An Examination of Surface Displacement at the Portuguese Bend Landslide, Southern California, Using Radar Interferometry

x, 65 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.SAR data constrain deformation of the Portuguese Bend landslide in space and time, and its movement is found to correlate with seasonal rainfall. Traditional InSAR methods estimate an average downslope displacement rate of 1.01 à ± 0.44 m/yr during the summer months. Interferograms show a consistent loss in phase coherence over the landslide for epochs greater than six months, especially in the winter. Interferograms become incoherent as a result of large displacement, and incoherence is used to map the spatial extent of the slide through time. The displacement rate increases several weeks after the beginning of the rainy season as rainwater percolating into the slide elevates pore pressure. SAR data processed using the permanent scatterer technique are partially successful on the rapidly moving landslide. Scatterers are identified on the landslide, but rates are underpredicted due to unwrapping uncertainty. A model based on rainfall-initiated landslides constrains diffusivity using InSAR observations.Committee in Charge: Dr. Joshua R. Roering, Chair; Dr. David A. Schmidt; Dr. Alan W. Rempe