Alberto Carletti

Nitrate occurrence in groundwater hosted in hard-rock aquifers: estimating background values at a regional scale

This study was aimed at assessing the occurrence of nitrate in poorly anthropized areas at a regional scale, as an attempt to estimate the nitrate background in areas far from intense agriculture, farming, industrial activities and urban areas. Nitrate concentrations, together with physical-chemical parameters and major anions and cations, were determined in 49 spring waters flowing out of granitic and metamorphic rocks in Sardinia (Italy). Nitrate in the spring waters was in the range of

Electrical Resistivity Tomography for the identification of the alluvium-Triassic boundary in Medenine Region (SE Tunisia)

The Jeffara Plain, in Medenine region (SE Tunisia), suffers of dry climatic conditions. Lower Triassic sandstones widely outcrop within the Plain and they host a strategic aquifer exploited for drinking and irrigation purposes. An insufficient natural recharge and an increasing water demand have led to an overexploitation of such aquifer. Water harvesting techniques and particularly Managed Aquifer Recharge (MAR) systems can be useful tools for restoring groundwater resources. To better design the MAR system and to characterize the local geological setting, an Electrical Resistivity Tomography survey was conducted in six selected sites in the Jeffara Plain, within the frame of EU WADIS-MAR project.

3D hydrogeological modelling supported by geochemical mapping as an innovative approach for management of aquifers applied to the Nurra district (Sardinia, Italy)

A hydrogeological 3D modelling, supported by hydrogeochemical mapping and integrated interpretation of available data, was performed. The proposed methodology was applied to the strategic aquifer of the Nurra district (NW Sardinia, Italy). The finding of this work highlighted that structural history of the Nurra district exerts a relevant control on the hydrogeology and hydrochemistry of groundwater. The local connection of Triassic and Jurassic aquifers was proposed. The knowledge-base system will provide a suitable and effective tool for understanding and monitoring pollutants transfer dynamics into groundwater to better manage water resources and mitigate desertification processes.

Geological modelling for hydrogeological purposes in Oum Zessar area (SE Tunisia)

Lucchi, Renata G. ... et. al.-- 87° Congresso della Societa Geologica Italiana e 90° Congresso della Societa Italiana di Mineralogia e Petrologia, The Future of the Italian Geosciences - The Italian Geosciences of the Future, 10-12 September 2014, Milan, Italy.-- 1 pageThe Montellina Spring (370 m a.s.l.) represents an example of groundwater resource in mountain region. It is a significant source of drinking water located in the right side of the Dora Baltea Valley (Northwestern Italy), SW of Quincinetto town. This spring shows a morphological location along a ridge, 400 m from the Renanchio Torrent in the lower sector of the slope. The spring was investigated using various methodologies as geological survey, supported by photo interpretation, structural reconstruction, NaCl and fluorescent tracer tests, discharge measurements. This multidisciplinary approach, necessary due to the complex geological setting, is required for the importance of the Montellina Spring. It is interesting in the hydrogeological context of Western Alps for its high discharge, relatively constant over time (average 150 l/s), and for its location outside a fluvial incision and suspended about 40 m above the Dora Baltea valley floor (Lasagna et al. 2013). According to the geological setting, the hydrogeological reconstruction of the area suggests that the large amount of groundwater in the basin is essentially favoured by a highly fractured bedrock, covered by wide and thick bodies of glacial and gravitational sediments. The emergence of the water along the slope, in the Montellina Spring, is essentially due to a change of permeability between the deep bedrock and the shallow bedrock and/or surficial sediments. The deep bedrock, showing closed fractures and/or fractures filled by glacial deposits, is slightly permeable. The shallow bedrock, strongly loosened as result of gravitational phenomena, and the local gravitational sediments are, on the contrary, highly permeable. The concentration of water at the spring is due to several reasons. a) The spring is immediately downward a detachment niche, dipping towards the spring, that essentially drains the water connected to the change of permeability in the bedrock. b) It is along an important fracture, that carries a part of the losses of the Renanchio Torrent. c) Finally, it is favored by the visible and buried morphology. Although it is located along a ridge, the spring occurs in a small depression between a moraine and a landslide body. It also can be favored by the likely concave trend of buried base of the landslide. At last, tracer tests of the Renanchio Torrent water with fluorescent tracer are performed, with a continuous monitoring in the Montellina Spring. The surveys permit to verify and quantify the spring and torrent hydrogeological relationship, suggesting that only a small fraction of stream losses feeds the spring.

Integrated approach to choosing suitable areas for the realization of productive wells in rural areas of sub-Saharan Africa

Abstract Comprehensive geological, hydrogeological and hydrogeochemical investigations were carried out in the south of Hodh El Chargui (southeast Mauritania). Obtaining a hydrogeological conceptual model is crucial for groundwater resources development and management. This is especially true in developing countries and in the rural areas of sub-Saharan Africa. The chosen areas are represented by lithologies referring to a long geological time frame, dating from the Upper Neoproterozoic to the Quaternary age. We developed a methodology in order to identify sites that were suitable for the realization of productive, protected and correct wells to supply safe water to the rural community. A multicriteria approach to studying hydrogeology was used in the project area. In order to identify some main areas in which to carry out pilot interventions, criteria relating to water accessibility and availability, and to hydrogeological and water quality, were considered. Moreover, during the project, it was possible to transfer know-how and hand over responsibilities to the local population and bodies. Citation Ghiglieri, G. & Carletti, A. (2010) Integrated approach to choosing suitable areas for the realization of productive wells in rural areas of sub-Saharan Africa. Hydrol. Sci. J. 55(8), 1357–1370.