DInSAR and statistical modeling to assess landslides: The case study of Sierras Chicas (central Argentina)

Abstract

The main goal of this investigation was to assess landslides in the steep West-facing slope of the Sierras Chicas mountains in central Argentina using two complementary approaches: Differential SAR interferometry (DinSAR) and statistical modeling. The combination of the geological characteristics of the area, wildfires, intense rainfall events and human disturbances have made the area highly susceptible to landslides. This condition has been recently aggravated with the construction of a roadway. In this work, we applied DInSAR methods to explore the suitability of COSMO-SkyMed (CSK) acquisitions to measure displacements and we used Sentinel-1 C-band images for accuracy comparison. In addition, Generalized Linear Models were fitted to identify landslide-conditioning factors. Based on the results obtained, Sentinel-1 proved to be the most adequate source of images to perform interferometry, in contrast to Cosmo Skymed imagery that showed very poor coherence in the study area. The statistical modeling identified slope degree, distance to roads and fire frequency as the main variables explaining landslide occurrence on the west escarpment of the Sierras Chicas. Results will hopefully contribute to improving future applications of SAR interferometry both in the study area and others with similar characteristics, as well as the tools and knowledge for decision making in engineering and urban development projects in order to minimize risk.