[H-DS10] Geohazards in humid, tectonically active countries and their precursors

[HDS10-08] Evaluation of the slope displacement and potential risk of a sediment disaster at Kiyomizu-dera Temple area

*Masamitsu Fujimoto¹, Toru Danjo², Kenichiro Toda³, Masayuki Ujihara⁴, Yoshifumi Satofuka¹, Ryoichi Fukagawa¹ (1.Ritsumeikan University, 2.National Research Institute for Earth Science and Disaster Resilience, 3.Geo Forest Co.,Ltd, 4.Nittoc Construction Co.,Ltd)

To evaluate the potential risk of sediment disasters at Kiyomizu-dera Temple, we investigated the spatial distribution of springs based on a topographical analysis using a Curvature and Slope (CS) topographical map. The study area was divided into two areas, erosion and non-erosion, divided by a fault line. We observed springs with small slope collapse at numerous points in the erosion area. Our results suggest deep infiltration of groundwater in the non-erosion area, and exfiltration of groundwater in the erosion area, leading to the occurrence of slope collapse. In addition, we installed a field monitoring system on a slope behind a culturally important building to measure surface displacement to 1.0 m depth using inclinometer sensors. Our results suggest that a slip surface formed at GL-0.6 to -1.0 m. The relationship between rainfall and maximum displacement indicated the coefficient of determination with the highest relationship between hourly rainfall and maximum displacement.