林総合研究所, 水土保全研究領域, 主任研究員 (10353880)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Keywords: 岩手宮城内陸地震 / 航空レーザー測量 / 斜面変形 / 亀裂 / 崩壊

Research Abstract

I compared the hillshade and contour maps, using the LiDAR data measured before and after the Iwate-Miyagi Nairiku Earthquake occurred on June 18, 2008. And, I have extracted the site where the transformation is confirmed to the slope. On these slopes, the occurrence of cracks was confirmed by the field survey. On these slopes, I did the soil exploration. As a result, it was confirmed that a weathering thick layer (N-value is less than 20) existed in these slopes and a weak layer (N-value is less than 10) existed between weathering layers. In addition, I calculated the return periods of rainfall and the soil water index on the basis of the AMeDAS data near the study area. As a result, it was confirmed that the possibility of landslide occurrence was low in the rainfall after the earthquake. Therefore, it was guessed that the possibility of landslide occurrence according to rainfall after the earthquake was relatively high in these slopes.