http://hdl.handle.net/2122/168 Ricerca nel canale cerca http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/5749 Titolo: A structural and geophysical approach to the study of fractured aquifers in the Scansano-Magliano in Toscana Ridge, southern Tuscany, Italy<br/><br/>Autori: Francese, R.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy; Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Bistacchi, A.; Dipartimento di Geologia e Geotecnologia, Università di Milano Bicocca, Milano, Italy; Morelli, G.; Geostudi Astier S.r.l., Livorno, Italy; Pasquarè, G.; Dipartimento di Geologia, Università di Milano, Milano, Italy; Praticelli, N.; Dipartimento di Geoscienze, Università di Padova, Padova, Italy; Robain, H.; Institute de Recherche pour le Développement, Bondy Cedex, France; Wardell, N.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy; Zaja, A.; Dipartimento di Geoscienze, Università di Padova, Padova, Italy<br/><br/>Abstract: Fresh water availability has recently become a serious concern in the Italian Apennines, as various activities rely on a predictable supply. Along the ridge between Scansano and Magliano in Toscana, in southern Tuscany, the situation is further complicated by contamination of the nearby alluvial aquifers. Aquifers locally consist of thin fractured reservoirs, generally within low-permeability formations, and it can be difficult to plan the exploitation of resources based on conventional techniques. An integrated study based on geological data investigated the link between tectonics and groundwater circulation, to better define the hydrological model. After the regional identification of fault and fracture patterns, a major structure was investigated in detail to accurately map its spatial position and to understand the geometry and properties of the associated aquifer and assess its exploitation potential. The subsurface around the fault zone was clearly imaged using ground probing radar, two-dimensional and three-dimensional resistivity tomography, and three-dimensional shallow seismic surveys. The vertical and horizontal contacts between the different geological units of the Ligurian and Tuscan series were resolved with a high degree of spatial accuracy. Three-dimensional high-resolution geophysical imaging proved to be a very effective means of characterising small-scale fractured reservoirs. http://hdl.handle.net/2122/5720 Titolo: FITOVERT: A dynamic numerical model of subsurface vertical flow constructed wetlands<br/><br/>Autori: Giraldi, D.; Department of Civil Engineering, University of Pisa, Pisa, Italy; De' Michieli Vitturi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Iannelli, R.; Department of Civil Engineering, University of Pisa, Pisa, Italy<br/><br/>Abstract: This paper introduces a mathematical model (FITOVERT) specifically developed to simulate the behaviour of vertical subsurface flow constructed wetlands (VSSF-CWs). One of the main goals of the development of FITOVERT was to keep the complexity of the model to an acceptable level, so as to provide a practical tool for design and operation optimization. The dynamic formulation of the model allows to simulate the typical non stationary feeding-emptying operation of VSSF-CWs. FITOVERT is able to describe the water flow through porous media in unsaturated conditions, combined with evapotranspiration; its biochemical module describes the degradation of both organic matter and nitrogen; the transport in the liquid phase is implemented for both dissolved and particulate components; the oxygen transport in the gaseous phase of the soil and its exchange with the liquid phase are also considered. As a main advantage, compared to the few currently available dedicated numerical models, FITOVERT is able to handle the porosity reduction due to bacteria growth and accumulation of particulate components, so that the clogging process is also simulated as an effect of the pore size reduction on the hydraulic conductivity of the simulated system. The performance of the model was firstly analyzed by comparison with hydrodynamic tests recorded in an experimental VSSF-CW pilot plant: tracer test were carried out in three different saturation conditions (fully saturated, partially saturated, and completely drained). FITOVERT proved to accurately simulate the hydraulic behaviour of VSSF-CWs in both saturated and unsaturated conditions. The needs for model improvements and further calibration are finally discussed. http://hdl.handle.net/2122/5714 Titolo: Hydrodynamics of vertical subsurface flow constructed wetlands: Tracer tests with rhodamine WT and numerical modelling<br/><br/>Autori: Giraldi, D.; Department of Civil Engineering – University of Pisa, Pisa, Italy; De' Michieli Vitturi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Zaramella, M.; Department of Hydraulic, Maritime, Environmental and Geotechnical Engineering – University of Padua, Padova, Italy; Marion, A.; Department of Hydraulic, Maritime, Environmental and Geotechnical Engineering – University of Padua, Padova, Italy; Iannelli, R.; Department of Civil Engineering – University of Pisa, Pisa, Italy<br/><br/>Abstract: Typical unsteady unsaturated conditions can profoundly affect the hydrodynamics of vertical subsurface flow constructed wetlands. In this study we analyzed the hydrodynamics of a 33 m2 vertical flow pilot plant, treating municipal secondary effluents. Three different saturation conditions were analyzed under several constant flux regimes: complete saturation, partial saturation with the free water table 20 cm over the bottom of the bed, and complete drainage. Tracer tests were performed in steady state conditions by dosing rhodamine WT as square input signals. Breakthrough curves were analyzed by means of both a classical residence time distribution analysis and an originally developed numerical plug-flow model with longitudinal dispersion adapted to the unsaturated conditions. We found that the degree of global mixing in the vertical flow constructed wetland increased as the water content increased; this effect was controlled by the hydraulic residence time of the system. Conversely, the degree of local mixing was inversely affected by water content; the dispersivity was 4.5, 10, and 14 cm for fully saturated, partially saturated and draining conditions, respectively. We explain the dependency of dispersivity on water content in physical terms; however, further studies are needed to mathematically include this relationship in numerical models that describe the behaviour of vertical flow constructed wetlands. http://hdl.handle.net/2122/5472 Titolo: Aspetti geologico-applicativi degli ipogei di Agrigento<br/><br/>Autori: Polemio, M.; CNR - IRPI<br/><br/>Abstract: Gli ipogei di Agrigento, dell'antica città greca Altragas, costituiscono una grandiosa opera di ingegneria idraulica e di captazione idrogeologica. Gli ipogei costituivano una rete di acquedotto che serviva, nei momenti di massimo splendore, una città abitata da circa duecentomila persone, permettendo lo sviluppo economico e sociale della più fulgida delle città della Magna Grecia. Un insieme di pozzi, cunicoli e serbatoi, scavati in una tenera roccia calcarenitica, correva con continuità lungo le pendici della valle dei Templi, a profondità dal piano campagna variabili e non superiori a 30 m. http://hdl.handle.net/2122/4538 Titolo: A Structural and Geophysical Approach to the Study of Fractured Aquifers in the Scansano-Magliano in Toscana Ridge, Southern Tuscany, Italy<br/><br/>Autori: Francese, R.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy; Mazzarini, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Bistacchi, A.; Dipartimento di Geologia e Geotecnologia, Università di Milano Bicocca, Milano, Italy; Morelli, G.; Geostudi Astier S.r.l., Livorno, Italy; Pasquarè, G.; Dipartimento di Geologia, Università di Milano, Milano, Italy; Praticelli, N.; Dipartimento di Geoscienze, Università di Padova, Padova, Italy; Robain, H.; Institute de Recherche pour le Développement, Paris, France; Wardell, N.; Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy; Zaja, A.; Dipartimento di Geoscienze, Università di Padova, Padova, Italy<br/><br/>Abstract: Fresh water availability has recently become a serious concern in the Italian Apennines, as various activities rely on a predictable supply. Along the Scansano-Magliano ridge in southern Tuscany the situation is further complicated by contamination of the nearby alluvial aquifers. Aquifers locally consist of thin fractured reservoirs, generally within low-permeability formations, and it can be difficult to plan the exploitation of resources based on conventional techniques. An integrated study based on geological investigate the link between tectonics and groundwater circulation and to better define the hydrological model. After the regional identification of fault and fracture patterns, a major structure was investigated in detail to accurately map its spatial position and to understand the geometry and properties of the associated aquifer and assess its exploitation potential. The subsurface around the fault zone was clearly imaged through Ground Probing Radar, 2D and 3D resistivity tomography, and 3D shallow seismic surveys. The vertical and horizontal contacts between the different geological units of the Ligurian and Tuscan series were resolved with a high degree of spatial accuracy. 3D high-resolution geophysical imaging proved to be a very effective means for characterising small-scale fractured reservoirs. http://hdl.handle.net/2122/4131 Titolo: GEOCHEMICAL CHARACTERIZATION OF THERMAL AND COLD GROUNDWATERS OF METHANA PENINSULA (PELOPONNESUS, GREECE)<br/><br/>Autori: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Brusca, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Kyriakopoulos, K.; University of Athens, Dept. Geology and Geoenvironment; Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Michas, G.; University of Athens, Dept. Geology and Geoenvironment; Papadakis, G.; University of Athens, Dept. Geology and Geoenvironment<br/><br/>Curatori: Migiros, G.; Agricultural University of Athens, Dept: Sciences; Stamatis, G.; Agricultural University of Athens, Dept: Sciences; Stournaras, G.; University of Athens, Dept. of Geology and Geoenvironment<br/><br/>Abstract: A comprehensive hydrogeochemical study of the cold and thermal groundwaters of the presently quiescent volcanic system of Methana was undertaken collecting 59 natural water samples during the period 2004-2007. Methana is a peninsula whose climatology and hydrology can be compared to the nearby small islands of the Aegean Sea. Similarly the chemical and isotopic composition of its water is dominated by the mixing of seawater with meteoric water. But the simple mixing trend is modified by water-rock interaction processes, enhanced by the dissolution of endogenous CO2, leading to strong enrichments in Alkalinity, Calcium, Barium, Iron and Manganese. http://hdl.handle.net/2122/2504 Titolo: Moisture source in the Hyblean Mountains region (south-eastern Sicily, Italy): evidence from stable isotopes signature<br/><br/>Autori: Grassa, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Valenza, M.; Dipartimento CFTA, Universita` di Palermo, Palermo<br/><br/>Abstract: Here the authors present results of an isotope study on precipitation collected during a 2-a period from a rain-gaugenetwork consisting of 6 stations located at different elevations in the Hyblean Mountains (HM) region, in south-easternSicily. The slope of the local meteoric water line (dD = 6.50 d18O + 9.87) obtained for the region suggests that precipitationis affected by evaporation during rainfall events. The main variations in rainwater isotope composition are due to seasonaleffects and elevation. An average 2H excess value of +21.2&was found for precipitation events less affected by evaporation(i.e. when the rainfall was >65 mm/month). The spatial distribution of O isotope composition of precipitation shows anegative gradient from east and south to the inner areas. The depositional rate of Cl, used as a tracer of the origin ofair masses, is highest at the coastal rain-gauges (SR and MRG stations) and lowest on the northern flank of the HM region(SC station). Based on these findings, a model is proposed for the origin of precipitation in the HM region, which assumesthat a Mediterranean-derived component is the main source of moisture in the studied area. D/H and 18O/16O ratios ofinferred meteoric recharge waters were also compared with the isotope composition of waters collected from the main localsprings and wells. The best linear fit of the d18O vs dD relationship for Hyblean groundwater is dD = 4.85 d18O–2.01. Theenrichment of heavy isotopes in Hyblean groundwater is probably due to evaporation occurring after precipitation eventsor to a recharging contribution from surface waters (lakes or rivers) enriched in heavy isotopes. http://hdl.handle.net/2122/2500 Titolo: Quality and potentiality of water resources in an area intensively cultivated of the Sicilian hinterland<br/><br/>Autori: Hauser, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Cusimano, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Vassallo, M.; Dipartimento di Chimica e Fisica della Terra, Universita` degli Studi di Palermo, Palermo, Italy.; Capasso, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia<br/><br/>Abstract: A hydrogeochemical study, along with a geological and hydrogeological support, permitted the grounwater circulation in the canicattì hydrogeological basin, which is located in the inner part of sicily to be reconstructed. http://hdl.handle.net/2122/516 Titolo: Groundwater radon measurements in the Mt. Etna area<br/><br/>Autori: D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Vita, F.; Dipartimento CFTA, Universita` di Palermo, via Archirafi 36, 90123 Palermo, Italy<br/><br/>Abstract: Radon levels were measured in 119 groundwater samples collected throughout the activevolcanic area of Mt. Etna by means of a portable Lucas-type scintillation chamber. The measuredactivity values range from 1.8 to 52.7 Bq l 1. About 40% of the samples exceed themaximum contaminant level of 11 Bq l 1 proposed by the USEPA in 1991. The highest radonlevels are measured in the eastern sector of the volcano, which is the seismically most activezone of the volcano. On the contrary the south-western sector, which is both seismically activeand a site of intense magmatic degassing, display lower radon levels. This is probably due tothe formation of a free gas phase (oversaturation of CO2) that strips the radon from the water.Comparison of the data gathered at Mt. Etna with those of other areas indicates that 222Rnactivity in groundwater is positively correlated with both the content of parent elements in theaquifer rocks and the temperature of the geothermal systems that interacts with the sampledaquifers. http://hdl.handle.net/2122/513 Titolo: Natural and anthropogenic factors affecting groundwater quality of an active volcano (Mt. Etna, Italy)<br/><br/>Autori: Aiuppa, A.; Dipartimento CFTA, Universita` di Palermo; Bellomo, S.; Dipartimento CFTA, Universita` di Palermo; Brusca, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Federico, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia<br/><br/>Abstract: New geochemical data on dissolved major and minor constituents in 276 groundwater samples from Etna aquifers reveal the main processes responsible for their geochemical evolution and mineralisation. This topic is of particularinterest in the light of the progressive depletion of water resources and groundwater quality in the area. Multivariate statistical analysis reveal 3 sources of solutes: (a) the leaching of the host basalt, driven by the dissolution of magmaderived CO2; (b) mixing processes with saline brines rising from the sedimentary basement below Etna; (c) contaminationfrom agricultural and urban wastewaters. The last process, highlighted by increased concentrations of SO4,NO3, Ca, F and PO4, is more pronounced on the lower slopes of the volcanic edifice, associated with areas of high population and intensive agriculture. However, this study demonstrates that natural processes (a) and (b) are also very effective in producing highly mineralised waters, which in turn results in many constituents (B, V, Mg) exceeding maximum admissible concentrations for drinking water.