Testing indirect methods to infer hydraulic conductivity in streambed sediments: preliminary results

Hydraulic conductivity, grain-size parameters, empirical approach, Kozeny-Carman model

Modellistica geologica e idrogeologica tridimensionale per la valutazione quali-quantitativa delle risorse idriche sotterranee

Management of groundwater systems requires efficient modeling tools to evaluate the available resources and to define the water balance. The value of these instruments depends on the accuracy of geological and hydrogeological conceptual model. As part of a research project aimed at assessing Groundwater Resources in strategic aquifers of Sardinia, it was tested a methodology for quantitative and qualitative study of groundwater resources, based on the use of three-dimensional geological and hydrogeological modeling. The aim of this research is to provide a tool to support the decision-making process in water resources management and assessment, applicable in different hydrogeological settings. . The pilot study area is the porous Quaternary alluvial aquifer of the Cixerri Valley. The valley, located in the South-Western Sardinia, is an East-West oriented syncline linked to the tertiary tectonics, bordered by Paleozoic metamorphic and sedimentary formations and filled by tertiary and quaternary alluvial. The methodology can be summarized in three main phases. The first involved the construction of a Geodatabase (DB), where geological and hydrogeological data (geological maps and cross sections, geophysical data, wells and borehole logs, piezometric levels, hydrogeological parameters and geochemical features) were cataloged During the second phase a 3D geological model of the shallow Cixerri aquifer has been built. The data collected in the DB were validated and used for the construction of geological sections orthogonal and parallel to the fold axis. The interpolation of alluvial horizons of each sections help us to create the bottom surface of the alluvial aquifer. The third phase, currently being implemented, involves the construction of a hydrogeological 3D model and the estimation of the volume of the aquifer

Hydrogeological and hydrogeochemical modelling in the freatic aquifer of the Cixerri plain (Sardinia, Italy)

A hydrogeological modelling, supported by geological and hydrogeochemical data was performed. The proposed methodology was applied to the strategic aquifer of the Cixerri area (SW Sardinia, Italy). 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. In particular, this study aims to evaluate the potential risk of nitrate pollution in aquifers from agricultural practices by combining intrinsic aquifer vulnerability to contaminatio

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