Álvaro Montaña
Geographer from Geute Conservación Sur
How likely is the rise in a ravine, that is, the bed of a dried river, is activated every few years and causes, in a few hours, human casualties, household destruction and road collapse in the world’s driest desert?
Considering this question, we surely remember terrible images like the Antofagasta flood in June 1991, March 2015 in Copiapó, August 2015 in Tocopilla, and recent floods in summer 2019 in Arica and Parinacota, Tarapacá and Antofagasta regions.
Is it a plan of nature or a curse of the territory we live in to coexist with these risky natural disasters which could be lethal? The answer from geography is no.
When we talk about natural risk, we refer to the ‘probability’ an event caused by physical-natural agents causes damages on infrastructures and people.
So, for the probability of a flood to cause damage, it logically and evidently depends on the existance of infrastructure and people living in areas exposed to these events. Therefore, if we avoid building at critical zones like borders (or dried beds) of rivers and ravines, we might avoid these tragedies.
We know it rains in the Chilean desert: on “El Niño” years and/or during summer rains in the Altiplano, when this occurs, it activates torrential beds that looked ‘dormant’ for long times which, paradogically, in that time of apparent calm (which might be years or decades), they were occupied by road, communications and household infrastructure.
Why more research, with so much trial and error; it’s time for action: banning human occupation of ravine and river beds, which might look so dried, but they’ll activate quickly. For these ‘exreme and unusual’ natural events not to cause damage on infrastructure and human lives, it depends on our decisions.
Natural risk can be avoided and/or minimised through territory planning that reduces the natural risk of floods and guides the occupation of river borders, a legislation that protects ecological, scenic, environmental and cultural values of river ecosystems, and doing research for accurate delimitation of the highest floodable beds of rivers and ravines.
We must build a new relationship with our rivers, considering especially natural risks coming from inappropriate human occupation of their borders: floods, waterlogging, among others. For floods not to be risky, it fortunately depends on our smart and aware territorial decisions.