Dpto. de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria
Dpto. de Ingeniería Geográfica y Técnicas de Expresión Gráfica, Universidad de Cantabria
Abstract. The Deba area is intensely affected by frequent shallow landslides triggered by rainfall. Relationships between rainfall and landslides in northern Spain, particularly for rainfall events driving multiple movements simultaneously, have not been explored in depth so far. This contribution explores the role of rainfall in landslide activity during a quite long time span, (60 years), from a large network of rainfall gauges and a complete inventory of landslides, and utilizing three different strategies of analysis. 1,180 landslides have been inventoried, and 3,241 rainfall episodes automatically recognized and characterized in terms of rainfall amount, duration and intensity. Antecedent rainfall has also been considered. Six episodes of intense rainfall, which have produced multiple landslides (> 50 % of the recent past occurrences) have been identified. The analysis provides different results: the extraordinary character of the triggering rainfall has been assessed, the meteorological conditions associated to those extreme episodes have been recognized and empirical rainfall threshold producing multiple landslides has been found (I = 7.7D-0.428) and compared with others described in literature. Results show that multiple landslide occurrences are triggered by extreme convective rainfall, intense, short and with limited horizontal extent, as well as a marked summer-autumn seasonality, characteristic of Mediterranean climate.
How to cite. Rivas, V., Remondo, J., Bonachea, J., and Sánchez-Espeso, J.: Rainfall and weather conditions inducing intense landslide activity in northern Spain (Deba, Guipúzcoa), Nat. Hazards Earth Syst. Sci. Discuss. [preprint], https://doi.org/10.5194/nhess-2019-416, 2020.
Received: 17 Dec 2019 – Discussion started: 21 Feb 2020
This work is focused on the analysis of relationships between landslides and precipitations covering the last 60 years. Landslide inventory has been elaborated and a rainfall database has been obtained from 15 rain gauges. In this period, 6 major landsliding events have been identified and a characterization of them has been carried out. An I-D threshold has been calculated and compared. The characterization of weather patterns, and the definition of their seasonality, is a relevant contribution
This work is focused on the analysis of relationships between landslides and precipitations...