Rockslide Mapping in Norway by Means of Interferometric SAR Time Series Analysis

Abstract

Rockslides have a high socioeconomic and environmental importance in many coun- tries. Norway is particularly susceptible to large rockslides due to its many fjords and steep mountains. One of the most dangerous hazards related to rock slope failures are tsunamis that can lead to large loss of life. It is therefore very important to systemati- cally identify potential unstable rock slopes. In this thesis, we consider the use of satellite remote sensing interferometric syn- thetic aperture radar (InSAR) for detecting surface displacement in rural areas of Norway. The main focus of the work has been on developing small baseline (SB) InSAR time series methods for mapping and monitoring of rockslides in Norway. The first part of the thesis is a basic review of the satellite SAR imaging instrument, with a focus on the InSAR methodology. Different satellite sensors and their limitations is discussed. The introduction chapters have been written with the nonspecialist in mind. In the second part of the thesis, we present a discussion about particular InSAR processing challenges in Norway, as well as preliminary results from two ongoing research projects, with the aim of demonstrating the possibilities that emerges by using new high-resolution SAR sensors, as well as the potential to perform continuous surface displacement monitoring using radar corner reflectors. The last chapters of the thesis demonstrate that InSAR is a powerful tool that can be used to identify the relative magnitude and spatial pattern of active rockslide sites on both a regional and individual rockslide site scale.