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The research analyses the historical evolution of the water supply systems of the city of Benevento (southern Italy) during centuries. We focused on three main historical periods, namely the Roman, Lombard and Papal times, and the recent-present times. During this long historical time, the water supply amount and quality have changed many times, and this has probably affected the well-being and growth of the city. The best water quality characterized the Roman times, when large karst springs were tapped, feeding the town for centuries. In this period, the town experienced the largest population expansion. On the other hand, the most depressed period was the Papal times, coinciding with the isolation of the city, as it was an enclave of the Pontifical State. During this period, the water supply from external sources was not guaranteed and therefore it primarily derived from the local, low-quality water resources. Only after the unification of Italy, and also after the Second World War, the water supply systems have been improved, and new aqueducts have brought again high-quality waters to Benevento coming from karst aquifers. Nowadays, the drinking water management of Benevento is still a matter of debate. In the near future, the water from a dam-reservoir (Campolattaro dam, Tammaro River) will be exploited to guarantee the water needs of the city, and water-supply systems will undergo further changes. The knowledge about the historical evolution of the water supply of Benevento represents an essential requirement for consciously analyzing the future planning and management of water resources. [ABSTRACT FROM AUTHOR]

Analytical solutions for turbulent and laminar water flow conditions are developed considering the drainage process of a simple tank reservoir, using the Darcy–Weisbach and the Poiseuille laws, respectively. Near the critical value of the Reynolds number, the Darcy–Weisbach and the Poiseuille laws do not match, and there is a gap regarding the possibility of describing the drainage analytically. This gap corresponds to the critical zone of the Moody diagram, where theoretically a constant discharge occurs under a decreasing hydraulic gradient. In the critical zone, this hydraulic behavior of the flow reflects the different energy losses occurring during the drainage, as the laminar flow is a more efficient flow condition than the turbulent one. In natural systems (e.g., springs and karst aquifers), a smooth transition from the turbulent to the laminar water flow occurs due to the heterogeneity in the medium. [ABSTRACT FROM AUTHOR]

Previous studies have shown that carbonate massifs of the Apennine chain (Italy) undergo deformation in response to groundwater level variations occurring in the saturated zone of karst aquifers. This study focuses on the Matese massif, hosting one of the main karst aquifers of the central-southern Apennine. Our analyses revealed a hydrological component in the time series of the horizontal and vertical ground displacements measured by GNSS (Global Navigation Satellite Systems) and InSAR (Interferometric Synthetic Aperture Radar). In particular, contraction and dilatation phases of the karst massif appear associated with the lowering and rising of the groundwater levels, respectively. Various authors have explained this phenomenon by the widening and closing of sub-vertical waterfilled fractures dissecting the rock mass due to varying hydraulic heads, neglecting the role of the effective stress state acting in the aquifer saturated zone. We present new equations explaining the observed deformational phenomenon in its generality, which are based on Terzaghi’s effective stress principle (Skempton’s generalization) and linear elasticity. The study shows that hydrological deformation of karst massifs is similar to the thermal expansion of solids. In the first case, the deformation is primarily due to pore water pressure variations occurring in the aquifer saturated zone, which are associated with water table oscillations, and is controlled by the elastic properties of the rock mass and the coefficient of earth pressure at rest, K0. [ABSTRACT FROM AUTHOR]

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