A First Simulation of the Impact upon the Hidroagoyán Dam Due to Lahars Triggered by an 1877-Type Cotopaxi Eruption in Ecuador

We forecast the impact that the lahars triggered on the summit of the Cotopaxi volcano in Ecuador would have upon the Hidroagoyán Dam should an 1877-type catastrophic eruption occur nowadays, with disastrous implications for the energy production of Ecuador. The Cotopaxi’ lahars have been simulated with the use of different computational models, yet none of them were so extended as to map their entire path to the dam. To fill this gap, we applied a version of the semi-empirical Cellular Automata LLUNPIY model to simulate primary and secondary lahars flowing from the summit of the Cotopaxi volcano until they reach the Hidroagoyán Dam in Baños. This version of LLUNPIY accounts for the triggering event by pyroclastic bombs and has already been validated by its successful simulation of the northbound 1877 cataclysmic lahars of the Cotopaxi volcano. The likely consequences of a similar disaster are discussed considering present territorial conditions. Computer simulations of natural hazards of this type represent a powerful tool that can be used when planning for the mitigation of environmental and social risks.