111 research outputs found

Integrated Underground Analyses as a Key for Seasonal Heat Storage and Smart Urban Areas

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The design and performance of a shallow geothermal system is influenced by the geological and hydrogeological context, environmental conditions and thermal demand loads. In order to preserve the natural thermal resource, it is crucial to have a balance between the supply and the demand for the renewable energy. In this context, this article presents a case study where an innovative system is created for the storage of seasonal solar thermal energy underground, exploiting geotechnical micropiles technology. The new geoprobes system (energy micropile; EmP) consists of the installation of coaxial geothermal probes within existing micropiles realized for the seismic requalification of buildings. The underground geothermal system has been realized, starting from the basement of an existing holiday home Condominium, and was installed in dry subsoil, 20 m-deep below the parking floor. The building consists of 140 apartments, with a total area of 5553 m2, and is located at an altitude of about 1490 m above sea level. Within the framework of a circular economy, energy saving and the use of renewable sources, the design of the geothermal system was based on geological, hydrogeological and thermophysical analytical studies, in situ measurements (e.g., Lefranc and Lugeon test during drilling; Rock Quality Designation index; thermal response tests; acquisition of temperature data along the borehole), numerical modelling and long-term simulations. Due to the strong energy imbalance of the demand from the building (heating only), and in order to optimize the underground annual balance, both solar thermal storage and geothermal heat extraction/injection to/from a field of 380 EmPs, with a relative distance varying from 1 to 2 m, were adopted. The integrated solution, resulting from this investigation, allowed us to overcome the standard barriers of similar geological settings, such as the lack of groundwater for shallow geothermal energy exploitation, the lack of space for borehole heat exchanger drilling, the waste of solar heat during the warm season, etc., and it can pave the way for similar renewable and low carbon emission hybrid applications as well as contribute to the creation of smart buildings/urban areas

Seismic hazard for the Trans Adriatic Pipeline (TAP). Part 2: broadband scenarios at the Fier Compressor Station (Albania)

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AbstractTo ensure environmental and public safety, critical facilities require rigorous seismic hazard analysis to define seismic input for their design. We consider the case of the Trans Adriatic Pipeline (TAP), which is a pipeline that transports natural gas from the Caspian Sea to southern Italy, crossing active faults and areas characterized by high seismicity levels. For this pipeline, we develop a Probabilistic Seismic Hazard Assessment (PSHA) for the broader area, and, for the selected critical sites, we perform deterministic seismic hazard assessment (DSHA), by calculating shaking scenarios that account for the physics of the source, propagation, and site effects. This paper presents a DSHA for a compressor station located at Fier, along the Albanian coastal region. Considering the location of the most hazardous faults in the study site, revealed by the PSHA disaggregation, we model the ground motion for two different scenarios to simulate the worst-case scenario for this compressor station. We compute broadband waveforms for receivers on soft soils by applying specific transfer functions estimated from the available geotechnical data for the Fier area. The simulations reproduce the variability observed in the ground motion recorded in the near-earthquake source. The vertical ground motion is strong for receivers placed above the rupture areas and should not be ignored in seismic designs; furthermore, our vertical simulations reproduce the displacement and the static offset of the ground motion highlighted in recent studies. This observation confirms the importance of the DSHA analysis in defining the expected pipeline damage functions and permanent soil deformations

Caratterizzazione geochimica dell’acquifero alluvionale della piana di Licata (AG)

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The preliminary results concerning the hydrodynamic and geochemical conditions of the underground water resources of the region surrounding Licata (Agrigento province, Sicily) are presented. The research was focused on the unconfined aquifer (or locally semiconfined) developed in the Quaternari deposits of the Licata plain. The evolution of the Salso river and the coastal dynamics, characterised by transgresions and coast-line retreats, qualitatively and quantitatively influenced the underground water resources. In this complex geological contest, also the anthropogenic activities played a crucial role, especially the farming activity as largely testified by the occurrence of numerous greenhouses that cover most of the plain. The analysis of thermopluviometric data concernine the last 75 year allowed to obtain inferences on the climatic evolution of this region characterised by a mean annual temperature of about 18 °C of mean annual precipitations of only 454 mm. The principal feeding of the aquifer is due to infiltration from precipitations and lateral outflow from the Salso river. The high salinity of the river especially during Summer periods and the intense farming activities played a crucial role for the quality of the aquifer

Rapti-Caputo, D. (2007): Palaeo-channels and groundwater vulnerability: some considerations.

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In order to define the role played by both superficial and buried palaeo-channels within the alluvial plain of the River Po, Northern Italy, aimed to determine the intrinsic vulnerability of the aquifer systems, geomorphological, lithological, hydrogeological and geochemical data have been analysed. In particular, the relationships of these sedimentary bodies with the intrinsic vulnerability and the diffusion of polluting substances in the underground water resources have been investigated. In the eastern sector of the Po Plain and especially in the broader area surrounding Ferrara, the dominant geomorphological features are the numerous palaeo-channels. Along the natural levees of these abandoned river courses several archaeological and ancient sites were established. The space distribution of these prevailingly sandy bodies strongly influences the hydrodynamic behaviour of the aquifers as, for example, the geometrical characteristics of the superficial unconfined hydrogeological units. Indeed, along the axis of these geomorphological features the intrinsic vulnerability has been estimated to be high to extremely high (70-90%). In fact, in this superficial aquifer, important concentrations of chlorides have been detected and especially the sulphates and nitrates exceed the drinkableness limits, therefore indicating the qualitative decay of this resource mainly due to farming activities. The occurrence of sandy bodies also influences the vulnerability of the underlying confined aquifer that represents the main source exploited for the waterworks of the surrounding territory. When the axis of the principal palaeo-channels coincides with the present-day hydrographic network, as in the case of the Po di Volano, a hydraulic barrier with constant pressure is generated. As a consequence, the continuous mixing phenomena occurring between superficial and underground waters can either improve or worsen the quality of the water resources. Moreover, in this complex system, the determination of the intrinsic vulnerability of the aquifer bodies is one of the fondamental parameters to be determined before any strategic decision is taken for the integrated managment and protection of the underground resources and the environment

Caratterizzazione qualitativa dei serbatoi acquiferi

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Le caratteristiche quantitative e qualitative del patrimonio idrico sotterraneo di un territorio (acquiferi) dipendono da molteplici fattori che possono essere suddivisi in due gruppi principali: Il primo gruppo comprende fattori naturali, o primari, come quelli geologi che condizionano le caratteristiche geometriche degli acquiferi (es. spessore, estensione), idrauliche (porosità, permeabilità), ed idrogeochimiche, conseguenza del contatto tra la matrice solida (sedimenti) e fluidi (acqua). Il secondo gruppo, invece, include fattori antropici, o secondari, che possono provocare, da una parte, il degrado quantitativo delle risorse idriche sotterranee (come gli emungimenti eccessivi e non controllati per soddisfare, ad esempio, le esigenze acquedottistiche, agricole ed industriali) e, dall’altra parte, possono accelerare i processi di degrado qualitativo causato dall’eccessivo aumento delle fonti potenziali di inquinamento, sia puntuali che diffuse. In particolare, nel sottosuolo ferrarese, a causa della complessa evoluzione geologica, le risorse idriche sotterranee sono fortemente condizionate e limitate sia qualitativamente che quantitativamente dalla presenza di sedimenti permeabili deposti in ambienti lagunari, deltizi o marini. In questo tipo di sedimenti, si trovano comunemente acque primarie (i.e. sinsedimentarie), generalmente con caratteristiche salmastre che presentano, pertanto, bassi valori di resistività elettrica, generalmente minori di 5 Ohm*m, ed elevata salinità. Sulla base di numerose colonne stratigrafiche relative a pozzi per acqua e per la ricerca di idrocarburi (AGIP, 1972; SQUARZANTI, 1980) è stato possibile ricostruire, per la prima volta, l'andamento della zona di dispersione dove si verifica il passaggio graduale tra acqua dolce ed acqua salmastra, ponendo il limite in corrispondenza di valori di salinità pari a 1 g/l. Tale limite si trova a profondità variabili da pochi metri dal piano campagna, nell'area di Casaglia (20 m), a profondità di circa 50 m, nella zona di Baura, ad i 300 m, nei pressi di Copparo (VILLA et alii, 1976; SQUARZANTI, 1980). Negli anni successivi, sono state realizzate poche ricerche di carattere locale che generalmente hanno affrontato problematiche di carattere idrogeologico ed idrogeochimico. La ricerca qui descritta ha avuto come scopo principale la ricostruzione, per l'intero territorio provinciale, del comportamento e dell'evoluzione, sia idrodinamica che geochimica, delle risorse idriche sotterranee. A tal fine, è stato utilizzato un protocollo di lavoro che comprende l'analisi integrata di dati di carattere stratigrafico, idrogeologico e geochimico. Sulla base dei dati stratigrafici e fino alla profondità massima di 200 m, nel sottosuolo ferrarese sono state distinte cinque unità idrogeologiche corrispondenti all’acquifero a falda libera (A0), all'acquifero A1, generalmente in pressione e, agli acquiferi più profondi A2, A3 e A4, sempre in pressione. Le caratteristiche geologiche di questi acquiferi sono state descritte in precedenza (vedi Cap. I, § 1.3). Per la definizione della rete di monitoraggio dei pozzi che riesce a descrivere il comportamento idrodinamico e geochimico degli acquiferi ferraresi in pressione, ci si è basati sulla raccolta e sull’elaborazione di dati provenienti dall'archivio dell'ARPA e raccolti sia dalla rete di controllo attiva che da quella inattiva. Inizialmente, sulla base dell’elaborazione dei dati stratigrafici ed adottando criteri geometrici, litologici e di “capacità idrica” delle diverse formazioni, sono stati individuati i principali corpi acquiferi. Successivamente, ed utilizzando come criteri assoluti la descrizione litologica di ogni singolo pozzo e la posizione dei filtri, è stata effettuata una divisione ed una scelta dei pozzi per ogni corpo acquifero come questo è stato definito nella fase precedente. In tal modo, sono stati esclusi tutti i punti di misura e/o di campionamento per i quali non esiste una dettagliata descrizione stratigrafica, la posizione dei filtri oppure nel caso in cui i pozzi fossero filtrati in più acquiferi. Questo approccio metodologico ci ha permesso di distinguere nove pozzi filtrati esclusivamente nell’acquifero A1; sette pozzi in quello A2; un pozzo nell’acquifero A3 ed un pozzo in quello A4. Nei pozzi individuati esistono misure sistematiche della soggiacenza (profondità dell'acqua dal piano campagna), relative al periodo 1977-1998, con frequenza semestrale, mentre, solamente per alcuni di essi esistono informazioni relative allo stato chimico delle acque

Some remarks on water resources degradation and ground fissures formation in Thessaly, Greece

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During the last decades, the concomitance of a relatively dry period (i.e. low precipitations) affecting the Aegean Region and the huge increase of the cotton cultivation in large sectors of Thessaly, central Greece, forced people to search for new water resources to provide the needs. Accordingly, during the seventies and eighties, the synergy of the natural phenomenon with the inappropriate agricultural choice, was coupled with the drilling of an almost uncontrolled number of boreholes across the entire area. These water-wells that mainly exploit the alluvial multi-aquifer system of the Larissa Plain caused a significant downdrop of the piezometric level that critically exceeded the capacity to regenerate the underground natural hydraulic conditions. As a consequence, a quantitative and sometimes qualitative degradation of the water resources occurred

Some remarks on water resources degradation and ground fissures formation in Thessaly, Greece

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(i.e. low precipitations) affecting the Aegean Region and the huge increase of the cotton cultivation in large sectors of Thessaly, central Greece, forced people to search for new water resources to provide the needs. Accordingly, during the seventies and eighties, the synergy of the natural phenomenon with the inappropriate agricultural choice, was coupled with the drilling of an almost uncontrolled number of boreholes across the entire area. These water-wells that mainly exploit the alluvial multi-aquifer system of the Larissa Plain caused a significant downdrop of the piezometric level that critically exceeded the capacity to regenerate the underground natural hydraulic conditions. As a consequence, a quantitative and sometimes qualitative degradation of the water resources occurred. During the nineties, numerous ground fissures have been documented within the Larissa Plain. These superficial features have locally roduced important damages by creating open fractures in houses, stores and infrastructures, dislocations and hollows across roads and even caused a road accident. The occurrence of the phenomenon more than once, the associated damages and the awareness of the general seismogenic character of Thessaly deeply frightened the inhabitants of the region and their Authorities. A common opinion is that the production of fissures is straightforwardly and directly elated to the general lowering of the piezometric level (Soulios, 1997). In the present research, we revised all available data in order to better understand the phenomenon and the cause-effect relationships

Evoluzione geochimica e modalitĂ  di gestione di un acquifero alluvionale

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In the eastern hydrographic basin of the Po river, Northern Italy, the underground water circulation is strongly influenced by the recent geological and palaeogeographic evolution of the region, while the qualitative characteristics of the water are controlled by the depositional environment (continental, marine, etc.). Within such complex sedimentary environments, the exploitation mode plays a crucial role for the preservation of the overall aquifer quality. In order to evaluate the influence of the exploitation on the geochemical characteristics of the underground resources, hydrodynamic (piezometric level) and hydrochemical (Ph, temperature, electrical conducibility, content in HCO3, Ca, NH4, Fe, Mn, SO4, Cl, NO3, Cl, F and Br) data have been collected from the first unconfined aquifer and analysed. The investigated area corresponds to the territory surrounding Ferrara town. The elaboration of these data based on classical hydrogeological and hydrogeochemical methods, integrated with isotopic analyses allows a) to separate the principal hydrogeochemical facies, b) to recognise the occurrence of mixing phenomena between the water of the exploited aquifer and the salty water of the underlying aquifer, c) to infer about the equilibrium between the amount of pumping and the quality of the water

Influence of Climatic Changes and Human Activities on the Salinization Process of Coastal Aquifer Systems

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In the present research, two arid coastal zones of the Mediterranean region (mean annual precipitation about 440 mm/a), have been investigated for evaluating the qualitative and quantitative impact of both human activities and climatic changes on the groundwater resources and the hydrological cycle in general. In particular, the hydrographic network of the Akrotiri (Cyprus) coastal aquifer system is strongly controlled by engineering handicrafts that have induced a quality worsening of the groundwater resources. Due to over-pumping in the central sector of the area, a lowering of the piezometric level of about 15 m has been observed. As a consequence, a salinization process has occurred in the coastal sector with a mean annual salinization velocity of the salty water front varying between 47 and 97 cm/a (period 1964-1996). Due to the high salinity values, the water is at present unsuitable for irrigation use. The second case study is represented by the alluvial plain of Licata (southern Sicily, Italy), where the evolution of the Salso River (in Italian the name means ’Salty River’) and the coastal dynamics, characterised by repeated marine transgressions and regressions, qualitatively and quantitatively influenced the underground water resources. Also the anthropogenic activities played a crucial role, especially the farming activity as it is largely documented by the occurrence of numerous greenhouses covering most of the plain. The water depth of the unconfined, mainly sandy, aquifer developed in the Quaternary deposits is between 0.3 m and locally 5 m from the surface, while the principal alimentation occurs via infiltration from precipitations and lateral outflow from the Salso River
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