1,720,971 research outputs found
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
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
Some remarks on water resources degradation and ground fissures formation in Thessaly, Greece
No full text(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
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
Some remarks on the formation of ground fissures in Thessaly, Greece
No full textDuring 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.
During the nineties, numerous ground fissures have been documented within the Larissa Plain. These superficial features have locally produced 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 related to the general lowering of the piezometric level. In the present research, we revised all available data in order to better understand the phenomenon and the cause-effect relationships
Strategic groundwater resources in the Tagliamento River basin (northern Italy): hydrogeological investigation integrated with geophysical exploration.
No full textYperia Krini spring (central Greece): Inferences on climatic changes from its 2000 years of history
No full textThe development of past civilizations and the foundation of towns have always been
strictly linked to the availability of water. Following the Actualism principle and based on the
hydraulic capacity, we analyse more than 2000 years of evolution of Yperia Krini spring in
Thessaly (Greece), by investigating possible variations in terms of water discharge. In particular,
the integrated analysis of geological, hydrological, hydrogeological and historical data relative to
the spring, called by Sophocles a ‘gift of God and source of life’, allowed us to understand the role
played by both climatic variations and anthropogenic activities on the behaviour and the characteristics
of the local underground water resources within the Thessalian plain
Evaluation of the pollution risk of the groundwater due to landfill in karstic areas of Kerkyra Island (Greece)
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