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Hydrogeological risk: definition and situation in Italy

Hydrogeological risk: definition and situation in Italy

Hydrogeological risk: together with the seismic and volcanic ones, it is to be considered one of the major environmental risks connected to human activities. From the name, which recalls water, it could be less scary, and instead we have every reason to be on guard against this category. We will see it from the updated numbers, thanks to reports from Legambiente, and returning in mind to numerous episodes we have witnessed, in Italy and in the world.

Hydrogeological risk: definition

The hydrogeological risk in practice translates into an increase in landslides and landslides caused by soil erosion or flooding, events that we usually expect when they occur abnormal or extreme weather conditions. A flood, for example. Endless rains, perhaps after a long period without a drop falling from the sky.

More technically, almost mathematically speaking, the hydrogeological risk it is defined as the product between the probability that a hydrogeological event such as a flood or landslide will occur, therefore defined as “adverse”, and the potential environmental damage to the population and infrastructures that can derive from this event.

There are so many examples of hydrogeological risk, Unfortunately. For example, it may be the risk deriving from unstable slopes for geological and geomorphological reasons. Or it can be rivers and waterways in general that give rise to hydrogeological risk when they "react badly" to excessive rainfall.

In recent years we have been spoiled for choice for both cases I mentioned, just think locally and rivers that overflow and stretches of mountains that collapse have "made headlines" in the newspapers with lots of damage to us, to our homes, to all the productive activities that had been established in a territory at hydrogeological risk. Aware or not, when it happens, the catastrophe happens, and it is usually democratic, or at least causal, in choosing its victims.

The fact is that if we continue to create the conditions to increase the hydrogeological risk on our territory, population - that is us - services and activities will be increasingly threatened by events that may be unpredictable, calendar in hand, but certainly avoidable. Maybe not with certainty, avoidable, but we can commit ourselves so that they are less and less probable. We could, we could, because for now, it seems that our country loves to play "with fire" in this sense. Put this way, it seems a contradiction, given that di hydrogeological risk it is, but the following data prove me right.

Hydrogeological risk in Italy

Italy in 2015 paid dearly for its continuous exposure to hydrogeological risk, we can in fact see the disastrous effects in the indisputable numbers that Legambiente reports in his report "Ecosystem at risk " recently presented. There is to tremble, even if it is not about seismic risk. To events that have fallen upon us from the sky, such as heavy rains and adverse weather, other causes have been added on which we have great room for maneuver.

The almost absence of actions by public administrations, as explained by Legambiente, but also the lack of funds dedicated to counteracting the hydrogeological risk, a problem that Italy sometimes seems not to want to see. In fact, far-sighted policies, in this sense ... not received. Extremely confined virtuous exceptions removed that do not catch the eye in large numbers.

In 2015 disastrous events related to hydrogeological risk they've caused 18 dead, 1 missing and 25 wounded, but not only. He is alive and well, but 3,694 people have been evacuated or left homeless and with everything "swept away" by landslides or floods. From North to South, to pay the consequences of our imprudent exposure to hydrogeological risk were 56 provinces, 115 municipalities and 133 localities.

2015 is over, the accounts are closed, but today, every day, while we are reading these lines, scrolling through numbers that often do not have the power to communicate the drama of the situation, there are no less than 7 million people on Italian soil. in danger because of the hydrogeological risk that hovers. Landslides or floods lurking and, tanned as our territory is in many areas, it is a moment to find ourselves counting lost lives and irreparable damage.

What can we expect in 2016? It is legitimate to ask ourselves, as we have almost reached the middle of the year, and it is fair to hope that the sad 2015 could have taught us something. Those who hope, agree, and even the data at the moment support this optimistic view. In fact, 80% of the municipalities interviewed by Legambiente appears to have drawn up urban plans that have incorporated the perimeter of the areas exposed to greater danger. This does not mean that there are still areas where the wild building increases the hydrogeological risk to which we are subjected, us.

Areas with hydrogeological risk

In Italy there are not few and not little known areas with high hydrogeological risk. Campania, Calabria, Piedmont, Sicily, Liguria are those that are most affected by phenomena linked to this risk. For various reasons, there is no rule, unfortunately, but a series of contributing causes, connected together in a complicated way, but it is worthwhile and it is necessary to try to investigate at least in part the mechanisms that they transform hydrogeological risk, a probability, into bad certainties.

Sometimes the nature of the territory is at the base, therefore the hydrogeological risk it is strictly dependent on the geology and geomorphology of the soils and slopes. I am thinking of Liguria, but it is by no means a unique case. In many other areas, however, there is man's hand.

And how if there is and, more than a hand, there are the crane and the brick placed by man who, with all his commitment, consciously feeling immune from hydrogeological risk, he built roads, bridges, railways, houses, changing the territory. What's wrong with that? In some cases, our intervention has made the hydrogeological risk making dangerous areas that have always shown no problems whatsoever even with floods in progress.

It is not just the misplaced or poorly integrated infrastructure that makes us responsible for many of the victims ofhydrogeological risk, we are also involved for the deforestation and every time we change the intended use of a land without planning well or evaluating correlation with adverse meteorological phenomena.

We can also blame the "crazy" climate, and say that they are there anomalous phenomena, waving newspaper headlines that talk about the rainiest month ever, the hottest summer in the last few years, and so on. The fact is that, in reality, we are among the worst enemies of ourselves, regarding the hydrogeological risk.

Hydrogeological risk: map

Well understood that more can and should be done for limit hydrogeological risk in Italy, but that there are elements that make it high and that we cannot control, here is a useful map. Beyond human and non-human responsibilities, what is at the origin of the victims and the damage is the mix of all the factors.

Factors that produce an improvable situation. Those who are not satisfied with observing the map and want to learn more can safely navigate in the CNR site dedicated to hydrogeological risk in Italy.

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