Monitoring landslide activity is of paramount importance for
landslide studies. In the landslide studies, remote sensing
imagery is a very powerful tool for landslide monitoring
because it offers a synoptic view of the landslide that can be
repeated at different time intervals. Landslide monitoring is to
light the way for new landslide and retrogressive failure in the
old landslide. Landslide monitoring is generally accomplished
by field-based geodetic, geotechnical and geophysical
techniques complemented with aerial photo interpretation
(Mikkelsen, 1996; Keaton and DeGraff, 1996). Most field
techniques, however, only provide point-based measurements of
the landslides. In addition, they do not give information on past
movement episodes. Although ground-based techniques are