An easy-To-use method for assessing nitrate contamination susceptibility in groundwater

This research presents a methodology for assessing nitrate contamination susceptibility in groundwater using thematic maps, derived mainly from the land use map and from statistical data available at national/regional institutes of statistics (especially demographic and environmental data). The methodology was applied in a large area of southern Italy encompassing 4 alluvial and volcanic groundwater bodies, with high concentrations of NO3. The Potential Nitrate Contamination is believed to derive from three sources: agricultural, urban, and periurban. The first one is related to the use of fertilizers. For this reason the land use map was reclassified on the basis of the crop requirements in terms of fertilizers to obtain the Agricultural Potential Nitrate Contamination (APNC) map.The urban source considers leakages from the sewage network and, consequently, it depends on the anthropogenic pressure, expressed by the population density, particularly concentrated in the urbanized areas (Urban Potential Nitrate Contamination (UPNC)map). The periurban sources include unsewered areas, especially present in the periurban context, where illegal sewage connections coexist with on-site sewage disposal (cesspools, septic tanks, and pit latrines) (Periurban Potential Nitrate Contamination (PuPNC) map). The Potential Nitrate Contamination (PNC) map is produced by overlaying the APNC, UPNC, and PuPNC maps. The map combination process is straightforward, being an algebraic combination: the output values are the arithmetic average of the input values. The final pollution susceptibility (RISK) map is obtained by combining the PNC map with the groundwater contamination vulnerability (GwVu) map. The methodology, successfully applied in the study area with a relatively good correlation between the nitrate contamination susceptibility map and the nitrate distribution in groundwater, appears to be effective and have a significant potential for being applied worldwide

Hydrogeochemical characterization of the urban coastal aquifers of Napoli (southern Italy): an overview

The presence of phenomena of salt water intrusion in aquifers located in coastal urbanized areas, especially depended on the use of groundwater, is a widespread problem in the world. The study deals with the large coastal belt of the Municipality of Naples(southern Italy), located between the volcanic areas of the Somma-Vesuvius (East) and the Phlegrean Fields (West). Three different coastal sectors were analysed: the plain of Bagnoli-Fuorigrotta (BF), the area of Mount Echia (E) and the area of Eastern Naples (EN). Acquired chemical data allowed of the identification of three different groundwater chemical features and the prevalent absence of sea water contamination, mainly due to the low use of these waters. The study highlighted the chief role of the presence of faults in this volcanic area, favouring the upwelling of gases (prevalently CO2). These gases increase the groundwater reactivity causing, in the Mount Echia sector, the presence of sulphurous mineral waters and, in the Bagnoli-Fuorigrotta sector, determining the alteration of the natural relationship between freshwater and saltwater. Moreover, in the Eastern Naples sector, the occurrence of lenses of peat, which play an important hydrogeologic role as aquiclude, can determine reducing condition in the aquifers, with high concentrations in Fe and Mn

The hydrogeological monitoring of an experimental site in Campania focused at the evaluation of the contaminants transfer from the soil

Hydrochemical model , pyroclastic rocks, recharge time, Teverola, Campani

Using statistical analyses for improving rating methods for groundwater vulnerability in contamination maps

With the aim of developing procedures coping with the disadvantages and emphasising the advantages of existing rating methods and the use of statistical methods for assessing groundwater vulnerability, we propose to combine the two approaches to perform a groundwater vulnerability assessment in a study area in Italy. In the case study, located in an area of northern Italy with both urban and agricultural sectors, keeping the structure of the DRASTIC rating method, we used a spatial statistical approach to calibrate weights and ratings of a series of variables, potentially affecting groundwater vulnerability. In order to verify the effectiveness of these procedures, the results were compared to a non-modified approach and to the map resulting from the ‘‘Time–Input’’ method, highlighting the advantages that can be obtained, and defining the general limit of these applications. The revised method shows a more realistic distribution of vulnerability classes in accordance with the distribution of wells impacted by high nitrate concentration, demonstrating the importance of taking into account the specific hydrogeological conditions of the area

A Firenze messe le basi per una Piattaforma internazionale per una corretta gestione delle risorse idriche sotterranee

II 10 dicembre, in occasione della Giornata dei Diritti umani si è tenuto a Firenze, nella monumentale Sala dei Cinquecento di Palazzo Vecchio, il 1° Workshop su: "Uso delle risorse idriche sotterranee in periodi siccitosi. Esperienze dalla Toscana al resto del mondo", organizzato dalla Sezione Italiana dell'Associazione Internazionale degli Idrogeologi (IAH) con Aquifera onlus e patrocinato, oltre che dalla Regione Toscana e dal Comune di Firenze (che ha gentilmente concesso l'uso della sala), dalla Società Geologica Italiana (SGI), dal Consiglio Nazionale dei Geologi (CNG) e dal'IAH-Burdon Groundwater Network for International Development [...]

An integrated approach for the delimitation of a groundwater basin: The case study of the Conca di Acerno (Campania, Southern Italy)

The Conca di Acerno is an intra-Apennine graben located in the south-western sector of the carbonatic Mts. Picentini (Campania, province of Salerno). In the past, the graben hosted a lake basin, filled lat a later stage by fluvial-lacustrine deposits, cut in turn by the Tusciano River and by the Isca della Serra Creek. The town of Acerno lies on one of the terraced surfaces. Along the banks of the Tusciano River and the Isca della Serra Creek, on the outskirts of the town of Acerno, two important groups of springs (with a total discharge of about 1000 L/s) are located and tapped by the Ausino Consortium public water supply. All previous data concerning the various groundwater catchment plants, implemented by new measurements (piezometric, hydrochemical and isotopic - 18O and 2H), have led to improve the knowledge on the various hydrogeological aspects related to the origin of the springs and their recharge areas. In detail, the main achieved results are the following: • all the springs are, in different ways, exits of the same groundwater body hosted within the dolomitic bedrock, buried by the detritic-alluvial deposits of the graben; • a significant groundwater flow to the Tusciano River comes from the right bank of the river, in contrast to the present hydrogeological interpretation; • the limits of the groundwater basin feeding the Acerno spring groups have been established more accurately, especially on the basis of the groundwater balance

Discovery of spin-phase dependent QPOs in the super-critical accretion regime from the X-ray pulsar RX J0440.9+4431

RX J0440.9+4431 is an accreting X-ray pulsar (XRP) that remained relatively unexplored until recently, when major X-ray outburst activity enabled more in-depth studies. Here, we report on the discovery of ${\sim}0.2$ Hz quasi-periodic oscillations (QPOs) from this source observed with $Fermi$-GBM. The appearance of QPOs in RX J0440.9+4431 is thricely transient, that is, QPOs appear only above a certain luminosity, only at certain pulse phases (namely corresponding to the peak of its sine-like pulse profile), and only for a few oscillations at time. We argue that this newly discovered phenomenon (appearance of thricely transient QPOs -- or ATTO) occurs if QPOs are fed through an accretion disk whose inner region viscosity is unstable to mass accretion rate and temperature variations. Such variations are triggered when the source switches to the super-critical accretion regime and the emission pattern changes. We also argue that the emission region configuration is likely responsible for the observed QPOs spin-phase dependence.Comment: 5 + 2 appendix pages. Accepted on A&A. Proofs versio

Hydrogeological Features and Sustainable Use of Geothermal Resources: Selected Case Studies in Italy

Within the framework of the activities aimed at studying current and future exploitation and the related sustainability of geothermal resources, and considering the key role hydrogeology plays in the study of geothermal systems and design of installations, in October 2012 the Working Group IDROGEOTER was set-up within the IAH (International Association of Hydrogeologists) Italian Chapter. The first activity of IDROGEOTER‘s workplan is the analysis of state of the art in current use of low-to high enthalpy geothermal resources in Italy and of the hydrogeological settings resulting from features (e.g.: hydrostratigraphy, hydraulic and hydrodynamic conditions, hydrogeochemistry, …) influencing the availability of the resource and the potential of the systems. Detailed studies supporting the possible optimization of the use of geothermal resources, carried out in different areas (see figure) and under different hydrogeological conditions in Italy, are described in the paper. In the Piedmont Region (NW Italy) several experimental sites have been investigated in order to assess the potential subsurface effects of open-loop Groundwater Heat Pumps (GW-HPs) plants for the cooling and heating of buildings. A comparison between field measures and numerical modelling results reveals that the most important aquifer parameters affecting the developing of the Thermal Affected Zone (TAZ) around the injection wells are those related to advective heat transfer. The Lombardy Region (N Italy) is currently the most populated and industrialized region in Italy and therefore the area where the highest number of GWHP plants (open and closed loop) are installed, from which a representative sample will be selected with the objective of identifying the critical hydrogeological factors contributing both to the geothermal potential and to a sustainable use of the resource. In the Veneto Region (NE Italy), the Euganean Geothermal Field is the most important thermal field in northern Italy (about 250 active wells) and the thermal waters (65-86 °C) are mainly used for spas; recently, a new conceptual model of the Euganean Geothermal System has been proposed and tested in a numerical model; with regard to low enthalpy, studies on sites potentially suitable for closed-loop and open-loop systems, together with data from automated monitoring of several wells, could be used for advanced analysis of different hydrogeothermal systems. Research activities in the Lazio Region (Central Italy) focus also on low enthalpy and are specifically aimed at the mapping of the geothermal potential of aquifers, and at pilot studies of sites characterized by gravel aquifers, alluvial Holocene deposits of the Tevere River and alluvial pre-volcanic Pleistocene deposits. In the Campania Region (S Italy - Mondragone plain), in the framework of the geothermal exploration programme “VIGOR” (Evaluation of Geothermal Potential in Convergence Region), a groundwater balance, verifying the recharge area of thermal springs (temperature 33-54 °C) connected to a large carbonate aquifer, has permitted the identification of the most suitable area in which to drill a geothermal well. In the Apulia Region (SE Italy) the thermal field trends consequent to groundwater advection and the influence of seawater intrusion have been reconstructed for two karstic coastal aquifers (Murgia and Salento) at various elevation between -5 and -100 m amsl. These reconstructions are intended to provide required base knowledge for correctly implementing low enthalpy HP plants in the saturated zones. Further studies and inventory of data and applications will be part of the activities of IDROGEOTER, which will also include the preparation of a proposal of guidelines for hydro-geothermal studies

"Acque calde" ai congressi di Mórahalom (Ungheria) e a Idrovulc2013

notizie dalla IAH Itali