Deformations of a Rapidly Moving Landslide from High-Resolution Optical Satellite Imagery

Abstract

Spaceborne remote sensing provides important field observations of landslide movements over spatial and temporal scales that cannot be simultaneously achieved with traditional field instrumentation. Analyses of multi temporal data from both radar and optical spaceborne systems have been successfully used in the past to identify and map landslides over large areas. This study uses optical image correlation to measure deformations of the Portuguese Bend Landslide, a landslide south of the city of Los Angeles that moves 1 to 7 m/yr. Optical image correlation is applied to 0.5-m resolution satellite images to generate the displacement field across the landslide over a 9-month time period. The displacement field from optical image correlation compares favorably with the displacement field assessed by GPS stations monitoring on the landslide; however the data from optical image correlation provides more detail regarding variations in displacement across the landslide.