Cascading Processes and Multiple Hazards and Risks in Chilean Rivers: Lessons Learnt and Remaining Challenges

Characterized by pronounced seismicity, intense volcanism, high relief energy, and cryosphere changes, the Chilean climate, geology, and topography determine the suite of landscape-forming processes and disturbances that under certain circumstances may lead to extreme impacts on society, environment, and infrastructures. Earthquakes, volcanic eruptions, and floods are processes that naturally collide in Chilean river basins, producing process concatenations or cascades and resulting in complex multi-hazards and risks. This calls for a perspective shift, aiming at a multi-hazard approach that goes beyond the simple overlay of multiple single hazards to an approach that also considers interactions between these hazards and risks. In this chapter, we discuss how individual processes or disturbances may interact acting together to form cascades, using case studies from Chile (e.g. rivers affected by volcanic eruptions), and how the resulting hazards and risks could be assessed by integrating all aspects of hazard interactions together with exposure and vulnerability.