1,720,993 research outputs found
Analisi dei processi di mescolamento attraverso indagini isotopiche in un acquifero carbonatico fratturato dell’Italia meridionale
No full textAnalysis of mixing processes in a fractured carbonate aquifer in Southern Italy through stable isotope investigation
No full textMixing of water in a carbonate aquifer, southern Italy, analysed through stable isotope investigations
Full text linkMixing of water was analysed in a carbonate aquifer, southern Italy, through stable isotope investigations (18O,δ2H). The input signal (rainwater) was compared with the isotopic content of a 35-meter groundwater vertical profile, over a 1-year period. Within the studied aquifer, recharge and flow are diffuse in a well-connected fissure network.
At the test site, the comparison between input and groundwater isotopic signals illustrates that no efficient mixing takes place in the whole unsaturated zone, between the fresh infiltration water and the stored water.
When analysing the stable isotopes composition of groundwater, significant variations were observed above the threshold elevation of 1062 m asl, while a nearly constant composition was observed below the same threshold. Thus, temporal variations in stable isotope composition of rainwater are completely attenuated just in the deeper phreatic zone.
On the whole, taking into consideration also the results of previous studies in the same area, the investigations showed that physical characteristics of the carbonate bedrock, as well as aquifer heterogeneity, are factors of utmost importance in influencing the complete mixing of water. These findings suggest a more complex scenario at catchment scale
Heterogeneous aquitard properties in sedimentary successions in the Apennine chain: case studies in southern Italy
No full textUnusual behaviour of epikarst in the Acqua dei Faggi carbonate aquifer (Southern Italy)
No full textHydrogeological and geophysical investigations demonstrated the existence of an epikarstic zone in a carbonate aquifer of Southern Italy, about 10 m thick. Nevertheless, the hydrogeological behaviour of the epikarst is different from that schematized by several authors. In the test site, the contrast in permeability at the bottom of the epikarst does not cause retention of percolation and storage of water in a perched temporary aquifer within the uppermost portion of the carbonate medium. Because of the high fracture density and good interconnection of openings within the underlying limestone, the percolation is diffuse also below the epikarstic zone, as well as the groundwater flow. The 'funnelling' effect into larger shafts does not play an important role on the hydrogeological behaviour of the aquifer
Updating of a DRASTIC-based Method for Specific Vulnerability Assessment in Carbonate Aquifers
No full textSome methodological modifications are suggested to improve a DRASTIC-based method as a reliable predictor of microbial contamination in extensively fractured and subordinately karstified carbonate aquifers. These modifications will allow a better assessment of vulnerability induced by the concentrated infiltration of surface runoff in two different scenarios: (a) when the karst system is entirely located within an unsaturated aquifer and (b) when the karst system is partially located within a saturated medium. The effectiveness of the updated method has been experimentally verified by comparing the vulnerability values with the results of a hydrogeological and microbiological study at a test site
Natural-gradient tracer experiments in epikarst: a test study in the Acqua dei Faggi experimental site, southern Italy
No full textA high-altitude temporary spring in a compartmentalized carbonate aquifer: the role of low-permeability faults and karst conduits
No full textThe effect of low-permeability fault zones on groundwater flow in a compartmentalized system. Experimental evidence from a carbonate aquifer (Southern Italy)
No full textIntegrative measures for protection of carbonate aquifers against microbial pollution in central–southern Italy
No full textThe refinement of groundwater protection criteria is currently of major importance in Italy. The present study has been focused on the refinement of protection measures for carbonate aquifers in central-southern Italy, taking into consideration their hydrogeological features and the results of several years of experimental research in different test sites. In these aquifers a good protection can be obtained by integrating the Italian law with specific solutions. The "map of land use restrictions" has been identified as the graphic core of a GIS-based sDSS which will aid decision-makers to protect the water resources against pollutio
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