Analysis of landslide explicative factors and susceptibility mapping in an andean context: The case of Azuay province (Ecuador)

Landslides present significant challenges in spatiotemporal prediction and can lead to devastating consequences. Understanding slope failure mechanisms is complicated by the difficulty in directly measuring physical parameters during these events. However, active remote sensing, particularly interferometric synthetic aperture radar (InSAR), has become a crucial tool for detecting and characterizing slow-moving landslides over large areas. This research focuses on measuring the deformation associated with the catastrophic landslide that occurred in Alausí on March 26, 2023. Persistent scatterer interferometry (PSI), utilizing the StaMPS algorithm, was applied to analyze deformation using ascending and descending Sentinel-1 time series data from 2021 to 2023. The study identifies two critical areas: Area A, corresponding to the leading scarp of the fatal landslide, and Area B, located approximately 1.3 km to the left of Area A, both of which belong to the same ancient scarp. The observed displacements in these areas exhibited average rates in the line-of-sight (LOS) direction for both ascending and descending orbits, as well as in the vertical and horizontal directions, ranging from one to two dozen millimeters per year. This data is invaluable for enhancing early warning systems and supporting post-disaster recovery efforts in the Andean region. Furthermore, the mapping of vertical and horizontal displacements allows for more accurate delineation of landslide boundaries and improved volume calculations, contributing to a clearer understanding of landslide dynamics. These insights are essential for developing more resilient communities and mitigating the risks posed by natural hazards.

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A Case Study of a Macro-Landslide in the High Mountain Areas of the Ecuadorian Andes: “La Cría” at the Azuay Province (Ecuador)

Torrijo,

Álvarez,

Garzón-Roca

2024

Land

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Large landslides, known as macro-landslides, pose a significant threat to the safety and stability of communities living in mountainous areas. In this work, an evaluation of a macro-landslide that occurred in the La Cría community (Azuay province, Ecuador) is conducted. This macro-landslide covered an extensive area of approximately 443 hectares and affected a population that is mainly dedicated to agriculture. Historically, a landslide was already identified in the area in the 1973 geological map. However, there has recently been a significant increase in the speed of the landslide, causing damage to infrastructure and homes, and directly affecting 97 homes of various structural typologies. The study area is characterised by its geological instability, influenced by the presence of reservoirs for agriculture. In addition, the community of La Cría within the landslide has experienced considerable population growth. The study conducted combines the use of a landslide susceptibility map with a multicriteria analysis (which considers the interactions of geological, hydrological and land use) and a stability evaluation based on limit equilibrium methods. The results show that most of the territory assessed, approximately 55%, presents with a very high susceptibility to landslides, and reveal that the geology and the interactions between local geology and water resource management are needed to prevent and mitigate the risks associated with mass movements in the area.

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Analysis of landslide explicative factors and susceptibility mapping in an andean context: The case of Azuay province (Ecuador)

Cited by 5 publications

References 144 publications

Considering the effect of non-landslide sample selection on landslide susceptibility assessment

Considering the effect of non-landslide sample selection on landslide susceptibility assessment

Multitemporal characterization of landslide displacement patterns in the Andean region using InSAR

A Case Study of a Macro-Landslide in the High Mountain Areas of the Ecuadorian Andes: “La Cría” at the Azuay Province (Ecuador)

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