Influence of Climate Change and Human Activity on Fontanili (Lowland Springs) and Shallow Aquifers in the Southern Turin Po Plain (Italy)

Fontanili are peculiar lowland springs that occur in Northern Italy along the transition zone between the higher and lower Po plain (called the ‘‘fontanili line’’), where the phreatic table of alluvial shallow aquifer spontaneously or anthropically reaches the soil surface. These springs provide a variety of ecological benefits such as self-cleansing of water, stable water temperature and unique ecosystems. They are extremely important from an ecological and hydrogeological point of view, as well key indicators for the effects of climate change and anthropic influence on the shallow aquifer which directly supplies their discharge. Unfortunately, fontanili appear to be deteriorating or completely disappearing over time, so it’s important to determine the danger they are facing in order to enable authorities to monitor and manage them properly and observe relevant data that is certainly connected to climate change. Consequently, an assessment of the hydrogeological features of these springs and the shallow aquifer is also important.

This study is focused on a sector of the southern Turin Po Plain, in Piedmont (Italy) with data being collected during the year 2022, a record-breaking year for drought and heat in the area. Fontanili were mapped during the summer and autumn of 2022, revealing a total of 92 springs, most of which were revealed to be inactive and lacking water, with only 26 being active and only in autumn. The spring heads were grouped into 21 systems based on the primary canal that collected their waters. To analyse the features of the shallow aquifer, piezometric and hydrochemical studies were also conducted.

Piezometric level of the shallow aquifer appeared to have decreased in time and didn’t reach the surface. This situation created the conditions for the fontanili’s disappearance. From a hydrochemical point of view, groundwater samples belong to the calcium bicarbonate facies, while surface water samples belong to the calcium sulphide facies. Fontanili samples mostly appeared to have the same characteristics of well samples, confirming the springs are supplied by the shallow aquifer. Hydrochemical data appeared to be consistent with the previous literature with only four samples showing concentrations of nitrate or nitrite unsuitable for human consumption: this is connected to land use and agricultural practices, as these concentrations are higher in wells in the northern sector of the area, where activities are more intense. However, all the samples have excellent quality for agricultural when compared to the Sodium Adsorption Ratio Wilcox diagram.

The study shows that fontanili in the southern Turin Plain faced a critical situation in 2022 due to the decrease in piezometric level caused by climate change, alongside lack of maintenance and agricultural practices that contributed both to the overexploitation of the shallow aquifer and to the pollution of the water.

This study also aims to highlight how important preserving these precious resources is and how observing their evolution in time can help to mark the impact of climate phenomena that are being observed on a global scale.