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HYDROGEOLOGICAL SURVEYS AND ANALYTICAL APPLICATIONS OF THE VENETIAN AQUIFER SYSTEM. IMPLEMENTATIONS OF SAFETY MEASURES FOR THE VENICE LAGOON AREA
Get PDFIn the study area (Venetian hinterland, Porto Marghera) there is an average of a few hundred artesian wells (80-350 m in depth) drilled between 1910-1970 and later abandoned. These wells represent a means through which the artesian waters rise; therefore a dispersion process takes place between the groundwaters in the Shallow Aquifer System (0-80 m) and those in the deep artesian aquifers (Artesian Aquifer System, 80-350 m below ground level), in which the hydraulic head has steadily risen for the last 40 years. In this instance the shallow aquifers (about 0-30 m) could be subjected to a recharge through the abandoned wells. This recharge effect adds itself to a hydro-geological system greatly influenced by anthropic activities, such as: safety measures by means of a drainage system made up of many pumping stations which guard both the phreatic level in wide-spread areas and the hydraulic head; diaphragm walls in the whole area of Porto Marghera both near the lagoon border and the inland. The diaphragm wall goes down to 15-20 m in depth.
These diaphragm walls should remove the superfluous groundwaters that – by passing through highly polluted lands – must necessarily be dealt with and treated in suitable plants.
The spontaneous rise of the groundwaters through abandoned wells due to the increase of the hydraulic head in the deep aquifers has not been studied in depth from a scientific point of view.
The analytical and numerical models available in scientific literature mainly deal with the definition of a system made up of abandoned deep wells, through which fluids may run because of the injection of fluid waste or carbon dioxide through injection wells.
Starting from the analytical solutions suggested by different authors new ones have been achieved which may be more effectively adapted to the unusual problems occurred in defining the vertical flow through abandoned wells.
The use of these solutions requires the analysis of a series of hydrogeological parameters. The most important is the geometrical reconstruction of the aquifers involved. An updated hydro-geological model of the whole study area is necessary. As there is no data on explorations at such depths, an updated hydrostratigraphic reconstruction has been developed of the only core drilling on which there is a lot of information: the Ve-1 drilled at 951 m in 1971. The reference hydrostratigraphic sequence required an analysis of the earliest scientific publications on Ve-1 on a sedimen-tological, palynological and magnetostratigraphic level.
The data from the stratigraphies of some wells built through full drilling has been used in a new software package completed in this paper (modalstrata). Modalstrata allows the establishment of a mean stratigraphy from a series of reference verticals in a certain area. In the areas in which there is not much stratigraphic data, the geophysical method of passive seismic was used which allows the identification of lateral continuity in the main reflectors.
This hydrostratigraphic model is confirmed by the comparison of a first hydrostratigraphic series developed for Ve-1.
Therefore the updated hydrostratigraphic model of the study area allowed the definition of the geometries included in the analytical solutions in order to identify the leakage rates in the spe-cific instance a sufficient number of hydrogeological parameters are known.
The GIS environment manages a great amount of data and information. The use of GIS means also allows the development of further geostatistical assessments.Nell’area di studio (hinterland veneziano, Porto Marghera) si segnala la presenza di alcune centinaia di pozzi artesiani (80-350 m di profondità) realizzati nel periodo 1910-1970, successiva-mente dismessi. Tali pozzi rappresentano un possibile passaggio di risalita delle acque artesiane; processo, può innescarsi pertanto un di miscelazione tra le acque sotterranee del Sistema Acquifero Superficiale (0-80 m) con quelle contenute negli acquiferi artesiani profondi (Sistema Acquifero Artesiano, 80-350 m dal piano campagna) dove il potenziale piezometrico è in continua crescita da almeno 40 anni. In tal caso gli acquiferi prossimi al piano campagna (ca 0-30 m) potrebbero essere soggetti alla ricarica attraverso questi pozzi abbandonati. Tale effetto di ricarica va ad aggiungersi ad un sistema idrogeologico fortemente condizionato dalle attività antropiche, quali: il drenaggio prodotto dal sistema di bonifiche costituito da numerose idrovore che mantengono su vaste aree il livello freatico e piezometrico al di sotto del piano campagna; la conterminazione dell’intera area di Porto Marghera, sia in corrispondenza della gronda lagunare, sia nelle aree interne (retromargina-mento). Il marginamento si spinge fino a 15-20 m di profondità.
Tale conterminazione prevede l’allontanamento delle acque sotterranee in surplus, che - attraversando terreni caratterizzati da un forte livello di contaminazione - devono necessariamente essere allontanate e trattate per un opportuno stoccaggio.
La risalita spontanea di flussi di acque sotterranee attraverso pozzi abbandonati a causa di un incremento del potenziale piezometrico negli acquiferi profondi, dal punto di vista scientifico è un argomento poco investigato.
I modelli analitici e numerici disponibili nella letteratura scientifica sono rivolti soprattutto alla definizione di un sistema composto da pozzi profondi dismessi, attraverso si possono avere flussi causati dall’iniezione di rifiuti fluidi o anidride carbonica attraverso da pozzi di re-immissione.
L’applicazione di tali soluzioni richiede la conoscenza di una serie di parametri idrogeologici. Il più importante di questi è la ricostruzione geometrica degli acquiferi coinvolti. Un modello idrogeologico aggiornato dell’intera area di studio risulta essere necessario. Poiché mancano dati di indagini dirette alle profondità di interesse, è stata effettuata una aggiornata ricostruzione idrostrati-grafica dell’unico carotaggio continuo del quale si hanno numerose informazioni: il Ve-1 realizzato a 951 m nel 1971. La successione idrostratigrafica di riferimento ottenuta ha richiesto l’analisi delle più recenti pubblicazioni scientifiche relative al Ve-1 in ambito sedimentologico, palinologico, magnetostratigrafico.
I dati provenienti dalle stratigrafie derivate da alcuni pozzi realizzati a distruzione di nucleo sono stati utilizzati all’interno di un nuovo pacchetto software, sviluppato all’interno del presente studio (modalstrata). Modalstrata consente di ottenere una stratigrafia media da una serie di verticali d’indagine in una determinata area. Nelle aree dove la distribuzione di dati stratigrafici è carente, è stato utilizzato il metodo geofisico della sismica passiva che ha consentito di individuare la conti-nuità laterale di alcuni riflettori principali.
Il modello idrostratigrafico così ottenuto è stato validato attraverso il confronto con la successione idrostratigrafica precedentemente definita per il Ve-1.
This hydrostratigraphic model is confirmed by the comparison of a first hydrostratigraphic series developed for Ve-1.
Il modello idrostratigrafico aggiornato dell’area di studio ha così consentito la definizione delle geometrie da inserire all’interno delle soluzioni analitiche per la definizione delle portate di leakage ad un caso specifico, del quale si dispone di un sufficiente numero di parametri idrogeologici.
Un ambiente GIS gestisce un elevato numero di dati ed informazioni. Il ricorso all’uso di applicativi GIS, permette anche lo sviluppo di ulteriori valutazioni geostatistiche e decisionali
A new hydrostratigraphic model of Venice area (Italy)
No full textTwo environmental problems affect the Venice
area: subsidence, which has been increasing due to the
intensive water abstraction after the Second World War,
and contamination of the soil and shallow aquifers. In order
to address these problems, which are decisive factors in the
entire Venetian ecosystem, the aquifer structure must be
known in detail. The lithologic data are abundant and of
good quality up to a depth of 50 m, whereas boreholes
beyond this depth are much rarer and more dispersed,
making their associated lithological data unreliable. This
work, which uses the available data together with fast and
low cost passive seismic measurements, provides an
improved understanding of the deeper hydrogeologic
domain. For this purpose, a MATLAB package (Modalstrata)
has been developed to improve the correlation of the
stratigraphic succession for each selected homogeneous
sub-area and applied to obtain a new, upgraded hydrostratigraphic
model. The horizontal to vertical spectral ratio
passive seismic surveys have confirmed the lateral correlations
among the sample areas at least for the two main
aquifer horizons. Analysis and comparisons of several
previous studies performed on the data related to the only
drilling continuous coring 951 m deep in the Tronchetto
Island (Venice), have allowed a satisfactory validation of
the proposed hydrogeological model
Laboratory thermal conductivity measurements on gravel sample
Get PDFModern Ground Source Heat Pumps (GSHPs) systems must be designed by taking into account the ground thermal properties, in order to properly plan the capability of the heat pumps to transfer calories through the Ground Source Heat Exchangers (GSHE) to the subsoil (and vice versa). As a result, in order to properly plan the best fitting Heating, Ventilation
and Air Conditioning (HVAC) systems, designers need to couple the energy building loads requirements to the ground thermal properties. Usually, some available information about the geological stratigraphy around the GSHE and soils’ thermal properties bibliography data could provide the preliminary estimation of the main parameters to proper design the GSHP with the related GSHE. On the other hands, alluvial plains and valley floors usually host most of the urban areas and anthropic activities such as cities, commercial districts and industrial region. As a result, for HVAC applications, thermal properties of alluvial materials should be studied more in detail since they have quite a considerable impact on the HVAC efficiency. Gravel thermal properties have been detected by the means of a guarded hot plate Taurus Instruments TLP 800, where some changes in the setup have been made in order
to finalize the thermal measurements
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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