Fig. 2

Topographic and geological information of the study area (a) Elevation. b Slope angle. c Slope aspect. d Geological map (based on the 1:200,000 seamless geological map published by the Geological Survey of Japan, AIST). The detailed explanations of the geological codes (N2sn, N3sn, Hsr, Q2th, N1 sr, Q2sr and Q3tl) are listed in Table 1