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

The main scope was to provide technological and methodological innovation to the Consorzio di Bonifica Montana del Gargano (CBMG), the land reclamation authority of the Gargano Promontory, to support their responsibilities that ranges from mitigation of hydrogeological risk to water supply, mainly for agricultural purposes. It was pursued by a group of private enterprises, with the CNR-IRPI's Hydrology laboratory support, through the GarganoLab project "Integrated information system for land management, environmental monitoring and emergency alert", funded by the Apulia Region as part of "Living Labs" measures.

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.

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 progressive population growth in coastal areas and the increasing groundwater discharge, together withpeculiarities of karst coastal aquifers constitute a huge worldwide problem, particularly relevant for coastal aquifers ofthe Mediterranean basin (Tulipano et al., 2005).Karst aquifers in coastal regions are well known to be highly vulnerable to the overexploitation of groundwaterresources, both from water increasing demand than from decreasing aquifer recharge due to climate changes. The coastalcarbonate aquifers of the Mediterranean Sea, in particular the Adriatic and Ionian coast that extend between westernGreece and Italy up to the eastern coast of Sicily not only ensure the socio-economic development of the populations butfeeds with spring waters valuable wetland environments with negative effects on ecosystems (Barrocu, 2003; Bonacci,2014; Eftimi & Zojer, 2015; Polemio, 2016).The aim of this study is to develop management and forecast tools to identify the best way to assure enduringavailability of high quality groundwater, and conciliate irrigation and drinking water demands. A geodatabase, collectinginformation for all carbonate aquifers present along the Adriatic and Ionian coast, will be first created. At the core thereis a Geographic Information System, in which are placed the spatial information regarding the geology of aquifers,hydrogeological and geochemical features, together with climatic conditions and specific information concerning past,present and future groundwater usage.The availability of tools that allow the integrated analysis of local hydrogeological situations, in reference to the widerareas where they are located, allows numerous applications. The system, in fact, is not only aimed to archiving, queryingand mapping, but also to operate spatial analysis and the implementation of calculation systems, to return thehydrogeological conceptual models, supporting both the management of groundwater resources and the knowledge forthe protection of coastal environments, and groundwater in general.

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

In karstic areas cases floods are rare, short, and sudden but the effects are often very dramatic. Flash floods (local floods of great volume and short duration, defined by the USA National Weather Service as floods caused by heavy rainfall in a short period of time, generally less than 6 hours) are extremely dangerous. Recent years have seen several flood-related casualties in Italy, in 2003, 2005 (when the last catastrophic flood happened in the karstic area of Bari), and 2007. Flash flood warnings are intrinsically difficult due to the short time available to warn people living next to the river. Our goal in this study was to contribute to the understanding of the relationship between flood events in karstic areas, in terms of recurrence, exceptionality and/or intensity, anthropogenic effects, mainly in terms of population number variations, and damages. Some authors have shown that urbanisation, land use changes, and hydraulics works must be taken into account to really understand the effects of past flood events. A comparative analysis of these data can thus allow us to understand if the trend of flood damage is steady or increasing and to determine whether it is affected by the growing density of population and facilities in flood-prone areas.The approach was based on three types of analyses: the historical analysis, based on historical data, the hydrological and the geomorphological analysis, both based on recent monitored or measured data. The historical analysis was focused on identifying and comparing two kinds of data: the series of past flood events over a period sufficiently wide to define the flood recurrence period and the main steps of anthropogenic development, called the anthropogenic role. This role was expressed using the population number and needs and considering the facilities in flood-prone areas. The hydro-geomorphological analyses were based on two types of data. Long time series of the annual maximum rainfalls of short duration were used to assess the return period of high intensity rainfall that caused studied flood event(s) for which rainfall measurements were available. The geomorphological analysis considered rainfall, hydrogeological characteristics of outcropping rocks and soils, and geomorphological data on the drainage basin to calculate net rainfall and peak flow characteristics. The historical analysis of floods and damages highlighted four flood periods, distinguished on the basis of the recurrence period and the level of damages. The hydro-geomorphological analyses showed the peculiarities of the 2005 flood event. The maximum rainfall return period for the 2005 event was due to exceptional three-hour cumulative rainfall. The study case was a sub-catchment where very high rainfall intensities were observed. The rainfall return period was found to be roughly in the range of 50-100 years, considering a cumulative rainfall duration (3-hour) about equal to the concentration time. This study shows that main modif

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.

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.

To assess the relationships existing between landslide evolution and economical development of a rural, highly prone to landslides, area in southern Italy, a demographic analysis covering the time span from 1861 to 2011 has been performed on about 30 municipalities. The work consisted in a detailed description of the demographic features of the studied area, aimed at analysing the growing/decreasing trend in the local populations, as a function of the main historical and hydrological events. The combined analysis of the above elements with data about landslide distribution and their temporal occurrence allowed to evaluate the influence played by slope instability processes in this sector of Apulia region.

Il Progetto GarganoLab ovvero "Sistema informativo integrato per la gestione del territorio, il monitoraggio ambientale ed allerta di emergenza", finanziato dalla Regione Puglia grazie alle misure "Living Labs", è stato concepito dal consorzio tra le imprese Staer Sistemi, W-Enterprise e Gemict a supporto della domanda di innovazione tecnologica del Consorzio di Bonifica Montana del Gargano (CBMG), al fine di perseguire la riduzione dei rischi idrogeologici e l'ottimale gestione delle opere di mitigazione. La nota descrive il contributo offerto in particolare dal partner di progetto, il Laboratorio di Idrologia del CNR-IRPI. Il progetto ha perseguito la mitigazione dei rischi naturali, dovuti a frane e, soprattutto, piene, e gli effetti della siccità nel territorio del Consorzio di Bonifica Montana del Gargano, con maggiore dettaglio nelle zone più esposte, come il bacino idrografico Molinella di Vieste, drammaticamente interessato anche dal più recente evento alluvionale, occorso nel Gargano dall'1 al 6/9/2014. Il Gargano è un territorio peculiare, spiccatamente montano e carsico; per la forte vicinanza al mare è colpito da fenomeni meteorici particolarmente violenti e repentini; con tali peculiarità il deflusso fluviale è di per se raro, breve e quasi sempre fulmineamente catastrofico. Il contributo del CNR-IRPI è consistito in diverse attività nel seguito brevemente descritte. 1)Analisi statistica delle serie idrologiche e individuazione dei trend: è stato condotto lo studio statistico di tutte le serie storiche climatiche disponibili (dal 1918) per caratterizzare la siccità e l'eccezionalità degli eventi meteorici accaduti o attesi. Ricorrendo ai più opportuni indici statistici, ed in particolare all'indice SPI (Standardized Precipitation Index) maggiormente utilizzato a livello internazionale per descrivere gli eventi estremi della siccità mediante la quantificazione del deficit di precipitazione per diverse scale di tempi o durate, generalmente espressi in mesi, si è così dotato il progetto di uno strumento utile a individuare i trend statistici della siccità per diverse durate temporali, di interesse per gli aspetti meteorologici, idrologici e agricoli. Lo strumento è attivo a ritroso, per molte decine di anni, e si aggiorna in tempo reale, man mano che le misure climatiche si rendono disponibili. 2)Stima delle funzioni di distribuzione della probabilità: le serie dei massimi delle piogge cumulate da un'ora a 5 giorni sono state utilizzate per definire le funzioni di distribuzione della probabilità dei valori estremi a doppia componente (TCEV) a tutti di livelli di regionalizzazione. Tale approccio permette di compensare la limitata estensione del campionamento, ovvero della durata delle misure, limitata rispetto all'obiettivo di stimare tempi di ritorno molto più lunghi delle suddette durate, con le informazioni statisticamente rilevanti presenti nelle serie storiche della medesima regione, attualizzando e affinando i risultati del Proget