The share of landslides in the occurrence of natural hazards and the significance of El Niño in the cordillera blanca and Cordillera Negra mountains, Peru

Abstract

Various types of natural hazards are often compared, in terms of danger or frequency of recurrence. Such analyses are, among other things, influenced by the character and quality of the database used. The Peruvian DesInventar database is homogenous and, thus, serves as a useful tool for describing the significance of landslides and evaluating the role of the El Niño Effect among different causes of catastrophes. During the 1971-2009 period, the most frequent type of natural hazard in the Ancash Department was alluvion (a local term for debris flow), followed by floods and extreme rainfall. If we group various forms of mass movement together, they comprise a dominant portion among natural hazards. A major portion of natural hazards are generated by the direct impacts of extreme hydrometeorological events. Considering the influence of El Niño episodes, it is important to emphasize the fact that 41% of all catastrophes caused by extreme weather, during the observed period, were generated by this phenomenon. This research was conducted within the framework of IPL Project M 129 (Evaluation of natural hazards associated with rapid glacial retreat in Cordillera Blanca, Peru) and the World Centre of Excellence on Landslide Risk Reduction, registered in the Czech Republic (Landslide field research and capacity building through international collaboration). Financial support was provided by the Ministry of Education, Youth and Sports of the Czech Republic, project no. MSM0021620831 "Geographic Systems and Risk Processes in the Context of Global Change and European Integration".