Occurrence and flow of groundwater in crystalline rocks of Sardinia and Calabria (Italy): an overview of current knowledge

Abstract

Crystalline rocks constitute aquifers that are of interest for water supply in many countries. In Italy, the hydrogeological characteristics of crystalline rocks are not well known and the interest in these aquifers is generally scarce. Nevertheless, the large extent of these rocks in Sardinia and Calabria regions and the local scarcity of water resources justify this preliminary analysis. Crossing the information derived by the available data on climate conditions, type of crystalline rock, structural setting, characteristics of wells and springs, base flow of streams and rivers and pumping test results, a preliminary quantification of the potential yield of the crystalline aquifers of both regions was performed. The processing of data involving different aspects confirmed that the crystalline rocks of Sardinia and Calabria form low-permeability aquifers where groundwater circulation occurs in the weathered layer and, mainly, in the most fissured layers closest to the surface. In the heavily fractured zones, it was seen that the groundwater flow is more active and can also occur at a greater depth. Groundwater mainly outflows in the valleys, feeding streams, numerous low discharge springs and surrounding aquifers. Climate, rock covers and tectonic style influence the aquifer yield, which has been evaluated herein to range from 1 to 2 L/s per km2 and from 2 to 12 L/s per km2 in Sardinia and Calabria, respectively. This preliminary characterization shows that there are reasons to deepen the present knowledge on these aquifers in order to optimize the present use of their groundwater resources

Review: Hydrogeology of weathered crystalline/hard-rock aquifers—guidelines for the operational survey and management of their groundwater resources

“…1). Worthington et al (2016) confirm this conceptual model, which is today more and more accepted within the hydrogeological community and used by several authors to explain their observations (see for instance Allé et al 2017;Baiocchi et al 2014Baiocchi et al , 2016Guihéneuf et al 2017;Soro et al 2017;Vouillamoz et al 2014Vouillamoz et al , 2015Wubda et al 2017, etc. ).…”

“…The role of weathering in creation of the fractured layer is also directly or indirectly confirmed by the data sets of most of the authors working on HRA. See for instance Davies et al (2014) and the countries cited previously, as well as Chilton and Smith-Carington (1984), Chilton and Foster (1995), Howard (1999, 2000), Chirindja et al (2017), Dickson et al (2018), Muchingami et al (2019) and Vassolo et al (2019) for Africa; Chambel (2014) for Portugal; Comte et al (2012) for Ireland; Tan et al (2017) for Denmark; Riber et al (2017) for Sweden; Francés et al (2014) for Spain; Krasny (1996) for Central Europe; Baiocchi et al (2014Baiocchi et al ( , 2016 for the Mediterranean Europe; Chou et al (2014) and Chuang et al (2016) for Taiwan; David et al (2014) for Australia; Riber et al (2017), Jahns (1943, Hart (2016), Sanford (2017), Meyzonnat et al (2018) and Setlur et al (2019) for North America, etc. Even if several authors have not attributed the fractures to weathering processes, some others keep an ambiguity on this genetic relationship, while others do not challenge or discuss this issue at all, at least for the uppermost crust (0-2 km; Achtziger-Zupancic et al 2017;Ingebritsen and Gleeson 2017).…”

Artificial recharge of a shallow hard rock aquifer as a climate change mitigation method: model solution from the Czech Republic

“…A major part of Czech Republic is formed by crystalline bedrock, where groundwater occurs in shallow aquifer in permeable fissures and weathered zones. Similar hydrogeologic structures have been recognized as an interesting alternative groundwater resource by several researchers in different regions (Gustafson and Krásný 1994;Guihéneuf et al 2014;Baiocchi et al 2016). Shallow fissured aquifers may locally reach to depths of several tens of meters.…”

Quantificação do Potencial Hídrico Subterrâneo do Baixo Curso do Rio Piracicaba (MG): Interação das Águas Subterrâneas e Superficiais

“…Os deflúvios superficiais de regime de escoamento permanente recebem águas do escoamento de base ou o componente subterrâneo (Baiocchi et al, 2016). Nos sistemas aquíferos, os volumes de água de entrada são iguais aos de saída, estabelecendo um equilíbrio de fluxo das águas, de forma que, o volume restituído das águas subterrâneas aos rios, é passível de cálculo, obtendo-se o volume da participação das águas subterrâneas no escoamento superficial total (Babaye et al, 2019;Baiamonte et al, 2017;Hao et al, 2018).…”