Development of a new shallow landslide prediction model incorporating the effect of water flow through bedrock layers

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02392
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 25030:Disaster prevention engineering-related
• Research Institution: Hokkaido University
• Principal Investigator: KATSURA Shin'ya 北海道大学, 農学研究院, 助教 (40504220)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 基岩層 / 水移動 / 表層崩壊

Outline of Final Research Achievements

The currently widely used shallow landslide prediction models do not take into account the effect of water flow through bedrock layers. In this study, detailed field observations in a small mountain basin clarified the effect of runoff of bedrock groundwater on the spatiotemporal variation of the groundwater level in the soil layers. In addition, by measuring the hydraulic properties characterizing water movement in soil and bedrock layers, and by combining seepage flow analysis including bedrock layers and slope stability analysis, a new shallow landslide prediction model that incorporates water movement through bedrock layers was developed.

Free Research Field

砂防学

Academic Significance and Societal Importance of the Research Achievements

本研究により，基岩層内の地下水が土層に流出し，土層内の地下水位の時空間変動に影響を与えていることが明らかとなり，基岩層を介した水移動を組み込んだ新たな表層崩壊予測モデルを開発することができた。本モデルの精度を向上させるためには，基岩層内に存在する亀裂の影響を明らかにし，モデルに組み込んでいく必要があることが分かった。こうした点をクリアできれば，表層崩壊の発生場所やタイミングをより精度よく予測し，警戒避難等の適切な対策を実施することで被害を防止・軽減することが可能となる。