The access road to the powerhouse's hydraulic system's facilities in Guarumales (Azuay, Ecuador) presents a medium-sized landslide. Geophysical tests were conducted in the initial research stage, combining electrical and seismic methods. A SEV and HVSR surveys campaign have been taken as a reference for the analysis of the landslide area. The distribution of these test points has been at three different levels along the landslide where the access road crosses it and trying to cover the area's most extensive possible length and width. In the area, we find the geology dominated by the presence of schists, altered to different degrees and presenting blocks of material with a lower degree of alteration within colluvium formed by a clayey matrix and coarse material of the exact nature. There is also evidence of surface and groundwater in the area. The results obtained through SEV tests have allowed for defining the separation zone of the mobilized or sliding materials compared to the fixed or immobile ones (potentially, the sliding surface was marked). Using the HVSR technique, the natural vibration frequencies of the ground associated with the sliding mass (separation of seismic impedances between a two-layer model: mobile and fixed) have been determined. Previous authors proposed an empirical relationship establishing the exponential relationship, already proposed by previous authors, between sediment thickness and natural frequencies. It has been possible to determine the depth of the position of the loosely compacted sediment zone (and probably moving or mobilized) compared to that of compact materials (immobile) and thereby define the potential rupture surface.

On the afternoon of January 31, 2022, the northwest and central part of the city of Quito (Ecuador) was hit by a mud-flow that originated in one of the ravines of the Pichincha volcanic complex. According to the official reports, there were 28 fatalities, one missing person, 52 injured, and 53 families affected. The mudflow was triggered by unusual and heavy rainfall in the upper part of the drainage. However, the analysis of the deposits allowed us to establish the existence of anthropogenic elements as crucial components of a local disaster that affected daily life in the city for more than a week. Based on the preliminary data, we were able to determine that the mud and water flowed through different streets of the city, reaching a maximum distance of 3.2 km from the overflow point (collector, construction works to dam the drainage under the city). The analysis of the multimedia material published on social networks and in the press also made it possible to detect the change in the behavior of the flow during its evolution, which went from a hyper-concentrated flow to muddy water. A similar event occurred in 1975, and although it was a larger event (52000 m3, seven times larger than in 2022), it caused two deaths and little damage in the same area. The main causes of the disaster included urban development that did not meet the needs of the area and a lack of awareness or ignorance about the management and intervention of drainage in Quito City.