Change Detection and Feature Extraction of Debris-Flow Initiation by Rock-Slope Failure Using Point Cloud Processing
Table 2
Change detection results of debris flows.
No.
Year
Color scale (m)
Topographic changes
(a)
2005–2007
−1.0–1.0
An extensive positive change around 0.3 m to 0.9 m on the slope represents a mass deposition which is almost caused by the debris delivered by the debris flows. Obvious negative changes occurred along the big chutes of debris flows in lower Sabino Canyon, representing strong erosion caused by the scour of debris flows.
(b)
2007–2011
−4.5–4.5
A wide negative change represents continuous weathering and erosion, while a relatively small positive change existed at the lower canyon on its west side, signifying the continuous sediment deposition in that area.
(c)
2007–2011
−1.0–1.0
A more distinct weathering and erosion on the slopes and obvious sediment in the Sabino Creek.
(d)
2011–2015
−1.0–1.0
Positive change around 0.3 m to 0.9 exists on the slope showing a mass deposition caused by the debris delivered by the debris flows. Negative changes occurred along the big chutes of the debris flows in lower Sabino Canyon, representing the strong erosion caused by the scour of the debris flows.
