Search results for "Aquifer"

Study And Monitoring Of Salt Water Intrusion In The Coastal Area Between Mazara Del Vallo And Marsala (South-Western Sicily)

2007

In this chapter the study of a coastal aquifer located in South-Western Sicily (between the towns of Marsala and Mazara del Vallo) is presented, carried out using geochemical, hydro-geological and geophysical techniques. The aquifer has been over-exploited to the point of being subject to intense and worrisome salt-water intrusion. A preliminary chemical and physical characterization of the waters was carried out; this included measuring their conductivity and their chloride content. This allowed to detect the marine intrusion wedge in the coastal aquifer. A series of electromagnetic soundings, suitably calibrated by well logs, were effected in the whole area and allowed to create a 3D inte…

Strategic Behavior and Efficiency in the Common Property Extraction of Groundwater

2002

Groundwater has always been regarded as a common property resource where entry is restricted by land ownership and private exploitation is inefficient. In 1980, Gisser and Sanchez presented a first estimation of this inefficiency, cornparing socially optimal exploitation with private (competitive) exploitation using a model with linear water demand, average extraction cost independent of the rate of extraction and linearly decreasing with respect to the water table level. They characterized the private exploitation of the aquifer assuming that farmers are myopic and choose their rate of extraction to maximize their current profits, whereas optimal exploitation is obtained by maximizing the …

Dissolution Process: When Does the Process Start

2019

Dissolution process is a complex phenomenon controlled by several factors as like lithology, porosity, stress orientation, environmental conditions and networks of fractures. Then, fault zone and fractures play an important role in fluid circulation and in dissolution, acting as barriers or conduits. In fact, the fault zone has a high permeability only in the early stages of the movement, but shortly the process of recrystallization and reprecipitation reduces the permeability greatly within them. Despite this, traditionally (Cucchi and Forti in In Att. e Mem. Comm. Grotte “E: Boegan” 87–93, 1988; Bini et al. in Varese Lake and the Quaternary 6:3–14, 1993; Ferrarese and Meneghel in Aspetti …

Geochemical characterization and health risk assessment in two diversified environmental settings (Southern Italy).

2021

An integrated approach using chemical and microbial indicators has been tested in two different sites of the Campania Plain (Southern Italy) with different land use covering and different hydrogeological features in order: (1) to define the water-rock interaction processes, (2) to differentiate sources of pollution in a detailed way (3) to evaluate the degree of water quality in the studied alluvial aquifer and (4) to identify the most worrying elements for human's health. Groundwater have showed a HCO3-Ca signature for both investigated sites, and a progressive enrichment in alkali ions has been highlighted moving from the boundary of the plain toward the coastal areas, due to groundwater …

Geochemical characterization of surface waters and groundwater resources in the Managua area (Nicaragua, Central America)

2008

This paper reports new geochemical data on dissolved major and minor constituents in surface waters and ground waters collected in the Managua region (Nicaragua), and provides a preliminary characterization of the hydrogeochemical processes governing the natural water evolution in this area. The peculiar geological features of the study site, an active tectonic region (Nicaragua Depression) characterized by active volcanism and thermalism, combined with significant anthropogenic pressure, contribute to a complex evolution of water chemistry, which results from the simultaneous action of several geochemical processes such as evaporation, rock leaching, mixing with saline brines of natural or…

Sensitivity Analysis Of Multi-Electrode Arrays For Characterizing The Non-Saturated Zone In Groundwater Vulnerability Assessment

2009

The near-surface environment acts as a filter and buffer for contaminants introduced from the surface by anthropogenic activities. For this reason there is a great need to improve our understanding of the shallow subsurface taking into account the increasing demand for vulnerability maps which illustrates the exposure of aquifers against pollution. These maps are designed to show areas of greatest potential for groundwater contamination on the basis of local subsurface conditions. A shallow, unconfined sand-and-gravel aquifer is highly vulnerable to pollutants because rapid recharge gives little time to contaminants to degrade naturally or be adsorbed before reaching the aquifer. Conversely…

Vulnerability map of the Nebrodi Mts Area (Sicily)

2007

A geophysical and geochemical approach for seawater intrusion assessment in the Acquedolci coastal aquifer (Northern Sicily)

2007

Vertical electrical sounding (VES’) surveys and chemical analyses of groundwater have been executed in the coastal plain of Acquedolci (Northern Sicily), with the aim to circumscribe seawater intrusion phenomena. This urbanized area is representative of a more general problem interesting most of Mediterranean littoral areas, where intensive overdraft favors a heavy seawater intrusion through the coastline. Aquifer resistivity seems decisively to be conditioned by the chlorine and magnesium content in the main aquifer of the region. Schlumberger VES’, together with piezometric and chemical–physical information of groundwater, allowed us to perform hydrogeological and geophysical elaborations…

Sulfuric acid speleogenesis (SAS) close to the water table: Examples from southern France, Austria, and Sicily

2016

Caves formed by rising sulfuric waters have been described from all over the world in a wide variety of climate settings, from arid regions to mid-latitude and alpine areas. H2S is generally formed at depth by reduction of sulfates in the presence of hydrocarbons and is transported in solution through the deep aquifers. In tectonically disturbed areas major fractures eventually allow these H2S-bearing fluids to rise to the surface where oxidation processes can become active producing sulfuric acid. This extremely strong acid reacts with the carbonate bedrock creating caves, some of which are among the largest and most spectacular in the world. Production of sulfuric acid mostly occurs at or…

Competitive versus efficient extraction of a common property resource: The groundwater case

2001

Abstract In this paper socially optimal and private extraction of a common property aquifer are compared. Open-loop equilibrium and feedback equilibrium in linear strategies have been computed to characterize private extraction. The use of these two equilibrium concepts allows us to distinguish between cost and strategic externalities as long as the open-loop solution captures only the cost externality, and the feedback solution captures both. The results show that strategic behaviour increases the overexploitation of the aquifer compared to the open-loop solution. However, if the groundwater storage capacity is large, the difference between the socially optimal and private extraction, the …