Landscape evolution as a key driver of flood and landslide hazards: tectonic and hydrogeomorphological evidence from the central Paute River basin, Ecuador

Landscape evolution principles provide a conceptual framework for understanding how relief develops through long-term interaction of tectonics, climate, and surface processes. In tectonically active mountain regions, these interactions strongly influence the spatial distribution and recurrence of hydrogeomorphological hazards affecting human settlements (Winckell et al., 1997).

The objective of this research is to evaluate the role of landscape evolution as a control factor in flood and landslide hazards within the central Paute River basin, with particular attention to tectonic structures, hydrogeomorphological adjustments, hillslope dynamics, and their interactions with anthropogenic environments. The analysis combines multiple source and scale datasets, including a detailed mass-movement inventory derived from historical images and official cartography from the Geographical Institute of Ecuador (SIGTIERRAS, 2014) and the National Secretariat for Risk Management (SNGRE, 2024). These data were complemented with high-resolution unmanned aerial vehicle (UAV) surveys conducted annually in identified active sectors, which enable documentation of recent reactivations and relevant geomorphic changes.

Results show that floods and landslide hazards are strongly conditioned by long-term landscape evolution. The valley orientations controlled by structures and the inherited sedimentary environments condition the floodplain development and recurrent overbank flooding along the Burgay, Déleg, and Paute Rivers; particularly in the cities of Biblián, Azogues, Déleg, and Paute, provide a clear example of how un-equilibrated base-level conditions influence the hazard (Torres et al., 2022; Torres Ramírez, 2022). Landslide activity is mainly concentrated on slopes shaped by lithological contrasts, tectonic discontinuities, and the presence of previous landslides (Torres-Ramírez & Marco-Molina, 2025), as demonstrated by large-scale events such as La Josefina in 1993 (Plaza & Egüez, 1993), with rainfall acting as a trigger mechanism rather than a primary cause.

These findings reveal that floods and landslides in the central Paute River basin are direct expressions of an evolving landscape in which human settlements are located. Identifying geomorphic controls on hazardous processes provides a better understanding of risk patterns and supports more informed landscape approaches to land-use planning and hazard management in intermontane Andean regions.

Keywords: Landscape evolution, Hydrogeomorphology, Landslides, Floods, Paute river basin, Ecuador

References:

Plaza, G., & Egüez, A. (1993). Consideraciones Geológicas-Geotécnicas sobre el Deslizamiento de La Josefina. Coloquio científico El deslizamiento de La Josefina.

SIGTIERRAS. (2014). Mosaicos de ortofotos a nivel nacional. Sistema Nacional de Información de Tierras Rurales e Infraestructura Tecnológica. Quito, Ecuador. https://bit.ly/2twJiRn

SNGRE. (2024). Database Eventos Registrados. Secretaría Nacional de Gestión de Riesgos y Emergencias, Ecuador. Periodo 2010 a 2024.

Torres, R., Sánchez, E., & Marco, J. (2022). Análisis de la dinámica fluvial del río Burgay al norte de la ciudad de Azogues (Ecuador) y su influencia en el medio urbano mediante técnicas fotogramétricas y TWITTER API. XVII Coloquio Ibérico de Geografía, 332–343.

Torres Ramírez, R. (2022). Estimación morfométrica de la erosión lateral del río Burgay producida por las precipitaciones del 20 de abril de 2022. http://rua.ua.es/dspace/handle/10045/123388

Torres-Ramírez, R., & Marco-Molina, J. (2025). Inventario de movimientos en masa en la zona centro de la cuenca del Río Paute. Avances de La Geomorfología Española En 2023 - 2025.

Winckell, A., Zebrowski, C., & Sourdat, M. (1997). Las regiones y paisajes del Ecuador (Segunda Ed.). CEDIG.