Landslide risk characterization using integrated wireless sensor network system for point and area-averaged measurements

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06299
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41030:Rural environmental engineering and planning-related
• Research Institution: Saga University
• Principal Investigator: MIYAMOTO HIDEKI 佐賀大学, 農学部, 准教授 (10423584)
• Co-Investigator(Kenkyū-buntansha): 中村 真也 琉球大学, 農学部, 教授 (30336359)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 土壌水分量 / COSMOS / 熱外中性子 / 土壌水分・加速度センサ / 斜面

Outline of Final Research Achievements

We employed the COsmic-ray Soil Moisture Observing System (COSMOS) to monitor temporal changes in epithermal neutron count on hillslope. The number of epithermal neutrons was corrected for atmospheric pressure, absolute humidity, and background neutron count hourly. The corrected hourly count of epithermal neutrons (N) indicated substantial variability and no discernible correlation with the volumetric water content (θ) and measured by soil moisture sensors at three different depths (10 cm, 30 cm, and 50 cm) in proximity to COSMOS. However, the daily or half daily mean of N exhibited a clear negative association with θ at a depth of 10 cm. These findings suggest that COSMOS can effectively monitor changes in the daily or the half daily mean of θin surface soils on hillslope.

Free Research Field

農業農村工学

Academic Significance and Societal Importance of the Research Achievements

①COSMOSによる斜面の熱外中性子観測を通して，土壌水分センサで測定した体積含水率と中性子数との関係を見出したうえで，点水分量と面水分量の挙動の差異を明らかにしたことにより，観測スケールの異なる2つの手法を組み合せて利用することの有用性を示すことができた。
②点水分量および面水分量に加え，斜面内部の加速度データを測定することによって，降雨を誘因とする土砂災害の早期検知やリアルタイム危険度評価の実現可能性を示し，データ駆動型減災技術の社会実装の方途を示した。