Search

La conoscenza dei flussi energetici scambiati fra oceano e bassa atmosfera è un requisito utile per modellare e comprendere il sistema climatico e la dinamica degli oceani. L’elevata difficoltà di effettuare misure in situ ed in continuo in ambiente marino induce spesso all’utilizzo ausiliario di strumentazione satellitare. Nel presente lavoro è stato effettuato un confronto tra la stima dei flussi energetici superficiali valutati con dati provenienti da satellite e quelli ottenuti da misure in situ. In particolare, per il confronto, sono stati utilizzati i dati SST acquisiti dal satellite NOAA e i dati raccolti in situ dai sensori istallati a bordo della Nave Oceanografica Urania nel corso della Campagna Oceanografica effettuata nel periodo 3 Luglio – 9 Agosto 2005 nel Mediterraneo Centrale. È stata utilizzata la Bulk Formula per stimare i flussi di calore sensibile e latente nelle medesime stazioni di campionamento. Nonostante la risoluzione spaziale dei dati provenienti da satellite permetta di disporre di valori di SST mediati su 1.1 km2 di superficie di mare, i flussi energetici calcolati con le due metodologie mostrano di avere un buon accordo. Il coefficiente di correlazione tra i flussi di calore latente calcolati con i valori di SST acquisiti attraverso i due differenti metodi è 0.91, mentre per i flussi di calore sensibile è 0.94.

This study examined the effects of recorded boat noises on the behaviour and biochemistry of the common prawn ( Palaemon serratus ) in laboratory settings. The experiment was carried out in a tank equipped with a video-recording system using six groups (three control and three tested) of eight common prawns (48 animals in total). After habituation for 1 h, the behaviour of the prawns was monitored for 1 h. During the last 30 min, the animals in the test groups were exposed to noise resembling a marine area with high anthropogenic acoustic pollution. The exposure to noise produced significant changes in locomotor patterns, presence inside or outside a shelter, total protein concentrations in the haemolymph and brain, DNA integrity, and the expression protein levels of HSP 27 and 70 in brain tissues, revealing a stressful effect of noise on this crustacean species. This study clearly reveals that invertebrates are likely to be susceptible to acoustic stimuli from boat's noise and that they are potential valuable targets for further and detailed investigations into the effects of the anthropogenic noise pollution.

Landfilling should be the last option in an integrated Municipal Solid Waste (MSW) management approach. In the European Union (EU), the policy framework to protect the environment and the public health against the impact of health hazards related to urban solid waste management has been consistently implemented in recent decades. A growing interest in the negative impact of fires in waste landfills on the environment and people’s health was reported in some European countries. In Italy, an increasing occurrence of arsons in MSW and landfills has been reported in recent years. During the summer of 2012, a multi-site arson occurred in the Palermo Municipal solid waste landfill of Bellolampo (western Sicily), giving rise to an environmental emergency of public health concern. Local health authorities reacted by creating an inter-institutional multidisciplinary task force with the aim to implement measures to prevent and control the risk of exposure by delimiting a protection area to be taken under strict monitoring. Environmental and epidemiological investigations were put in place by air, soil, and farm product sampling. A syndromic surveillance of the exposed population was conducted as well. The air monitoring stations system in place detected an increase in the concentrations of dioxins and dioxin-like substances with the PM10 highest emission pick documented within the first 24 h and estimated at about 60 μg/m3. Levels of heavy metals above the limits permitted by law were detected in the top- and sub-soil samples collected within the two landfill sampling sites and also in other nearby sites. Non-conforming concentration values of dioxins and dioxin-like substances were detected in samples taken from farms, milk, and water. The health syndromic surveillance did not document any daily increase in the notification of emergency admissions related to acute respiratory diseases or any other health effect potentially related to the waste arson, but these findings were limited by the non-systematic collection of data. The experience reported in the present case report, as declined within the European Union policy framework and in the view of environmental justice, documented the need to structure a permanent collaboration between the different institutional actors involved in environmental and public health protection activities in order to develop specific protocols to manage events related to the occurrence of waste-related environmental emergencies or disasters.

In this study, underwater noise from a full-scale wave energy converter system (ISWEC), installed on the coast of Pantelleria Island (central Mediterranean Sea), was characterized. The noise was measured using an autonomous acoustic recorder anchored to the sea bottom 40 m from the ISWEC hull. Acoustic monitoring continued for 15 months, starting 7 months before (PRE), 2 months during (INST) and 6 months after the ISWEC installation (POST). The levels of noise, assessed with power spectrum density and octave and third-octave band sound pressure levels (BSPLs), were higher during the POST period than during the PRE period at lower frequencies up to 4 kHz and increased with wave height. During the ISWEC activation for energy production (POST_ON) in the wave height range 1–2.9 m, the BSPLs increased much more at lower frequencies up to 4 kHz (the median BSPLs at 63 Hz for the PRE, POST, and POST_ON conditions were 73, 106, and 126 dB re 1μPa, respectively). Considering the biophonies that make up the soundscape of the area, we examined the possible masking of fish choruses due to ISWEC noise and highlighted that at a distance of 1000 m, the 800 Hz peak frequency was 10 dB above the ISWEC signal. Within this distance from ISWEC, a possible masking effect is supposed.

We study and implement a simple method, based on the Perfectly Matched Layer approach, to treat non reflecting boundary conditions with the Smoothed Particles Hydrodynamics numerical algorithm. The method is based on the concept of physical damping operating on a fictitious layer added to the computational domain. The method works for both 1D and 2D cases, but here we illustrate it in the case of 1D and 2D time dependent shallow waves propagating in a finite domain.

We focus on the study and implementation of Smoothed Particle Hydrodynamics (SPH) numerical code to deal with non-reflecting boundary conditions, starting from the Perfect Matched Layer (PML) approach. Basically, the method exploits the concept of a physical damping which acts on a fictitious layer added to the edges of computational domain. In this paper, we develop the study of time dependent shallow waves propagating on a finite 2D-XY plane domain and their behavior in the presence of circular and, more generic, rectangular boundary absorbing layers. In particular, an analysis of variation of the layer׳s thickness versus the absorbing efficiency is conducted. In our model, the magnitude of absorbtion of a specific layer in which two types of damping functions (linear and hyperbolic) are activated is compared with the one produced by the antithetical cases of total reflecting and open boundaries. The results obtained indicate the good applicability of PML approach to SPH numerical scheme showing high absorption values with reasonable thickness of the absorbing layers.

It is generally acknowledged that vulnerability mapping represents an essential tool for territory management. Intrinsic vulnerability can be generally described as “the susceptibility of the aquifer systems, in their different components and in different geometric and hydrodynamics situations, to swallow and diffuse, also mitigating the effects, a fluid or water-transported pollutant, in such a way to produce impact on the groundwater quality, in space and time”. Assessment procedures of vulnerability consider a number of parameters, the estimation of which is usually difficult and very often insufficient to correctly represent aquifer’s features. As aquifers are closely influenced by numerous factors, their behavior is difficult to be predicted. For example, the most common methods to evaluate vulnerability, like SINTACS, assign scores and weights to a number of parameters, mainly depending on granulometric and textural properties, the estimation of which is frequently arduous and sometimes inadequate to perform reliable and accurate models of water systems. This paper shows the first results of a study about the expected correlation among selected maps of SINTACS system. They belong to the original set of seven parameters, utilized to perform a vulnerability cartography for a generic zone. Several SINTACS applications have been realized on sites of Italian Peninsula characterized by meaningful social-economic importance. Advanced modifications to the available standard are producing new protocols more appropriate for the surveyed areas. The aim was to validate the hypothesis to obtain similar information as respect to the original method by using just a selection of the seven maps. In order to assess this potential correlation resulting in superfluous information, a full statistical analysis has been performed on data from some urbanized areas of Sicily - namely Carini, Acquedolci and S. Agata di Militello - and results are reported in the present work. More specifically, Pearson's linear correlation coefficient matrixes have been computed and analyzed for each different couple of variables, maps being shifted both horizontally and vertically. In order to determine boundary values of those parameters indicating a similarity grade between a couple of identical maps, the correlation coefficient trend has been also investigated among the mentioned couple of maps, again shifted both horizontally and vertically. It results that in the analyzed data the investigated correlation actually exists. This strongly suggests to develop adjustments to the available standards, trying to create new protocols more adherent to the particular sites under investigation. In this particular case, for example, a considerable refinement of the SINTACS approach could be achieved using just five parameters instead of seven. In fact, it results that the map giving the vulnerability indexes - obtained after such parameters reduction - is statistically equivalent to that resulting through the original SINTACS approach. Software utilized in the shown procedure has been implemented in Matlab® environment. The numerical approaches have methodically permitted to realize a severe selection and reduction of parameters and to outline - in certain Sicily areas - the real importance of selected SINTACS factors, clearly influencing the transport processes of contaminants towards the aquifer. As a matter of fact, the investigated aquifers can be defined as complex ecological systems, their depiction seeming likely to be closely conditioned by a number of geometrical and hydrogeological parameters, which rarely portray the real hydrogeological behavior of the underground systems. Authors show how the statistical elaboration, applied to vulnerability settings, can contribute to an implementation of the hydrogeological passive scenery offered by complex aquifers as the considered ones.