Fig. 2.
The panels present stages of debris flow movement along a channel with four barriers. Panel a shows granular debris front reaching the first barrier. Panel b shows frontal impact deforming the first barrier and muddy water discharge reaching the second barrier. Panel c shows debris running up and rolling back at the first barrier with partial discharge passing through. Panel d shows peak runup overtopping the first barrier and muddy water discharge reaching the third barrier. Panel e shows debris overflow from the first barrier and surge reaching the second barrier. Panel f shows peak landing distance of 3.8 meter with partial discharge at the second and third barriers and muddy water reaching the fourth barrier. Panel g shows end of overflow at the first barrier with discharge of muddy water and fines through the barrier mesh. Panel h shows granular debris deposited behind all four barriers at the end of impact.Observed kinematics of debris flow interaction with four flexible barriers in the 190 m long flume captured by a UAV