Climatic effect of ENSO associated with landslide occurrence in the Central Andes, Mendoza province, Argentina.

MOREIRAS, S.M.

LANDSLIDES

International Consortium on Landslides

Año: 2005 vol. 2 p. 53 - 59

Temporal distribution of landslides can be verified by means of climatic anomalies linked to the ENSO phenomenon. An increasing number of landslides triggered by rainfall has been recorded during warm episodes (El Niño) in the Cordillera Frontal, and a decreasing number during cold episodes (La Niña), concluding that this geological province is mainly influenced by the Pacific Anticyclone. However, slope instability in the Precordillera, located east of the Cordillera Frontal, seems to be mainly influenced by the Atlantic Anticyclone. Analysis of variance shows that there is no significant difference between landslide records and cold-warm episodes, and a higher number of landslides were recorded in years linked to wet periods than during dry periods. Furthermore, precipitation threshold value associated with landslide occurrence and antecedent precipitation are analysed.