The Maltese Islands are located in the central Mediterranean area, on the Malta-Sicily Platform. The archipelago consists of three main islands, Malta, Gozo and Comino, and several small uninhabited islets. Malta, the largest of the three islands, has an extent of 246 km2. The islands present a typical central Mediterranean semi-arid climate with hot dry summers and mild wet winters. The mean-annual rainfall stands at around 550 mm but with high inter- and intra-annual variability. The size of the islands precludes the formation of significant bodies of surface water and therefore the main natural water resources of the islands are the groundwateraquifer systems, in particular the sea-level aquifer systems present in the two larger islands. These aquifer systems are sustained in a carbonate formation (the Lower Coralline Limestone) and take the typical shape of a Ghyben-Herzberg freshwater lens. The high population density of the islands is also reflected in a high level of urban development, where around 25% of the total land area of the islands has been built up. This has altered the physical characteristics of the landscape by significantly increasing the quantity of impermeable surfaces, thereby reducing infiltration processes to groundwater, and increasing the generation of rainwater runoff following rain events. The islands thus present a mixed land-use scenario where domestic, agricultural and commercial activities are operating side by side and depending on the same type of water resources. Of particular reference is the islands' highly developed tourism and recreational sector which places added strain on the water supplies during the dry summer months. Groundwater use for municipal supply is supplemented by the use of sea-water desalination by reverse osmosis. The agricultural sector is mainly dependent on groundwater resources, although water re-use is currently being introduced on a wide scale to supplement (and replace) groundwater use. The use of alternative water resources has thus, in recent years, reduced the pressures on groundwater resources. The aim of this paper is to describe the collaboration between CNR and EWA aimed at the undertaking of a hydrogeological study to support the eventual development of management tools for optimizing the use of Malta's groundwater resources, with specific focus on the main sea-level aquifer system in the island of Malta. As part of this collaboration a review of the hydrogeological environment of the aquifer systems has been undertaken and important data gaps have been identified and are being addressed. The eventual groundwater body. management tool to be developed under this collaborative initiative will enable the formulation and testing of updated groundwater exploitation strategies which ensure the protection of the groundwater bodies from regional and localized sea-water intrusion, whilst taking full consideration of the potential effects of climate change, including the variability o

Carbonate aquifers, located in foreland tectonic settings, could represent important thermal water resources outside the volcanic areas, supplying spas or geothermal installations. Thermal springs constitute the discharge areas of deep marine and continental groundwaters flowing within these carbonate aquifers whose hydraulic conductivity and the relevant geothermal fluid migration are strictly controlled by both the discontinuity network and the karst processes involving the foreland environment. An example of these springs occurs along the south-easternmost portion of the Apulia region (Southern Italy) where some sulphurous and warm waters (22-33 °C) flow out in partially submerged caves located along the coast, thus supplying the spas of Santa Cesarea Terme.These springs are known from ancient times (Aristotele in III century BC) and the physical-chemical features of their thermal waters resulted to be partly influenced by the sea level variations. Some hypotheses about the origin of these warm waters were proposed up to now by previous researches but some uncertainties still exist. For this reason, the area has been selected in order to define the conceptual model of the geothermal resources related to the thermal springs and, as a consequence, the origin of the thermal springs. It is one of the pilot site of the Vigor Project (Evaluation of the geothermal potential of Regions of Convergence), promoted by the Italian Ministry of Economic Development and National Research Council.Santa Cesarea Terme zone is located within the Apulia carbonate platform, the foreland of the southern Apennines, which consists of Jurassic-Cretaceous limestones, thick more than 5 km in the study area and affected by intense karst processes, resting above the Late Triassic evaporite (Burano Fm) and, unconformably, overlaid by Cenozoic calcareous successions. Belonging to a coastal area, the studied groundwater, whose top is located almost to the sea level, is involved in saltwater intrusion and therefore the salt-fresh water interface occurs at some meters below the sea level moving inland. Geological and hydrogeological surveys, including geo-electrical prospecting, and chemical and isotopic analyses of both groundwater and seawater have been carried out. Stable isotopes (?18O, ?D) were used to define the origin of the thermal waters and the recharge mechanism of the geothermal systems while the unstable isotope (3H) was determined for estimating the age of the thermal waters and to define the conceptual model of this low temperature geothermal resource. All the data have been analysed to improve the knowledge of the groundwater flow system, thus assessing the possibility of using low-temperature geothermal fluids to fulfil the thermal needs of the town of Santa Cesarea Terme.In this narrow area, the source of geogenic salinization of spring groundwater was referred to ascending very deep groundwater, more saline than current sea water.The geochemical com

The study discusses the large karstic coastal aquifer of Vlora Bay. This case is peculiar, as the submarine groundwater discharge has a relevant rate of terrestrial inflow in an almost closed bay that is located in an environmentally valuable area.The study is based on four methodological activities: geological and hydrogeological conceptualisation, climatic study and hydrological balance, numerical modelling, and monitoring.A geodatabase was created considering hundreds of data points (wells, springs, rivers, lagoons, and seas) and monthly time series of rainfall, temperature, and river discharge.Monitoring activity was realised over a hydrological year, installing a rainfall network tool and using a network of tens of sampling points, including springs, wells, lagoons and sea. Chemical-physical and stable isotope determinations were realised.Two main groups of aerial springs are fed by the aquifer, one of which is of a coastal type. The total spring discharge is roughly 4 m3/s. The GSD was assessed as being equal to 1.4 m3/s on the basis of the current rate of anthropic discharge and climatic conditions. The study showed the peculiarities of this carbonate coastal aquifer and the importance of its groundwater, which is the chief water source for the third-largest Albanian town. The groundwater quality was generally high, mainly due to the negligible presence of contamination sources on the relief in which the aquifer outcrops. The rate of seawater intrusion effects was also low, thanks to favourable aquifer 3-D geometry and high recharge levels. The increasing anthropic activities constitute a relevant risk in the absence of the introduction of rigorous land and water management criteria.

The Mar Piccolo basin is an internal sea basin located along the Ionian coast (Southern Italy), and it is surrounded primarily by fractured carbonate karstic environment. Because of the karstic features, the main continental water inflow is from groundwater discharge. The Mar Piccolo basin represents a peculiar and sensitive environment and a social emergency because of sea water and sediments pollution. This pollution appears to be caused by the overlapping effects of dangerous anthropogenic activities, including heavy industries and commercial and navy dockyards. The paper aims to define the contribution of subaerial and submarine coastal springs to the hydrological dynamic equilibrium of this internal sea basin. A general approach was defined, including a hydrogeological basin border assessment to detect inflowing springs, detailed geological and hydrogeological conceptualisation, in situ submarine and subaerial spring measurements, and flow numerical modelling. Multiple sources of data were obtained to define a relevant geodatabase, and it contained information on approximately 2,000 wells, located in the study area (1,600 km2). The conceptualisation of the hydrogeological basin, which is 978 km2 wide, was supported by a 3D geological model that interpolated 716 stratigraphic logs. The variability in hydraulic conductivity was determined using hundreds of pumping tests. Five surveys were performed to acquire hydro-geochemical data and spring flow-yield measurements; the isotope groundwater age was assessed and used for model validation. The mean annual volume exchanged by the hydrogeological basin was assessed equal to 106.93 106 m3. The numerical modelling permitted an assessment of the mean monthly yield of each spring outflow (surveyed or not), travel time, and main path flow.

Carbonate aquifers in foreland tectonic settings can host important thermal springs although located inareas commonly not characterized by regional high heat flow values. In these cases, when thermal springsare located close or along the coastlines the subaerial and/or submarine thermal springs constitute theoutflow of marine groundwater, flowing through localized fractures and karsitic rock-volumes. This isthe case of springs occurring along the south-easternmost portion of the Apulia region (Southern Italy)where few sulphurous and warm waters (22-33oC) outflow in partially submerged caves located alongthe shoreline, thus supplying the historical spas of Santa Cesarea Terme. Here, with the aim to define theorigin of the thermal fluids and their deep path, we carried out the geo-structural survey of the area anddetailed hydrogeological and geochemical analyses of the thermal spring fluids. In particular, the isotopes18O, D,13C in DIC,34Ssulphate,34Ssulphide,3He/4He ratio and13C in CO2were used to define the origin ofthe thermal water and the recharge mechanism of the geothermal system while the isotopes3H and14Cwere determined for estimating the age of the thermal waters, resulting in older than roughly twentythousands years BP. The results indicate that the thermal springs are fed by marine water, having reachedSanta Cesarea Terme through a localized fracture network. This affects the evaporitic and carbonatic rocksthat characterize the substratum of the Adriatic Sea in the offshore.

The Mar Piccolo (literally "small sea"), a sea internal basin which is part of the Taranto Gulf, located along theIonian coast in Southern Italy (Apulia region), represents a peculiar and sensitive environmental area and a social emergency due to the pollution of sea water and sediments due to the effect of the neat industrial area of Taranto. Thepaper describes the methodological approach to define the conceptualisation of the hydrogeological basin of main subaerial and submarine coastal springs of the Mar Piccolo. The geochemical discussion concerning spring groundwater was finalised to define the effect of seawater intrusion. These waters are characterised by high values of electrical conductivity and high concentrations of alkaline ions (Na+ and K+) and chloride ion and show typical chemical characteristics of fresh groundwater contaminated by seawater intrusion. The groundwater composition of the subaerial springs of Mar Piccolo is controlled by the combined effects of calcite dissolution and ion exchange. A basicmodel of the coastal aquifer was realised with the purpose to assess the mean annual and monthly value of spring outflows in Mar Piccolo. The computer codes selected for numerical groundwater modelling were MODFLOW and SEAWAT. The active domain of the model was about 978 km2 with a total number of 391200 cells. The researchpursues the knowledge of the hydrological balance of the internal sea, the geochemistry of groundwater, and the groundwater discharge effect on the ecological equilibrium of the coastal environment in the framework of a wide Italian research program called RITMARE.

The data presented in this article are related to the research article described by (Cossu et al., 2018).The data set for this article contains chemical analyses of groundwater and leachate, isotope analysis of groundwater and leachate around a group of landfills located in the municipality of Conversano, close to Bari, the main town of the Apulia Region (Southern Italy). Groundwater samples were collected from eighteen wells.The hydrogeological and chemical study was used to define geochemical features, groundwater and leachate characteristics and to study their potential macroscopic mixing.The land use analysis highlighted quantity and type of used fertilizers permitting to compare these with groundwater in terms of isotopic signature.

The attention of local communities and authorities was focused on the level of groundwater nitrate of a wide coastal karstic aquifer, not far from the town of Bari (southern Italy), worried about the potential effect of sanitary and unsecure landfills. The study considered each potential source of nitrate, considering the type of local land use: mineral fertilizers, septic waste, animal manure and landfill leachate. The hydrochemical investigation was conducted on groundwater of the limestone aquifer and on leachate samples. The most important chemical parameters (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, NO3-) and some minor constituent (Fe, Mn, Hg, As, Zn) are taken into account. In particular the environmental isotopes of hydrogen (H), carbon (C), nitrogen (N) and oxygen (O) were used to identify the groundwater provenance and geochemical reactions. The stable isotopes oxygen-18 (18O) and deuterium (2H) were used to investigate the origin of water in the aquifer system in the study area. The combination of NO3- concentration with ?15N-NO3- and 18O-NO3- in water also provides valuable information for identifying different sources of NO3- to the coastal aquifer. Samples of groundwater and leachate were analysed for 13C and Tritium (3H). Previous studies have demonstrated that the biogeochemical processes within the landfill environment can produce a unique composition for these isotopes, therefore they can be utilized successfully to delineate leachate influence. On-going results are discussed in details for each type of potential source of groundwater quality degradation.

Where the unique natural water resource is groundwater, is the case of wide karstic area, the attention and the susceptibility of local communities and authorities to groundwater risks can be so high to determine relevant misunderstanding due the existence of a number of landfills. For solve this kind of situation, a multi-methodological approach is proposed with the purpose to clarify the role of landfill leakage in terms of groundwater quality degradation risks.The selected study area (SSA) is narrow portion of a wide and deep coastal karstic aquifer, for these characteristics to be considered a case of high complexity and susceptibility. Mainly nitrate and secondly iron groundwater concentration were considered anomalously high in some well of the SSA, not far from Bari (main town of Apulia, a region of Southern Italy), worried about the potential effects of some landfills located in SSA. Five landfills have operated from 1975, one after the other, using increasing safety and technological devices to reduce risks due to leachate leakages with consequent groundwater quality degradation. The multi-methodological approach, which could be potentially applied worldwide, includes: the hydrogeological site characterization; the chemical study and the multi-isotope characterization of groundwater and leachate; the land use analysis and the estimation of nitrogen contributions deriving from agricultural activities, focusing on the use of fertilizers; themineralogical study of groundwater suspended particles to define the origin of some substances, focusing on iron and manganese, relevant for the SSA. The hydrogeological site characterisation highlighted the local peculiarties of the aquifer.The chemical study was focused on the most important chemical features (Ca2+, Mg2+, Na+, K+, Cl-, SO4 2-, NO3-), especially to define geochemical peculiarties, along with some minor chemical elements were taken into account, to define globally the groundwater quality and the leachate characteristics.The environmental isotopes of hydrogen (H), carbon (C), nitrogen (N) and oxygen (O) were used to identify the groundwater provenance and the most relevant geochemical reactions. The oxygen-18 (18O) and deuterium (2H) stable isotopes were used to investigate the origin of water in the aquifer system of the study area. The combination of NO3- concentration with ?15N-NO3-and 18O-NO3- in groundwater also provides valuable information for identifying the true sourcesof anthropoghenic NO3-. Groundwater and leachate samples were analysed for 13C and Tritium(3H), completing the framework of knowledge on the role of leachate on groundwater as previous studies have demonstrated that the biogeochemical processes occurring within the landfill environment can produce a unique composition of these isotopes and therefore they can be utilized successfully to delineate the potential leachate influence. The land use analysis highlighted quantity and type of used fertilizers pe

Geochemical processes occurring at the seawater/freshwater interface were studied for the aquifer feeding the Santa Cesarea thermal springs, located along the coastal sector of the Salento peninsula (southern Italy). Inthis coastal area, seawater is moving into the freshwater carbonate aquifer, pushing so inland beneath the freshwater and creating so an extremely active geochemical environment. In the transition zone, the interaction between the freshwater/saltwater and the aquifer rocks could affect the geochemical composition of the groundwater itself, modifying it even profoundly, as discussed in the paper. The geochemical processes occurring at a seawater/freshwater interface are also described together with the chemical composition of Santa Cesarea thermal springs.

Carbonate aquifers, located in foreland tectonic settings, could represent important thermal water resources outside the volcanic areas, supplying spas or geothermal installations. Thermal springs constitute the discharge areas of deep marine and continental groundwater flowing within these carbonate aquifers whose hydraulic conductivity and the relevant geothermal fluid migration are strictly controlled by both the discontinuity rock network and the karst processes involving the foreland environment. An example of these springs occurs along the south-easternmost portion of the Apulia region (Southern Italy) where some sulphurous and warm waters (22-33 °C) flow out in partially submerged caves located along the coast, thus supplying the spas of Santa Cesarea Terme (referred as SCT in the following). Some hypotheses about the origin of these warm waters were proposed up to now by previous researches but some uncertainties still exist. For this reason, the SCT area was selected in order to define the conceptual model of the geothermal resources related to the thermal springs and, as a consequence, the origin of the thermal springs. This SCT area is one of the pilot site of the Vigor Project (Evaluation of the geothermal potential of Regions of Convergence), promoted by the Italian Ministry of Economic Development and National Research Council. Geological and hydrogeological surveys, including geo-electrical prospecting, and chemical and isotopic analyses of both groundwater and seawater were carried out. Stable isotopes (e.g. ?18O, ?D) were used to define the origin of the thermal waters and the recharge mechanism of the geothermal systems while the radiocarbonate 14C was determined for estimating the age of the thermal waters.All the geological, hydrogeological and geochemical data acquired during the project were so analyzed in order to define the conceptual model of the SCT geothermal resource. The thermal waters arise from ancient seawaters infiltrated at great depth within the seabed substratum, located in front of the Santa Cesarea coastal sector. Moreover allthe data were examined to improve the knowledge of the groundwater flow system, thus assessing the possibility of using low-temperature geothermal fluids to fulfill the thermal needs of the town of Santa Cesarea Terme.

Where the unique natural water resource is groundwater, the attention and the susceptibility of local communities and authorities to groundwater quality degradation risks can be so high to determine relevant problems to waste management, especially for landfills in operation or to be realised. A multi-methodological approach was suggested with the purpose to clarify the role of landfill leakage on groundwater quality degradation.The selected study area (SSA) hosts some landfills in a narrow portion of a wide and deep coastal karstic aquifer, for these characteristics to be considered a case of high hydrogeological complexity and vulnerability. News concerning nitrate and secondly iron groundwater concentration anomalously high caused concern in the population and strong local opposition to landfills.The multi-methodological approach includes: the hydrogeological site characterization; the chemical study and the multi-isotope characterization of groundwater and leachate; the land use analysis and the estimation of nitrogen contributions deriving from fertilizers; the mineralogical study of groundwater suspended particles to define the role of natural soil substances.The hydrogeological site characterisation highlighted the local peculiarities of the aquifer. The chemical study was used to define geochemical features, groundwater and leachate characteristics and their macroscopic mixing.The environmental isotopes of hydrogen, carbon, nitrogen, and oxygen were used to investigate the groundwater origin, the most relevant geochemical reactions, the existence of groundwater-leachate mixing, and the sources of anthropogenic NO3-. The land use analysis highlighted quantity and type of used fertilizers permitting to compare these with groundwater in terms of isotopic signature. The mineralogical study demonstrated the role of suspend natural particles due the presence of terre rosse (red or residual soils) in groundwater.The approach confirmed that there are not the groundwater quality degradation effects of landfills, contributing to reassure population and institutions, simplifying the waste management.

The attention of local communities and authorities was focused on the level of nitrate concentration in ground-water of a wide coastal karstic aquifer, not far from the town of Bari (southern Italy), worried about the poten-tial effect of sanitary and unsecure landfills. Five landfills have operated from 1975, one after the other, using increasing safety and technological devices to reduce risks due to leachate leakages with consequent groundwater quality degradation.A multi-methodological approach was conducted to define the origin of nitrate contamination. The approach includes hydrogeological site characterization, chemical and isotopic study of groundwater and leachate, land use analysis and estimation of nitrogen contributions deriving from agricultural activities, focus-ing on the use of fertilizers and mineralogical study of groundwater suspended particles to define the origin of the iron and manganese in the water samples.In particular, the environmental isotopes of oxygen-18 (18O) and deuterium (2H) were used to investigate the origin of water in the aquifer system of the study area. The combination of NO3- concentration with ?15N-NO3- and 18O-NO3- in water also provides valuable information for identifying different sources of NO3- to the coastal aquifer. Groundwater and leachate samples were analyzed for 13C and Tritium (3H). Previous studies have demonstrated that the biogeochemical processes occurring within the landfill environment can produce a unique composition of these isotopes and therefore they can be utilized successfully to delineate the potential leachate influence.

La prevalente natura carsica del territorio limita la disponibilità di risorse idriche superficiali e conferisce valore particolare alle acque sotterranee della Puglia. Pregevoli per qualità, le acque sotterranee degli acquiferi pugliesi sono state prelevate in misura crescente a partire dai primi decenni del secolo scorso. La crescita dei prelievi ha sottoposto a notevoli "sollecitazioni" il sistema idrogeologico pugliese, dando concretezza ai rischi di degrado sia quantitativo sia qualitativo, rischi tra loro legati nel caso degli acquiferi costieri, quali sono quelli principali pugliesi.L'articolo descrive, con intenzionale brevità, i principali antefatti normativi che hanno regolamentato e regolamentano l'utilizzo delle acque sotterranee pugliesi, ponendo l'attenzione sugli obiettivi che occorre perseguire per coniugare il massimo soddisfacimento della domanda idrica con la duratura tutela di tali preziose risorse naturali e degli equilibri ecologici connessi.Per dare forza agli strumenti di gestione e di controllo e definire chiari obiettivi di tutela è necessario conoscere in modo quantitativo ed accurato quali siano i rischi reali. A questo fine si descrivono brevemente alcuni approcci metodologici accomunati dalla semplicità e dalla ripetibilità delle procedure in contesti non prioritariamente scientifici.L'articolo descrive la variazione della disponibilità della acque sotterranee pugliesi, fondamentalmente discutendo l'andamento dei trend piezometrici e delle portate delle sorgenti (minore attenzione è data al Gargano, per la scarsa disponibilità di dati, e al Tavoliere, per la minore qualità delle acque sotterranee). In sintesi, si osserva una tendenza alla riduzione della disponibilità spiccata ma, per fortuna, non monotona. Tale tendenza è solo in parte giustificabile in relazione alle modificazioni climatiche, che di certo hanno causato un calo della ricarica a partire dagli anni ottanta. Gli effetti più macroscopici riguardano la Murgia e il Tavoliere; rilevanti gli effetti in Salento, in particolare in relazione all'enfatizzazione dei rischi connessi all'intrusione marina.Per la valutazione dell'evoluzione del fenomeno dell'intrusione marina si descrive il criterio a soglia, che persegue l'individuazione del valore di soglia della salinità tra le acque sotterranee dolci e le acque sotterranee contenenti sia pure minime aliquote di acque saline di intrusione marina. Per le acque sotterranee degli acquiferi carbonatici pugliesi detta soglia è risultata pari a circa 0,5 g/l. A partire da tale soglia, si effettua un'analisi spazio-temporale, che permette di individuare le aree soggette a diversa vulnerabilità all'intrusione marina e di discriminare dove i rischi di degrado qualitativo sono più gravi.In ogni caso emerge la drammaticità degli effetti dell'intrusione marina nel Salento e la presenza di estese porzioni del territorio della Murgia e del Salento a rischio di degrado qualitativo per intrusione marina.L'articolo s

The coastal carbonate Apulian aquifers, located in southern Italy, feed numerous coastal cold springs and constitute the main local source of high quality water. The group of Santa Cesarea springs constitutes the unique occurrence of thermal groundwater outflow, observed in partially submerged coastal caves. The spring water is rich of hydrogen sulfide; temperature ranges from 25 to 33 C°. For their properties, spring waters are used for spa activities from several decades. Hydrogeological spring conceptualisations proposed up now were not able to justify water geochemical peculiarities or were not completely confirmed up now. To reduce these uncertainties, a complex hydrogeological survey has been defined. Geological and structural surveys, chemical and isotopic groundwater analyses, spring and well discharge measurements, well loggings, multi-parameters spring automatized measurements, and cave explorations are ongoing. All available data have been used to improve the knowledge of groundwater flow system, including the valuable deep aquifer, the origin of the thermal waters, and to investigate the possibility of using low-enthalpy geothermal fluids to fulfil the thermal needs of the town of Santa Cesarea Terme.

The coastal carbonate Apulian aquifers, located in southern Italy, feed numerous coastal cold springs and constitute the main local source of high quality water. The group of Santa Cesarea springs constitutes the unique occurrence of thermal groundwater outflow, observed in partially submerged coastal caves. The spring water is rich of hydrogen sulfide; temperature ranges from 25 to 33 C°. For their properties, spring waters are used for spa activities from several decades. Hydrogeological spring conceptualisations proposed up now were not able to justify water geochemical peculiarities or were not completely confirmed up now. To reduce these uncertainties, a complex hydrogeological survey has been defined. Geological and structural surveys, chemical and isotopic groundwater analyses, spring and well discharge measurements, well loggings, multi-parameters spring automatized measurements, and cave explorations are ongoing. All available data have been used to improve the knowledge of groundwater flow system, including the valuable deep aquifer, the origin of the thermal waters, and to investigate the possibility of using low-enthalpy geothermal fluids to fulfil the thermal needs of the town of Santa Cesarea Terme.

We investigate a 15.6 km2 landslide-prone catchment in the Apennine Mountains (southern Italy). The catchment is traversed by an 11 km long mid-slope road, which has been damaged by a large number of predominantly shallow landslides. Laboratory tests showed that slope materials, derived predominantly from clay-rich flysch units, have poor geotechnical properties (effective residual friction median values around 11°, effective residual cohesion close to zero). Slope stability analyses were first conducted of representative failed slopes traversed by the road, and for which geotechnical parameters were directly available from the laboratory tests. Site-specific slope stability modelling was carried out following a limit equilibrium method for the determination of a factor of safety. Parametric analysis revealed that the stability of slopes is critically dependent on the groundwater conditions. This is consistent with recurrent episodes of landslide reactivation during particularly wet seasons characterized by periods of high groundwater levels, as documented by in situ monitoring. The evaluation of the site-specific models has enabled extending the slope stability analysis to the full hillslope and wider catchment scales. This was done by exploiting PESERA-L, a freeware software developed to assist in shallow landslide hazard assessment in watersheds. The produced landslide probability maps, fine-tuned and tested using, respectively, the 2006 and 2011 landslide inventories, improve our understanding of differences in susceptibility to slope failure throughout the catchment.

Development of sinkholes in urban and rural area of Apulia (S Italy) is certainly one of the main hazards in the region. Related both to natural and anthropogenic cavities, sinkholes pose serious problems as regards safeguard of the territory, and have recently been the object of interest by mass media and population. For instance, the sinkholes at Marina di Lesina, the Alliste sinkhole in February 2004,the sinkhole of Via Firenze at Gallipoli on March 29, 2007, the several sinkholes in the Altamura municipality.The present work illustrates the research activities carried out by the Basin Authority of Apulia and the Institute of Research for the Hydrogeological Protection (IRPI) of CNR, aimed at predisposing an updated list of the Municipalities of Apulia Region interested by anthropogenic cavities, and at performing detailed studies about development of the underground cavities, and the likely failures induced. The present work, therefore, does not take into consideration sinkholes directly linked to presence of natural caves. An accurate inventory of the anthropogenic cavities in the region has been created, starting from the list by the local caving federation (FSP). The 564 man-made cavities have been analyzed, while detailed historical, archival and bibliographical researches, in turn integrated by interviews with the responsibles of the Technical Offices, were carried out. A survey form has been created to collect and analyze the information on the inventoried cavities; in such form, particular focus was given to those information useful to preliminarly evaluate the susceptibility to failures of the examined sites, also in relation to presence of elements at risk above the cavities, or in their immediate proximity. The first phase of work allowed to obtain a regional framework of knowledge that was useful to select ten municipalities where to perform analysis at a greater detail. These consisted of detailed geological and morphological descriptions, analysis of typology and distribution of the artificial cavities, evaluation of the overall stability in the areas affected by their presence, and description of the engineering works realized in the past, where present. In addition,three specific sites have been individuated to carry out further topographic surveys, and geological-structural analysis as well.All this work allowed to identify those areas in the regional territory that are mostly threatened by likely development of sinkholes related to anthropogenic cavities; further information on about three hundred other cavities have been then found, in many cases being related to systems of cavities rather than to single caves. This also stresses the very high number of man-made cavities in the region (estimated on the order of some thousands), and the need to continue studying sinkholes related to anthropogenic cavities, in order to contribute to mitigation of the related risk.

Hypogenic caves, developed by sulphuric acid speleogenesis, are known all over the world among which the Santa Cesarea Terme caves have been included. They are four submerged caves, located along a coastal carbonate sector in Southern Italy and hosting the outflow of coastal springs of thermal mixed waters (from 21 to 33 °C). These waters derive from the mixing of three water end members: the fresh pure groundwater of a wide karstic aquifer, the deep sulphur thermal water and the seawater. This cave system represents an almost unique case of hypogenic sea caves in carbonate environment. The thermal mixed waters have a different effect on the surrounding rocks of the caves, influencing the sulphuric acid speleogenetic process within the whole cave system. To understand the complex and overlapping natural processes acting on the developmentof these coastal caves, a multidisciplinary study has been carried out. This study has integrated all the data resulting from different methods and technologies, merging morphology, structural geology, hydrogeology, hydrogeochemistry and mineralogy. This multidisciplinary study has allowed to define the main geochemical processes acting within these caves, including the cave development and the formation of the mineral concretions. After the introduction of H2S in the thermal waters, formed by the reduction of sulphates in the sedimentary deposits crossed at depth in the offshore, the oxidation occurs within the caves, producing sulphuric acid. Favoured by upwelling deep-seated thermal flows, this acid dissolves the limestone, with condensation corrosion process that involve replacement of limestone rock with gypsum. This process has resulted to be more active and remarkable within the Gattulla Cave, one of the Santa Cesarea Terme sea caves.

The Mar Piccolo (literally "narrow sea"), a sea internal basin which is part of the Taranto Gulf, located along the Ionian coast in southern Italy (Apulia region), represents both a peculiar and sensitive environmental area and a national environmental and social emergency due to the level of sea water pollution due to the pollutants coming from the close industrial area of Taranto.The area, located between the southern part of the Murgia plateau and the Ionian sea, is geologically characterized by a sequence of Mesozoic limestone (the Apulian carbonate platform) constituting the foreland of the southern Apennines chain. The Mesozoic sequence is intensely fissured and karstified, and forms an important groundwater reservoir.The aquifer occurring in the carbonate sequence of the Murgia plateau feeds numerous coastal springs and constitute the main local source of pure fresh groundwater. Galeso, Battentieri and Riso are the main subaerial springs located along the coast of Mar Piccolo, not far from the town of Taranto. This area is also characterized by several submarine springs, locally called "Citri".Submarine freshwater discharge plays an important, though not well quantified, role in the hydrogeological equilibrium of the system, but also the source of the spreading of many pollutants in the Mar Piccolo area due to the close presence of one of the largest European steel mill together a number of hazardous industrial activities of other types.The paper describes the efforts and the preliminary results to define a detailed conceptualisation of the aquifer as main support to characterise the hydrological balance of the internal sea and the quality of sea water and the effect on of the ecological equilibrium of the coastal environment.

The Cesine Wetland, located along the Adriatic coast, was recognized as a Wetland of International Interest and a National Natural Park. Managed by the "WorldWide Fund for nature" (WWF), it is considered a groundwater dependent ecosystem which is affected by seawater intrusion. The site was selected to test the environmental compatibility of a low-enthalpy geothermal power plant (closed loop) operating in the aquifer saturated portion with purpose to improving the visitor centre. For this purpose, the long-lasting thermal impact on groundwater was assessed using a multi-methodological approach. The complex aquifer system was carefully studied with geological, hydrogeological and geochemical surveys, including chemical and isotopic laboratory analyses of surface water, groundwater and seawater. The isotopes 18O, D, 11B, and 3H were useful to clarify the recharge contribution, the water mixing and the water age. All information was used to improve the conceptualization of the water system, including aquifers and the boundary conditions for a density driven numerical groundwater model. The purpose was to forecast anthropogenic thermal groundwater variations up to 10 years of plant working before the plant realization and to validate the solution after some working years. All results show the environmental compatibility notwithstanding the peculiar ecological environment.