Mass Wasting in Chile
Hazards
Chile's middle and southern regions are areas of high susceptibility to mass wasting, while the northern regions are classified with low to very low susceptibility, as you can see on this map from ThinkHazard.
The reason for the concentration of landslide hazards in the central and southern regions is explained by Sergio Sepulveda, a student at the University of Chile. Sepulveda says,
"In Chile, debris flows are usually triggered by heavy rainfall, although the amounts of precipitation required to initiate the flows are very variable according to the climatic regime".
Northern areas of Chile are classified as having an extremely dry climate (< 2 in of rain/yr), as it boasts the driest desert in the world, the Atacama. The central regions of Chile are classified as having a Mediterranean-like climate (12-40 in/yr), and the southern regions rainy-temperate (40-80 in/yr, sometimes reaching up to 157 inches in the southern coastal islands). Of course, earthquakes are also included in the picture, as heavy movement disturbs sediment in the mountains, causing it to tumble down as seen in a study by the American Geophysical Union of Chile's Horcon formation.
Warning Systems / Precautions
Yet again, I wasn't able to find information on whether Chile has a warning system or preventative measures for these types of hazards, but from looking at several news reports it seems that the president usually declares a state of emergency after the fact, and people are evacuated aerially as needed.
I also discovered an Emergency Plan of Action issued on April 10th, 2015 after a massive flood the previous month caused landslides all around the Antofagasta, Atacama and Coquimbo regions. According to this "PoA", the emergency responses to the different areas encompassed 7 main issues regarding both physical and human resources: livelihood, food security, shelter, restoration of family links, emergency health, psychosocial support, and water and sanitation. I'm not sure if the same measures are taken for every landslide hazard in Chile, but I think it gives an idea :-)
Citations
I loved that risk map. So easy to visually see where are the most problematic areas. I am curious what you'll find next week when we talk about soil issues...both very connected.
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