130,684 research outputs found
Rapti-Caputo, D. (2007): Palaeo-channels and groundwater vulnerability: some considerations.
No full textIn 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
Geochimica isotopica
No full textNegli ultimi decenni, gli isotopi stabili dell’ossigeno e dell’idrogeno sono comunemente utilizzati per stabilire l’origine delle acque e le aree di alimentazione degli acquiferi; mentre, il trizio e gli isotopi del carbonio sono utilizzati per la valutazione dei tempi di residenza delle acque nei serbatoi.
La caratterizzazione isotopica delle risorse idriche sotterranee, che si sviluppano nel territorio ferrarese, con particolare interesse al primo (A1-I) e secondo acquifero in pressione (A2-I), è stata realizzata, tramite l’elaborazione, di dati provenienti da una rete di monitoraggio costituita da 18 pozzi (database ARPA, progetto SINA; RAPTI CAPUTO, 2000). In particolare, sono stati utilizzati dieci campioni d’acqua per la caratterizzazione isotopica del sistema acquifero A1-I ed otto per quello A2-I. Nei campioni raccolti sono stati analizzati i rapporti isotopici 18O/16O, D/H ed il contenuto il tritio (T), carbonio-14 (14C) e carbonio-13 (13C).
Tenendo in considerazione tutti i campioni, l’analisi dei dati isotopici ci ha permesso di osservare valori del rapporto 18O/16O compresi tra -10,86 e -7,44, mentre, il rapporto isotopico D/H mostra valori compresi tra -72,79 e -48,99.
La distribuzione dei valori isotopici relativi all’ossigeno e all’idrogeno (fig. 32) riflette, in generale, la presenza di acque di molteplice origine, da padano-alpina, ad appenninica e fino ad acque 'locali'
Hydrogeology of a Volcano-Sedimentary Multi-Aquifer System: The Skydra, Northern Greece, Case Study
No full textDue to climate change, water scarcity, and overexploitation of aquifers, the sustainable management and protection of groundwater resources will be one of the main challenges in the future. Therefore, the knowledge of hydrogeological characteristics, which must be as robust as possible, becomes crucial for defining groundwater management plans. On the other hand, the earliest evidence of the fertile plains and abundant water resources of Skydra and its surroundings dates back to the Neolithic period (6500-3200 B.C.), confirming the area's current agricultural vocation and productivity. In this perspective, the aim of the present study is to define the conceptual hydrogeological model of a complex confined multi-aquifer system characterizing the volcano-sedimentary deposits of the Skydra area, northern Greece. In particular, the architecture of the hydrostratigraphic units, the hydraulic parameters, and the hydrodynamic behavior of the multi-aquifer system were analyzed. The geological, geomorphological, and structural evolution affecting the area has influenced the geometric and hydraulic characteristics of the aquifer, and consequently its productivity. The thickness of the multi-aquifer system varies between 25.0 and 94.5 m and the hydraulic conductivity, calculated through the analysis of data from 72 pumping tests, and the application of empirical method (42 wells), ranges between 2.2 10-6 and 2.5 10-3 m/s. Higher hydraulic conductivity values are calculated in areas where tuffaceous formations are fractured and/or interlayered with sandy layers; while lower values occur where tuffs present only primary porosity and are interspersed with frequent clay layers. In the central area, due to overexploitation of the aquifer, an annual piezometric level drop of approximately 6 m has been recorded. The information acquired could serve as the basis for the sustainable development of groundwater resources in the test area and could also be applied in other similar hydrogeological settings
Influence of Climatic Changes and Human Activities on the Salinization Process of Coastal Aquifer Systems
No full textIn 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
A multidisciplinary approach for exploring shallow geothermal resources: the Mirandola case study
No full textAt present, energy is provided by a co-generator fuelled with gas, while for the new plant they decided to exploit the shallow geothermal capacity of their subsoil. For better defining the workflow of this problem-solving process, we used the above mentioned environmental and energy needs as starting points and integrated the process with design-thinking methodologies. The test site is located within the northern alluvial plain of the Modena Province, north Italy. Notwithstanding the apparently uniform morphological setting, the stratigraphy and the hydrogeological conditions have been strongly influenced by the recent tectonics causing important heterogeneities in the subsoil. The most energy-intensive customer of the district heating is represented by the head-quarter offices of the Company itself, where the building's thermal needs alone consist of approximately 750 MWh/year for heating and the production of domestic hot water. It should be mentioned that at present these also need more than 500 MWh/year for summer cooling, which is provided by another fossil fuelled machine
Geothermal anomalies in a sector of the eastern Po Plain
No full textThe European and National strategies for the climate and the energy have as major targets the decarbonisation process before 2050 and the drastic reduction of the PM10 concentration in the Po Plain. In order to achieve these goals, the request, the exploitation, the use and the diffusion of renewable energies should greatly increase in the next future. Due to the recent evolution of technological plants, like district heating, the low-to-medium enthalpy geothermal plants perfectly fulfil the above needs with important environmental, economic, societal, and health benefits. The present research is motivated to contribute to the above needs and particularly to the characterization of the geothermal reservoirs existing in the broader Ferrara-Modena territory, Northern Italy, which hosts in the subsoil some major tectonic structures with a high geothermal potential, like the Ferrara anticlin
Vulnerability of the aquifer system: considerations on a methodological approach.
No full textThe worldwide development of past civilisations as well as the recent socio-economical evolution of Nations is based and strongly controlled by the availability of water. The Mediterranean Basin that during the last decades has been characterised by a semi-arid climate is not an exception. In this area, the occurrence of wide aquifers both in limestone rocks and alluvial deposits favour the accumulation of important amounts of water resources. However, this opulence in underground waters is often compromised by an abuse of pumping and by local but diffused polluting phenomena having several causes (urban, farming, facto-ries, etc.). In Italy, only the 40% of the total amount of the potentially exploitable water re-sources, both superficial and underground, is effectively exploited. In fact, the remaining 60% is in practice not used because of qualitative and economical problems. Due to the general setting and the specific characteristics, the aquifers are frequently vulnerable to superficial polluting sources. In particular, the vulnerability of the underground resources is a function of a) the hydrolithological, hydrostructure and hydrogeological conditions of the system; b) the pedological characteristics of the soils; c) the recharge conditions; d) the groundwater inflow-outflow processes and e) the physical and hydrochemical processes that influence the natural quality of waters (Civita and De Maio, 1977). In the last decades, several methods to evaluate the intrinsic vulnerability of the aquifer system have been development based on a) the zona-tion of homogeneous areas with a similar degree of vulnerability (e.g. Albinet and Margat, 1970) and b) the parametric systems separated in a matrix system, a point count system, a point count system model and an environmental evaluation system (Foster, 1987; Aller et al., 1987; Dee et al., 1973; Civita and De Maio, 1997).
The present research is devoted to the evaluation of the intrinsic vulnerability to pollution for two case studies characterised by a different density and overall quality of basic information. The first area is represented by the carbonate aquifer of the High Basento Valley (Basilicata, Southern Italy), while the second case study is the alluvial system surrounding the town of Ferrara, characterised by an unconfined aquifer (Eastern Po Plain, Northern Italy). For both areas, we define the conceptual hydrogeological model before applying the more suitable methodological approach allowing us to recognise the sectors characterised by the higher degree of pollution risk
Environmental and energetic implications of the geothermal anomalies in the Eastern Po Plan
No full textThe present research is devoted to contributing on the characterization of the low-to-medium enthalpy geothermal resources existing in the broader Ferrara-Modena territory, Northern Italy. To achieve the goal, first, we analysed temperature data in selected deep boreholes to estimate the local thermophysical parameters of the underground. In order to discriminate the influence of the circulation fluids and then estimate the real temperature values of the surrounding rocks, we applied different methodological approaches. Secondly, different deep seismic reflection profiles for hydrocarbon exploration were analysed to evaluate the main lithological formation and tectonic assessment. Thirdly, we elaborated hydrochemical data obtained from borehole and temperature logs measurement to estimate the influence of the deep geothermal fluids on the shallow aquifer systems. Finally, the integrated analysis of all data allowed to infer both the horizontal and vertical temperature distributions, which are clearly strongly affected by the geological, hydrogeological and tectonic evolution of the eastern sector of the Po Plain, and especially to recognize the area with a highest geothermal potential within the region
Vulnerability of the aquifer system: considerations on a methodological approach.
No full textThe protection of groundwater, now exposed to contamination and over-exploitation in the
industrialised world, is one of the major issues in modern groundwater resource planning. In particular, in the
semi-arid areas of the Mediterranean basin, for a better management and protection of the water resources, it is
very important the assessment and the mapping of groundwater vulnerability to contamination. In this paper,
we present the result and the problem relative to realization of vulnerability maps in different geologicalhydrogeological
and human-pressure conditions. Firstly, in order to define the conceptual hydrogeological
model of the area, geological, stratigraphic, geomorfological, hydrological and hydrogeological data are
collected and elaborated. Secondly, by using the most suitable method for the local hydrogeological condition,
among those available from the literature, the created database is implemented in a GIS to estimate the intrinsic
vulnerability of the aquifer systems
Vulnerabilità all'inquinamento dell'idrostruttura carbonatica dei Monti Arioso-Pierfaone nell'alta valle del Fiume Basento in Basilicata.
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