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This study improves knowledge on the hydrogeology of Ischia Island, an active volcano of southern Italy. Combining previous published and unpublished data with newly collected data, and through the results of simplified numerical models, the existing conceptual hydrogeological model of the volcanic island has been reviewed and the present impact of intensive withdrawals on the island’s groundwater resources has been examined. Two areas with different hydrogeological characteristics have been recognized: (1) the resurgent block of Mt. Epomeo, where an independent and uplifted basal groundwater circulation exists; (2) the external areas of Mt. Epomeo, where a continuous basal aquifer and local discontinuous perched aquifers have been distinguished. The marginal faults of the resurgent block of Mt. Epomeo represent the preferential pathways of ascending deep fluids. In natural conditions, the island’s aquifers are recharged by rainfall and by deep fluids from beneath, discharging towards the sea and the springs. Since the start of activity at the spa facilities, involving intensive pumping from wells, a further and significant recharge of the aquifers has come from seawater and from increased upwelling of the deep fluids. Although this does not compromise the sustainability of the groundwater withdrawals in quantitative terms, the pumping rates determine the quality of the water captured by the wells. The great variability in temperature and chemical composition of groundwater of the island is also influenced by local hydrogeological parameters and characteristics of the wells from which the water samples were taken, as well as the phenomena of interaction among different end-members.

Conventional hydrogeological practice is to formulate a conceptual model, which is often the basis of a numerical model. The numerical model is then used to test groundwater management strategies. A workflow is proposed, employing the numerically enhanced conceptual model (NECoM) of the Mean Sea Level Aquifer (MSLA) on the island of Malta. The Malta MSLA is overexploited and under threat of salinization. Data (heads, chloride concentrations, electrical conductivity logs, tidal tests and qualitative analyses) were assimilated into a fast-running numerical model. Simultaneously, strategies for optimal acquisition of further data were examined through the modelling process. The model was delivered through the Energy and Water Agency, with suggestions for flexible model deployment. These workflows will, hopefully, spawn model improvements through further revision of the base concepts. The model allows the agency to make predictions, which have uncertainties that are quantified and reduced through data assimilation as new data become available. Contemplated management plans can therefore be properly assessed before implementation. The proposed NECoM approach can be generalized since it bases model usage on the premise that modelling should make maximum use of existing data by assimilating its information content, thereby highlighting the uncertainties of decision-critical predictions that remain because of data insufficiency. Thus, the presently disjointed process of modelling on the one hand, and data acquisition on the other, can be better aligned. Conceptual and numerical model development become parallel, rather than sequential, activities. Together, they enable predictions of future system behaviour for which bias is reduced and uncertainties quantified.

Geological and hydrogeological conceptualizations of the five main aquifers of Malta were performed by means of characterization of the groundwater bodies’ geometries to assess their hydraulic properties. The starting point was 23 new geological cross-sections, intended to intercept all the main structural features of the Maltese archipelago at once. This conceptual analysis constitutes a fundamental phase in the development of groundwater models, and in turn influences the assessment of transmissivity and the numerical models’ structure, calibration and related uncertainties. Besides the construction of the geological sections, a crucial step in building a coherent geological conceptual model involved data homogenization and use of different tuning scales, with respect to both geometric and hydraulic aquifer features. Cross-section quality was spatially assessed by the fit on both a high-resolution digital terrain model and the surface geological data, and the information was subsequently merged with previously determined inconsistencies within borehole stratigraphic data collected from various sources. The geological boundaries data (contact lines and point data) and the dense fault system of the Maltese islands (horst and graben structure) were interpolated by means of the “spline with barriers” algorithm. The resulting surfaces of the main geological formation beds constitute the new detailed geological conceptual model of the whole Maltese archipelago, needed for a more reliable assessment of hydrogeological parameters. The achieved hydrogeological conceptual models of the main Maltese groundwater bodies constitute the basis for groundwater numerical modelling to better understand and quantify the groundwater resources available within the hydrological reservoirs.

The thermal waters of the Island of Ischia, an active volcano located in Southern Italy, are widely used for supplying numerous spas. Groundwater withdrawals occur mainly through wells in the coastal strip. This study explores the impact of withdrawals on the quality of the waters used in thermal facilities, which is required to be constant in terms of composition and temperature by law. For this purpose, specific investigations were conducted including 155 pumping tests, 124 water temperature measurements during pumping tests, 31 temperature and electrical conductivity logs and periodic chemical analysis of the waters of 21 selected wells. By comparing the response to pumping of the aquifer and the quality of the water extracted from the wells, it turned out that the quality of groundwater supplying spas depends not only on natural phenomena (meteoric recharge, seawater intrusion, and rising of deep hydrothermal fluids) but also relies on the island sector where groundwater is pumped and on the pumping method. The distance of the wells from the coast, the type of aquifer formation intersected by the wells, and the field of groundwater temperature of the hydrothermal system strongly affect the aquifer pumping response, determining the quality of water extracted from wells and its variation over time. In Ischia, techniques and regimes of groundwater withdrawals should adapt to the local aquifer pumping response, more than in another hydrogeological context. The concomitant analysis of drawdown, water temperature, and salinity during pumping turned out to be a valuable tool to define the sustainable yield of the single well.

Bioremediation is an active process for the detoxification of polluted ambient media employing the metabolism of microbes, while natural attenuation relies on physical, chemical and biological processes occurring without human intervention. A shallow aquifer (A0) was treated using a bioremediation approach through the amendment of whey to detoxify the most abundant contaminants: 1,1,2,2- tetrachloroethane (1,1,2,2-TeCA), perchloroethene (PCE) and trichloroethene (TCE). A deeper aquifer (A1), showing lower concentration of the contaminants, was left untreated. In A0, a concomitant decrease of more chlorinated molecules 1,1,2,2-TeCA, PCE and TCE and an increase of less halogenated molecules such as trichloroethane (1,1,2-TCA), cis-dichloroethene (cis-DCE) and vinyl chloride (VC) were observed, suggesting that a reductive dechlorination took place. In contrast, the aquifer A1 did not show a significant decrease of contaminants during this period. A metagenomic approach (shot gun and 16S rRNA gene) was then used to investigate the microbial population of the two aquifers. A massive presence of the dehalogenator Dehalococcoides mccartyi (D. mccartyi) and a spectrum of different Geobacter species were detected in A0, after the treatment. The metagenome assembly of shotgun (SG) data further indicated a significant presence of methanogenic archaea, most likely from class Methanomassiliicoccales, at a level comparable to that of D. mccartyi. Instead, A1 was characterized by the species Burkholderia, Curvibacter and Flavobacterium. These results indicate that the autochthonous microbial consortia reflected the geochemistry of the two aquifers, with a dominant population thriving in an anoxic and nutrient rich environment implicated in reductive dehalogenation in A0 and a more diverse population, not able to decompose the pollutants, in A1.

How do political connections affect firm dynamics, innovation, and creative destruction? We extend a Schumpeterian growth model with political connections that help firms ease bureaucratic and regulatory burden. The model highlights how political connections influence an economy’s business dynamism and innovation, and generates a number of implications guiding our empirical analysis. We construct a new large-scale data set for the period 1993–2014, on the universe of firms, workers, and politicians, complemented with corporate financial statements, patent data, and election data, so as to define connected firms as those employing local politicians. We identify a leadership paradox: market leaders are much more likely to be politically connected, but much less likely to innovate. Political connections relate to a higher rate of survival, as well as growth in employment and revenues, but not in productivity—a result that we also confirm using the regression discontinuity design. At the aggregate level, gains from political connections do not offset losses stemming from lower reallocation and growth.

Innovation in SMEs exhibits some peculiar features that most traditional indicators of innovation activity do not capture. Therefore, in this paper, we develop a structural model of innovation that incorporates information on innovation success from firm surveys along with the usual R & amp;D expenditures and productivity measures. We then apply the model to data on Italian SMEs from the \"Survey on Manufacturing Firms\" conducted by Mediocredito-Capitalia covering the period 1995-2003. The model is estimated in steps, following the logic of firms' decisions and outcomes. We find that international competition fosters R & amp;D intensity, especially for high-tech firms. Firm size and R & amp;D intensity, along with investment in equipment, enhances the likelihood of having both process and product innovation. Both these kinds of innovation have a positive impact on firm's productivity, especially process innovation. Among SMEs, larger and older firms seem to be less productive.

Two small Maltese aquifers, Mizieb and Pwales, were numerically analyzed to test the existing hydrogeological conceptual model and suggest optimized groundwater monitoring strategies in support of the forthcoming monitoring network coordinated by the Government of Malta through the Energy and Water Agency. The model will undergo further revision of the concepts on which it is based as soon as new data is available, considering the conceptual and numerical model development as parallel activities, rather than as sequential. The model structure and parameter estimation made use of qualitative information and data acquired by archive research; during model calibration information/assumptions were introduced as “prior information” while the available measurements were introduced as classical “observations” with proper associated weight. The information content of both qualitative and quantitative data could be assimilated along the calibration process, highlighting the uncertainties and open questions that remain because of data insufficiency.

Crystalline rocks constitute aquifers that are of interest for water supply in many countries. In Italy, the hydrogeological characteristics of crystalline rocks are not well known and the interest in these aquifers is generally scarce. Nevertheless, the large extent of these rocks in Sardinia and Calabria regions and the local scarcity of water resources justify this preliminary analysis. Crossing the information derived by the available data on climate conditions, type of crystalline rock, structural setting, characteristics of wells and springs, base flow of streams and rivers and pumping test results, a preliminary quantification of the potential yield of the crystalline aquifers of both regions was performed. The processing of data involving different aspects confirmed that the crystalline rocks of Sardinia and Calabria form low-permeability aquifers where groundwater circulation occurs in the weathered layer and, mainly, in the most fissured layers closest to the surface. In the heavily fractured zones, it was seen that the groundwater flow is more active and can also occur at a greater depth. Groundwater mainly outflows in the valleys, feeding streams, numerous low discharge springs and surrounding aquifers. Climate, rock covers and tectonic style influence the aquifer yield, which has been evaluated herein to range from 1 to 2 L/s per km2 and from 2 to 12 L/s per km2 in Sardinia and Calabria, respectively. This preliminary characterization shows that there are reasons to deepen the present knowledge on these aquifers in order to optimize the present use of their groundwater resources