1,720,988 research outputs found
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
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
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
SIVRAD: an integrated system for the assessment of the environmental risk from solid waste landfills - Guidelines/ SIVRAD: Un Sistema Integrato per la Valutazione del Rischio Ambientale da Discariche - Linee guida
No full textLa contaminazione delle risorse idriche sotterranee a causa di una fuoriuscita di percolato da discarica ha creato gravi problemi socio-economici ed ambientale in diversi paesi. Infatti, molte delle discariche esistenti e quelle abbandonate, ancorché non adeguatamente controllate o gestite, possono costituire una grave problematica sanitaria ed ambientale. La scelta del sito per lo smaltimento dei rifiuti deve necessariamente scaturire da uno studio rigoroso basato sulla valutazione integrata della pericolosità ambientale dell’impianto stesso, delle caratteristiche
idrogeologiche e del grado di vulnerabilità intrinseca all’inquinamento delle falde acquifere.
Nel presente lavoro viene proposto un Sistema Integrato per la Valutazione del Rischio Ambientale da Discariche di rifiuti solidi urbani (SIVRAD). L’analisi integrata della vulnerabilità intrinseca del sistema acquifero e la stima della pericolosità potenziale intrinseca consentono di valutare l’idoneità dei siti ad ospitare una discarica e di definire la priorità di bonifica ed il sistema di monitoraggio per gli impianti esistenti. Inoltre, per le nuove discariche, la metodologia descritta permette di suggerire una migliore strategia di costruzione per la tutela dell’ambiente circostante.
Infine, questo approccio metodologico è stato applicato in discariche situate in diversi contesti geologici ed idrogeologici.In recent years, the contamination of the underground resources from landfill leachates is recognised as a serious socio-economic and environmental problem in many countries. In fact, the existing not adequately controlled and abandoned sites, constitute a serious sanitary and environmental problems. The choice of the waste disposal site must necessarily arise from a rigorous study based on the joint assessment of the environmental hazard of the same plant and the hydrogeological characteristics and the degree of intrinsic vulnerability to pollution of the aquifers. In the present paper an integrated system for the assessment of the environmental risk from solid waste landfills is proposed. The integrated analysis of the intrinsic vulnerability of the aquifer system and the estimate of the intrinsic potential hazard caused by the landfill expressed in terms of danger index allow to evaluate the suitability of the sites to host a landfill and to define the reclamation priority and monitoring system for the existing landfills. As concerns new landfills, the proposed methodology could also support a better construction strategy and the protection of the surrounding environment. Finally, this methodological approach was applied in landfills located in different geological and hydrogeological contexts
Development of a Pilot Borehole Storage System of Solar Thermal Energy: Modeling, Design, and Installation
Full text linkBorehole thermal energy storage systems represent a potential solution to increase the energy efficiency of renewable energy plants, but they generally have to comply with strict regulatory frameworks, mainly due to the deliberate modification of the subsoil’s natural state. This paper presents the design, testing, and monitoring phases carried out to set up a borehole thermal energy storage (BTES) system able to exploit the excess solar heat from photovoltaic thermal (PVT) collectors. The case study is the refurbishment of a pig nursery barn, hosting up to 2500 weaners, in Northern Italy. This study aims to define a BTES suitable to develop a heating system based on renewable energy, ensuring environmental protection and long-term sustainability. The retrofitting intervention includes the installation of a dual-source heat pump (DSHP), in order to recover the solar heat stored in summer during winter. Specific constraints by the Environmental Authority were as follows: maximum storage temperature of 35 °C, authorization to intercept the shallowest aquifer at a maximum depth of 30 m, obligation of BHE grouting, and the definition of a strategy for continuous measuring and monitoring of the groundwater’s thermophysical properties. The results were used as inputs to optimize the design and installation of the integrated system with PVT, BTES, and DSHP
Groundwater characterization focusing on the seawater intrusion risk in the Metaponto coastal plain (Basilicata, southern Italy)
No full textThis paper aims to assess and model the seawater intrusion (SWI) risk in the Metaponto coastal aquifer (Basilicata, southern Italy) by characterising its intrinsic geological and hydrogeological setting and analysing the external factors such as excessive withdrawals and climate change causing modifications in the recharge process. Groundwater resources are crucial for the economic development of intensive agricultural activities and tourism in the Metaponto plain.
It represents for the entire Basilicata region a relevant economic area for its marked agricultural vocation and the presence of residential settlements, tourist facilities, and natural areas such as woodlands and wetlands. During the 20th century, the anthropogenic impacts, mainly linked to the construction of modern irrigation systems, land reclamation works, overexploitation of wells, and the development of agricultural and industrial activities, have significantly modified the plain. Indeed, the hydrogeological system was negatively impacted by the changes in land use, threatening groundwater availability and quality along the coastal plain and magnifying the risk of aquifer pollution. These modifications also increased soil salinization and SWI risks.
Nowadays, groundwater resources are particularly exposed to quantitative degradation due to the historically unfavourable climatic conditions worsened by climate change and the growing water demand and to qualitative degradation also caused by the SWI. The previous hydrochemical investigations, which examined the distribution of dissolved ions in groundwater, showed a progressive mixing between freshwater and seawater, highlighting the areas with
higher SWI proneness. The groundwater vulnerability to SWI of the entire coastal plain was evaluated through the GALDIT method.
Furthermore, numerical simulation modeling was performed for the portion of the plain characterized by a greater propensity to SWI based on the results of hydrochemical analyses and the GALDIT method application. Once the study area was selected, the geological, hydrogeological, hydrological, climatic, and hydrochemical data were acquired to define the accurate conceptual model of the study area, which is the first step for the subsequent groundwater flow numerical simulations, and the modeling of the SWI phenomenon.
The MODFLOW and SEAWAT codes were used within the Visual MODFLOW Flex 7.0 software (© 2021 by Waterloo Hydrogeologic) to implement the input data, define the boundary conditions and carry out the numerical modeling of groundwater flow with the following variable-density transport. Groundwater flow simulations were conducted in steady-state and transient conditions. Afterward, starting from the electrical conductivity values measured on selected groundwater samples, the total dissolved solids (TDS) concentrations expressed in mg/l were derived.
Subsequently, the transient transport model was implemented. Three scenarios were simulated, considering the impact of climate change on the aquifer recharge and different pumping rates effects.
The most significant hydrogeological condition on the SWI risk is attributable to the pumping rate scenario of 100 l/s. Under this condition, the SWI risk is not negligible in the future, and it can cause negative effects on the quality of the coastal aquifer groundwater. The results highlighted that the aquifer requires reliable management strategies to prevent the SWI phenomenon progression
Geomorphological mapping for liquefaction likelihood: the Piniada Valley case study (central Greece)
No full textAssessment of liquefaction susceptibility of sediments in alluvial plains is considered one of the first step for infrastructure planning, hazard mitigation, and land use management in seismically active regions. Subtle geomorphological features resulting from depositional processes could greatly contribute to estimating the liquefaction likelihood since they also dictate the type and distribution of sediments. Our case study is from the Piniada Valley (Greece), where widespread liquefaction phenomena were triggered by the 2021 Mw 6.3, Damasi earthquake. As we compiled a detailed geological map for the purposes of this investigation and correlated it to the spatial distribution of the earthquake-induced liquefaction phenomena, we observed that most of liquefaction surface evidence are related to point bars and abandoned river channels formed the last century. In particular, the areal liquefaction density was estimated at 60.7 and 67.1 manifestations per km(2), for the point bars and abandoned channels, respectively. Following this outcome, we propose a refinement of the existing liquefaction susceptibility classifications by including point bar bodies as a distinct category, characterized by a very high susceptibility to liquefaction. In addition, we discuss the correlation between the observed liquefaction manifestations and the shallow lithofacies, sand or mud prone areas, within point bars. The outcome arisen by this research is that most of liquefaction phenomena (> 70%) occurred on the area covered by coarser materials deposited on the upstream part of high sinuosity meanders
Late Quaternary hydrographic evolution in Thessaly (Central Greece): The crucial role of the Piniada Valley
No full textThe present-day hydrographic network of the Pinios River, Greece, clearly shows some major morphological and hydrographic anomalies documenting its complex evolution. A critical analysis and re-interpretation of geological and historical/modern topographic data clearly indicate an original subdivision of Thessaly into two separate endorheic hydrographic networks, Karditsa and Larissa realms. At different epochs, these two basins were partially covered by lake waters and/or marsh areas up to late Antiquity and locally/temporarily even in recent historical periods. The Piniada Valley is in between the two major (present-day) alluvial plains existing in Thessaly. The pre-infilling morphology of the valley bottom has been recently reconstructed suggesting it likely represented the lower reach of the Titarissios River draining into the Karditsa basin. These environmental-depositional conditions persisted up to Late Pleistocene when tectonic activity along the Tyrnavos and Larissa faults diverted the lower reach of this river into the Larissa area causing the abandonment of the Piniada Valley. Depending on the water discharge along the western Thessalian rivers and the consequent water level fluctuations of the Karditsa Lake, together with the gradual infilling of the basin, the Piniada Valley and especially its western sector was then largely affected by lacustrine-to-marshy conditions. This was also due to the lacking of a permanent hydrographic network draining the area. Indeed, the present-day Pinios River could form only after the prograding 'western' rivers completely infilled the Karditsa basin by generating a hydrographic network in the plain. Only in the latest stage of this process, the Piniada Valley was characterized by fluvial aggradation, causing the alluvial plain to expand eastwards finally reaching the altimetric threshold of the Kalamaki Gorge. This last phenomenon definitely established a permanent hydrographic connection between western and eastern Thessaly
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