LANDSLIDE AND GLACIAL LAKE OUTBURST FLOOD HAZARD IN THE CHUCCHÚN RIVER BASIN, CORDILLERA BLANCA, PERU
The Chucchún River basin was hit by glacial lake outburst flood (GLOF) triggered by ice/rock avalanche which caused spill over from the Lake 513 (April 11, 2010). The whole region is also highly susceptible for landslide occurrences, therefore the GLOF and landslide multi-hazard map were prepared for the watershed. Definition of the GLOF hazard zones was done using 1D mathematical model HEC-RAS for modeling of flooded areas. Landslide hazard zonation was based on landslide inventory mapping and historical records of the landslide occurrences. Resulting multi-hazard map shows that 26% of the studied river basin is under some degree of hazard from landslides or GLOFs. It clearly shows the most endangered inhabited areas as well as places, where floods and landslides may adversely affect each other increasing intensity of the hazardous event.