Complex hydraulic interactions between compartmentalized carbonate aquifers and heterogeneous siliciclastic successions: a case study in southern Italy

Abstract

Abstract:The sedimentary sequences containing lithologic units with low permeability represent hydrogeologic systems which, as of now, have been little studied despite their diffusion worldwide. A hydrogeologic study, aimed to assess the main factors controlling the groundwater flow dynamics in such systems and their hydraulic interactions with nearby carbonate aquifers, has been carried out in Longano (Isernia, Southern Italy).The analysis of the hydraulic heads, combined with the regimes of the springs and the electric conductivity of the groundwater, mainly reflect vertical and lateral heterogeneities of the media in terms of hydraulic properties. In particular, the flow system is controlled by lateral heterogeneities, which characterize a surficial horizon made up of clayey colluviums and talus deposits, separated from the deeper saturated, fissured bedrock. One-to-ten relationships in hydraulic heads, monitored in piezometers crossing the fissured media, further uphold the crucial role played by the lateral contrasts of permeability in controlling the flow dynamics. On the whole, significant interactions with the nearby carbonate hydrostructure take place. Nevertheless, the heterogeneities of the siliciclastic succession and surficial horizon, coupled with the compartmentalization of the carbonate system, leads to a complex hydrogeological scenario.In a wider perspective, this study gives information of utmost importance in order to improve the implementation of mathematical models and configuration of tapping works within these heterogeneous and complex settings.

Integrating Hydrogeological and Microbiological Data and Modelling to Characterize the Hydraulic Features and Behaviour of Coastal Carbonate Aquifers: A Case in Western Cuba

“…On the contrary, taking into account the increase of the hydraulic gradient from 0.02% (far from the fault zones) to 1.9-4.2% (close to the fault zones) along the south-western edge of the test site, it seems that a lower-permeability fault core is associated to the local fault zones, which partially impedes fluid flow, causing the gradient to locally rise. This relationship between hydraulic gradient increase and lower-permeability fault core is in agreement with the results of experimental studies carried out in other carbonate aquifers, fissured and karstified, where the groundwater flow lines are approximately orthogonal to the direction of the fault core [36][37][38][39][40][41][42][43].…”

Hydrodynamics in Evaporate-Bearing Fine-Grained Successions Investigated through an Interdisciplinary Approach: A Test Study in Southern Italy—Hydrogeological Behaviour of Heterogeneous Low-Permeability Media

“…The isotopic composition of spring and groundwater samples did not significantly vary over time (Table 2; variations were lower than the 2 error of the 18 O and 2 H analyses), with the exception of VPS. Moreover, temporal variations were attenuated to less than 5% of that observed in the precipitation ( Figure 6), according to the observations made in other aquifer types (e.g., [46][47][48][49]).…”

Recharge processes of Matese karst massif (southern Italy)

“…Torano and Maretto springs could be supplied from the same aquifer, but from different conduits net. The role of faulting in the groundwater flow has been described by Aquino et al (2015) in a north-western sector of Matese massif.…”