Newly-formed landslides and reactivated landslides can
be surveyed by contrasting the post-event satellite images with the
pre-event images. In this study, the time spans between pre-event
and post-event satellite images are less than two months. A newlyformed
landslide will not have appeared in the pre-event satellite
image, which means that the area was not affected by landsliding in
the two months before the typhoon events. In contrast, reactivated
landslide refers to an area that had been affected by a prior typhoon
event, which was again disturbed in the subsequent typhoon event