Le acque del Carso classico : Progetto Hydrokarst

Dopo quasi 200 anni dalle prime ricerche sul Timavo, prende il via il Progetto HYDROKARST nato dalle idee di ricercatori italiani e sloveni che da anni studiano insieme l\u2019idrogeologia carsica (www.hydrokarstproject.eu). Il progetto ha come obiettivo la gestione coordinata e la tutela dell\u2019acquifero transfrontaliero del Reka-Timavo attraverso l\u2019istituzionalizzazione di una rete di monitoraggio quantitativo e qualitativo delle acque ipogee e del territorio del Carso Classico. Il progetto si propone di garantire, attraverso delle partnership stabili, una gestione sostenibile della risorsa acqua rafforzando quella coesione territoriale transfrontaliera che deve portare alla redazione di protocolli congiunti per permettere di uniformare le metodologie di raccolta dati e la loro rappresentazione e codifica, primo passo per la definizione delle aree di salvaguardia delle sorgenti e dei pozzi captati a scopo idropotabile. Va ricordato che ad oggi, le acque del Reka-Timavo non sono legalmente tutelate, cosa che invece accade per quelle del fiume Isonzo-So\u10da. Il progetto \ue8 suddiviso in sette diversi Workpakages (WP). WP1: Progettazione e costruzione del quadro logico per la gestione del progetto. Monitoraggio coordinamento e rendicontazioni. WP2: Ideazione, preparazione e definizione dell\u2019idea progettuale. WP3: Raccolta ed elaborazione dei dati idrodinamici, idrochimici e biologici dell\u2019acquifero del Reka-Timavo. WP4: Vulnerabilit\ue0 degli acquiferi carsici e protocolli di individuazione delle aree di salvaguardia. Uso del suolo. Analisi della stabilit\ue0 della rete di distribuzione e delle necessit\ue0 di approvvigionamento idrico. WP5: Elaborazione della cartografia unificata del Carso Classico. WP6: Elaborazione di protocolli per la gestione condivisa delle risorse e delle riserve acquifere del Carso Classico. WP7: Piano di comunicazione. La fase di condivisione dati ha portato alla realizzazione di una base cartografica unificata e di una banca dati georeferenziata (GIS) di tutto il bacino del Carso Classico. Attraverso la raccolta dati prima, e l\u2019elaborazione poi, si \ue8 giunti alla definizione di un modello concettuale dell\u2019intero acquifero del Reka-Timavo. Buona parte di questi dati hanno successivamente permesso l\u2019elaborazione delle carte di vulnerabilit\ue0, a loro volta determinanti per la delimitazione delle aree di salvaguardia. Il monitoraggio della rete acquedottistica di distribuzione e la realizzazione di interventi per il risparmio idrico hanno permesso di promuovere progetti di minimizzazione delle perdite, ottimizzando tratti poco efficienti delle reti. Scopo ultimo del progetto era pertanto l\u2019elaborazione: \u2013 di accordi di cooperazione e di azioni per la promozione ed attuazione di sistemi per la riduzione delle emissioni inquinanti con particolare riferimento all\u2019acqua potabile; \u2013 di sistemi di intervento congiunti nelle situazioni di emergenza; \u2013 di strategie congiunte per prevenire e ridurre i rischi; \u2013 di interventi per il risparmio idrico, l\u2019efficienza nella gestione della rete idrica ed il miglioramento della qualit\ue0 dell\u2019acqua potabile. Skoraj dvesto let po prvih raziskavah reke Timave so italijanski in slovenski raziskovalci, ki \u17ee ve\u10d let skupaj preu\u10dujejo kra\u161ko hidrogeologijo, oblikovali Projekt HYDROKARST (www.hydrokarst-project.eu). Cilj projekta je koordinirano upravljanje in za\u161\u10dita \u10dezmejnega vodonosnika Reka-Timava z institucionalizacijo omre\u17eja za koli\u10dinsko in kakovostno spremljanje podzemnih voda na obmo\u10dju klasi\u10dnega Krasa. Namen projekta je, da se z vzpostavitvijo stalnega partnerstva zagotovi trajnostno upravljanje vodnega vira, \u10dezmejna teritorialna kohezija in priprava skupnih strokovnih podlag, ki bodo omogo\u10dale poenotenje metodologij zbiranja, prikazovanja in kodifikacije podatkov, kar je prvi korak v smeri definicije za\u161\u10ditenih obmo\u10dij izvirov in zajemali\u161\u10d pitne vode. Naj spomnimo, da vse do dana\u161njih dni vodonosnik Reka-Timava ni bil dele\u17een nikakr\u161ne pravne za\u161\u10dite \u2013 v nasprotju na primer s So\u10do (Isonzo). Projekt sestavlja sedem razli\u10dnih delovnih sklopov (WP): WP1: Oblikovanje \u201cstoritvenega sistema\u201d in priprava logi\u10dnega okvira za upravljanje projekta. Spremljanje projekta, koordiniranje in finan\u10dno poro\u10danje. WP2: Oblikovanje, priprava in dolo\u10ditev projektne ideje. WP3: Meritve in obdelava hidrodinami\u10dnih podatkov vodonosnika Reka-Timava. WP4: Ranljivost kra\u161kih vodonosnikov in protokoli za dolo\u10ditev vodovarstvenih obmo\u10dij. Raba tal. Analiza stabilnosti distribucijskegaomre\u17eja in potreb po vodni preskrbi. WP5: Priprava skupnih kartografskih prikazov mati\u10dnega Krasa. WP6: Priprava protokolov za skupno upravljanje virov in zalog mati\u10dnega Krasa. WP7: Komunikacijska kampanja o razvoju projekta in dose\u17eenih ciljih. Faza izmenjave podatkov je omogo\u10dila vzpostavitev enotnih kartografskih podlag in enotne georeferencirane podatkovne baze (GIS) za celotno obmo\u10dje mati\u10dnega Krasa. Z zbiranjem in obdelavo podatkov smo izdelali konceptualni model celotnega vodonosnika Reka-Timava. Ti podatki so nadalje omogo\u10dili izdelavo kart ranljivosti, ki so bistvenega pomena za dolo\u10ditev vodovarstvenih obmo\u10dij. Spremljanje distribucijskega vodovodnega omre\u17eja in izvajanje ukrepov za var\u10devanje z vodo je omogo\u10dilo implementacijo projektov za zmanj\u161anje izgub z izbolj\u161avami na neu\u10dinkovitih delih omre\u17eja. Kon\u10dni cilj projekta je torej: \u2013 sklenitev protokolov o sodelovanju in dolo\u10ditev ukrepov promocije in uresni\u10denja sistemov za zmanj\u161anje onesna\u17eevalnih emisij, predvsem tistih, ki se nana\u161ajo na pitno vodo; \u2013 razvoj sistemov skupnega poseganja v nujnih primerih; \u2013 oblikovanje skupnih strategij za prepre\u10devanje in zmanj\u161evanje tveganj; \u2013 promocija posegov za var\u10devanje z vodo, u\u10dinkovito upravljanje vodovodnega omre\u17eja in izbolj\u161anje kakovosti pitne vode

Flood Hazard in the Classical Karst: The Case of Mucille Polje (NE Italy)

In the north-western area of the Classical Karst (NE Italy), the Mucille depression, after abundant precipitations, is subject to frequent floodings, which become problematic since 2001 as they more frequently affect housing and recreational areas, leading the population to believe that the swallow holes draining the area stopped functioning. The climate changes as well as the increased frequency of intense rainfall events led to evaluate the draining capacity of the swallow holes in order to provide fundamentals for the mitigation measures. The depression is fed by a spring area and drained by two swallow holes one of which is permanently active, while the other functions only during floods. About 24 h after the onset of heavy rains, the whole depressed area is flooded. About 8 days later, the water level begins to decrease, coming back to its initial height in about fifteen days. During floods, while springs and swallow holes discharges measurements are impossible, the extension of the flooded areas has been mapped. The obtained flooded surface together with high resolution DTM coverage allows to calculate the volume of surface water. Consequently, the hydrologic balance can be estimated during the whole event. This study provides meaningful evidences for the design of measures to mitigate the risk. It estimates the discharge of the swallow holes, confirming their efficiency. Nonetheless, it also emphasizes the need to improve their draining capacity, especially considering the unsuspected high outflow of the springs at the onset of the flood

Gypsum Dissolution Rate, New Data and Insights

Sinkholes linked to covered evaporite karst in urban environments still represent a challenge in hazard and risk assessment. The Quinis hamlet, located in Friuli Venezia Giulia region (NE Italy), is heavily affected by sinkhole phenomena (linked to an evaporitic bedrock), which deeply interested infrastructures and houses. In order to understand the evolution of the sinking phenomena, a field experiment started on the dissolution rate of the gypsum. In 17 existing piezometers, at different depths, 51 evaporitic rock samples were exposed to the naturally occurring variation of relative humidity, air flow and hydrodynamics. The rock samples were placed respectively in the aeration, in the fluctuation and in the phreatic section of the piezometric tubes. Data related to groundwater level fluctuations, temperature and electrical conductivity were collected. After four months, rock samples were removed, weighted and the volume loss evaluated. The obtained results indicate that rock sample reduction is not only dependent on the groundwater level fluctuations and on the number of days during which the samples are immersed in the groundwaters but also on the mineralization of the latter. Some of the rock samples have been almost completely dissolved, with dissolution rate values almost eight times bigger than expected if compared to the available literature data. The proposed approach had as aim to evaluate the quickness of the dissolution process, which is dependant on several causes (groundwater level fluctuations, type of rocks, chemical characteristics of the groundwaters, etc.) and represents a novel contribution to the overall knowledge of karst processes with noticeable impacts on human-built construction

Classical Karst hydrodynamics: a shared aquifer within Italy and Slovenia

Abstract. The classical Karst transboundary aquifer is a limestone plateau of 750 km2 that extends from Brkini hills in Slovenia to Isonzo River in Italy. For 20 years, and especially in the last two years, the Mathematic and Geosciences Department of Trieste University has run a monitoring project in order to better understand the groundwater hydrodynamics and the relation between the fracture and conduit systems. A total of 14 water points, including caves, springs and piezometers are monitored and temperature, water level and EC data are recorded. Two sectors are highlighted: the southeastern sector mainly influenced by the sinking of the Reka River, and a northwestern sector connected to the influent character of the Isonzo River. Water table fluctuations are significant, with risings of > 100 m. During floods most of the circuits are under pressure, and only a comparative analysis of water levels, temperature and EC permits a precise evaluation of the water transit times in fractured and/or karstified volumes

Flood hazard assessment in a polje: the case of Mucille (Classical Karst Region, NE Italy).

The Mucille karst depression is one of the few examples of polje on the Italian side of the Classical Karst Region, a shared area between Italy and Slovenia. The polje is subject to frequent flooding, becoming more problematic since 2000, as swallow holes more frequently have affected housing and recreational areas, leading the population to believe that their ability in draining the area had stopped functioning. Climate changes play an important role as there has been an intensification in extreme events (30-day cumulative precipitation of more than 350 mm) within the considered time-period 1919–2020. The necessity to provide answers to the inhabitants required in-depth studies such as hydrogeological investigations, discharge measurements and Electrical Resistivity Tomography (ERT) acquisitions. Over the 3 years of monitoring (2017–2020), two flood events reached the Selz settlement. In total, four events have been analysed to build a hydrogeological model of the area in order to properly estimate its recharge and regression curve, and to define the functionalities of the swallow holes. The defined model allowed a better knowledge and a greater awareness in proposing the proper mitigation measures able to increase the drainage capacity of the area avoiding always more frequent future floodings

Rheological investigation and simulation of a debris-flow event in the Fella watershed

Abstract. To set an approach for the future territorial planning, the Geological Survey of Friuli Venezia Giulia Region, through the researchers of Trieste University, started a program of debris-flow risk analysis using Flo-2D software as tool to delimit the hazardous areas. In the present paper, as a case study, a debris flow, called Fella sx, occurring in a torrent catchment was analyzed. The choice was due to the abundance of information about past events, inundated areas, rain fall, geology and to its representativeness. An initial back-analysis investigation identified a couple of representative rheological parameters. Riverbed samples were collected, sieve analyses were performed and rheological tests were carried out on the fraction finer than 0.063 mm using a rotationally controlled stress rehometer equipped with the serrated parallel plate geometry. The shear dependent behaviour was examined at different concentrations ranging from 33 to 48%, by weight. Viscosity data treatment was performed to determine the most suitable rheological model to provide the best approximation of the debris-flow behaviour. The rheological parameters, derived from experimental data, were used and compared with those obtained through the back-analysis and with the real inundated area. Data obtained through rheological analysis are useful in constructing scenarios of future events where no data for back-analysis are available

Anthropometric comparison between young Estonian and Chinese swimmers

Due to the progressive lowering of the age of peak performance among swimmers, it became important to better understand the factors influencing performance in prepuberal boys and girls. Aim of this study is to compare two different racial/ethnic groups of young swimmers, one from Nord-Europe, Estonia (Tartuma Region), and the other from China (Shanghai District) in order to assess existing differences in respect to body dimension, body fat, technical parameters of swimming performance and maximum lactate production. 26 Estonian and 7 Chinese female and 25 Estonian and 10 Chinese male, from two swimming schools, took part in the study. Anthropometric parameters were measured in accord with ISAK guidelines. BMI, Stroke Index, Stroke Length, mean velocity on a 200 m freestyle all out, and blood lactate after three minutes were measured. Significant differences exist in anthropometry between Nord-European and Asian young swimmers. These differences are more pronounced in female, with higher fat tissue in Nordic girls. Leg lengths are different between Chinese and Estonian girls having the Estonian longer legs. Hands lengths are different both in male and in female subjects. Being the Chinese groups of higher level of performance (higher mean velocity in the 200 m freestyle, such differences seems not to be as major determinants of the performance, also if they are often indicated as determinants of buoyancy and stroke efficiency

Non-invasive methodological approach to detect and characterize high-risk sinkholes in urban cover evaporite karst: Integrated reflection seismics, PS-INSAR, leveling, 3D-GPR and ancillary data. a Ne Italian case study

Sinkholes linked to cover evaporite karst in urban environments still represent a challenge in terms of their clear identification and mapping considering the rehash and man-made structures. In the present research, we have proposed and tested a methodology to identify the subsiding features through an integrated and non-invasive multi-scale approach combining seismic reflection, PS-InSAR (PSI), leveling and full 3D Ground Penetrating Radar (GPR), and thus overpassing the limits of each method. The analysis was conducted in a small village in the Alta Val Tagliamento Valley (Friuli Venezia Giulia region, NE Italy). Here, sinkholes have been reported for a long time as well as the hazards linked to their presence. Within past years, several houses have been demolished and at present many of them are damaged. The PSI investigation allowed the identification of an area with higher vertical velocities; seismic reflection imagined the covered karst bedrock, identifying three depocenters; leveling data presented a downward displacement comparable with PSI results; 3D GPR, applied here for the first time in the study and characterization of sinkholes, defined shallow sinking features. Combining all the obtained results with accurate field observations, we identified and mapped the highest vulnerable zone

THE CLASSICAL KARST GEOPARK

This special book, entitled „The Classical Karst geopark“, bears witness to a successful cross-border cooperation that will lead to the creation of a cross-border geopark in the Karst region. The publication is one of the results of the GeoKarst project, co-funded within the framework of the Interreg V-A Italy-Slovenia Cooperation Programme 2014-2020, while the contents produced by the Italian partners were financed by the Geological Survey of the Central Directorate for Environmental Protection, Energy and Sustainable Development of the Autonomous Region of Friuli Venezia Giulia (RAFVG). The idea of a cross-border geopark originated during the definition of the proposal of the strategic project KRAS-CARSO (Cross-border Cooperation Programme Slovenia-Italy 2007-2013) and proved to be most appropriate during its implementation. In fact, the feasibility Study on the creation of the geopark showed in technical, economic-managerial and participatory terms that the integration of the Karst area could be achieved through the creation of a cross-border geopark as a development tool for the sustainable use of resources and the well-being of the people living on the Karst Plateau. In 2015 and 2017, the 5 Slovenian and 12 Italian municipalities, which comprise the area concerned, decided to create a crossborder geopark, so that, since 2018, the Geological Survey of RAFVG (coordinator for the Italian part of the geopark) and the Municipality of Sežana (coordinator for the Slovenian part) have been intensively collaborating on the creation and management of the cross-border Karst geopark. The book describes all the main features of the Karst, which, as the “cradle” of karst studies, is of global significance from a culturalhistorical and scientific point of view. In the book you will note the frequent use of bilingual place-names and toponyms, this reflects the rich history of the area, which stands at the intersection of various cultures. Nowadays, the inhabitants of the Karst are mainly Slovenians and Italians. Slovenian language and culture in the Italian part of the Karst is covered by a law protecting the linguistic minority. Our sincere thanks go to all the contributors who have made this book possible