3:30 PM - 5:00 PM
[HDS10-P06] Investigation of Hydrogical Observation Method Focusing on Dissolved Gasses.
- comparison of physical properties and geological setting -
Keywords:Slope Failure, Hydrogical Observation, Dissolved Oxygen
Slope failures are often concentrated during the rainy season and typhoons. Landslides and rockfall, in particular, are thought to occur when the shear strength of soil decreases due to a rise in the groundwater table caused by rainfall and increased saturation in the soil layer, leading to collapse. Therefore, sediment disaster prone areas are designated by governments, and warnings and evacuation information are issued according to rainfall conditions.
However, slope failures also occur when there is no rainfall, and difficulty in predicting outbreaks makes evacuation and countermeasures difficult, and in many cases leads to extensive damage. Hence, the development of observation methods useful for collapse prediction is an urgent issue.
In this study, We focused hydrogical observations on dissolved oxygen in groundwater. The reason for that equipments have become available and more compact, in recent year, making field observations possible. We observed rainfall-induced fluctuations in dissolved oxygen in 2 different geological regions, pyroclastic plateau and accretionaly prism.
In pyroclastic plateau, alternative layers were identified, with welded tuff and tuff breccia. We velified multiple aquifers by groudwater level observation, but finally did not identify any clearly changes and direct variability in rainfall. On the other hand, on accretionaly prism, the response of dissolved oxygen to rainfall was observed, and a remarkable linkage with groundwater levels was observed. In conclusion, hydrogical observations of dissolved oxygen were not effective in both areas, but the results suggest that some geological features may be suitable for observation. In this presentation, we organize and present the results of observations in both regions.
However, slope failures also occur when there is no rainfall, and difficulty in predicting outbreaks makes evacuation and countermeasures difficult, and in many cases leads to extensive damage. Hence, the development of observation methods useful for collapse prediction is an urgent issue.
In this study, We focused hydrogical observations on dissolved oxygen in groundwater. The reason for that equipments have become available and more compact, in recent year, making field observations possible. We observed rainfall-induced fluctuations in dissolved oxygen in 2 different geological regions, pyroclastic plateau and accretionaly prism.
In pyroclastic plateau, alternative layers were identified, with welded tuff and tuff breccia. We velified multiple aquifers by groudwater level observation, but finally did not identify any clearly changes and direct variability in rainfall. On the other hand, on accretionaly prism, the response of dissolved oxygen to rainfall was observed, and a remarkable linkage with groundwater levels was observed. In conclusion, hydrogical observations of dissolved oxygen were not effective in both areas, but the results suggest that some geological features may be suitable for observation. In this presentation, we organize and present the results of observations in both regions.