Developing a geotechnical database to improve slope stability assessments in Quito, Ecuador

Quito, Ecuador, is a city at risk of many hazards including earthquakes, volcanic eruptions and landslides, compounded by the widespread presence of problematic volcanic soils known as Cangahua. This paper presents the preliminary results of data analyses undertaken on a new geotechnical database for Quito, compiled from a variety of sources. It is envisaged that this database will be utilised primarily for improving our understanding of landslide hazard drivers in communities in and around the city. The preliminary statistical analyses include probability density functions and regression models for soil parameters. A difference in geotechnical variability between the north and the south of the city was observed. The study also presents data from unmanned aerial vehicle (UAV) mapping of an informally constructed hillside community in Quito, identifying house-scale slope features (e.g. cut slopes and house loading) that may affect local landslide hazard processes. Together, the statistical analyses of these datasets will provide the inputs for physics-based stochastic slope stability modelling. Recommendations for future data collection are given to support the development of a higher resolution Quito database and facilitate the improvement of community-scale slope stability assessments.