In recent years, the evaluation of water resources is acquiring ever greater importance
mainly due to the world population growth, especially in areas like the Mediterranean region
where rainfall has shown a generally negative trend, also characterized by shorter and even
more intense events. Furthermore, the ever-increasing demand for high-quality drinking water
highlights the importance of correct monitoring and careful management of the resource.
The area of the Sibillini Mountains National Park, located in the central Apennines (central
Italy), proves to be particularly suitable for a quantitative study of the water resource due
to the excellent water quality widely exploited for drinkable uses.
This sector of the Apennine ridge is characterized by suspended aquifers, even of large
dimensions, and by a deep basal aquifer hosted within fractured and karsti?ed micritic limestones.
The monitoring, in some cases for decades, of the discharges emerging from some important
spring systems and of some river reaches that drain the waters circulating within the basal
aquifer has highlighted a constant and progressive decrease in stored water resources. This
phenomenon, as mentioned, is certainly linked to the rainfall trend recorded in recent decades
which, especially concerning the time of residence of the snowfalls on the ground, has shown
a marked decrease. However, the role played by the strong increase in forest cover along
the recharge areas within the carbonate ridge over the last 50-60 years is underestimated.
The lower in?ltration linked to the consumption of trees, especially in the summer season,
combined with the amount of precipitation lost through interception or evapotranspiration
phenomena, has been shown to reach values in places higher than 25-30%.