No limits, no boundaries: a view of karst as the typical transboundary environment

The main features of karst make this natural environment an exemplar of the meaning of the word "trans-boundary", i.e. crossing political or administrative borders, at the national as well the international level. As a matter of fact, in karst territories it is very difficult to establish and define the limits of a water catchment, and to understand at what amount the more likely surface limits correspond to those that are present underground. A typical element of karst hydrogeology is the lack of correspondence between surface and subsurface limits, which implies significant doubts in the definition of each watershed, the amount of water that it may contain or receive, and so on. All of this is not merely a scientific question, to be treated in conferences for “technicians and scientists” only. Actually, a large amount of drinkable water is taken worldwide from karst aquifers, with very high quality of this precious natural resource. And, in the future, the percentage of drinkable water from karst aquifers is estimated to strongly increase. This means that there is an urgent need to better understand the karst environment, to protect and safeguard it and the natural resources therein, and to face these issues at the international level, without being limited by administrative borders. Boundaries do not exist in karst. Water flows from one state to the other, and infiltrates underground, moving from a country to another, whilst pollution actions carried out in a site can be transferred with all their negative impacts to a nearby town, district, or country. When dealing with karst, we have to on one hand, face the high complexity of its hydrology and hydrogeology; and, on the other, we are forced to work together, because studies confined to only one patch of territory will not be representative of the whole picture. Karst teaches us another crucial lesson: we need to cooperate with people living in karst, to transfer and disseminate properly the results of our studies (starting from younger generations), to let them be aware of the fragility of karst, and its importance for them, for their life, their future. To jointly build resilience, that is the ability to cope with natural hazards and the changes they cause, and to help the human system adapt itself to the negative consequences of a disaster.