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

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

Kinematics of the Southern Rhodope Core Complex (North Greece)

The Southern Rhodope Core Complex is a wide metamorphic dome exhumed in the northern Aegean as a result of large-scale extension from mid-Eocene to mid-Miocene times. Its roughly triangular shape is bordered on the SW by the Jurassic and Cretaceous metamorphic units of the Serbo-Macedonian in the Chalkidiki peninsula and on the N by the eclogite bearing gneisses of the Sideroneron massif. The main foliation of metamorphic rocks is flat lying up to 100 km core complex width. Most rocks display a stretching lineation trending NEâ SW. The Kerdylion detachment zone located at the SW controlled the exhumation of the core complex from middle Eocene to mid-Oligocene. From late Oligocene to mid-Miocene exhumation is located inside the dome and is accompanied by the emplacement of the synkinematic plutons of Vrondou and Symvolon. Since late Miocene times, extensional basin sediments are deposited on top of the exhumed metamorphic and plutonic rocks and controlled by steep normal faults and flat-ramp-type structures. Evidence from Thassos Island is used to illustrate the sequence of deformation from stacking by thrusting of the metamorphic pile to ductile extension and finally to development of extensional Plio-Pleistocene sedimentary basin. Paleomagnetic data indicate that the core complex exhumation is controlled by a 30� dextral rotation of the Chalkidiki block. Extensional displacements are restored using a pole of rotation deduced from the curvature of stretching lineation trends at core complex scale. It is argued that the Rhodope Core Complex has recorded at least 120 km of extension in the North Aegean, since the last 40 My

Characterisation of igneous terranes by zircon dating: Implications for UHP occurrences and suture identification in the Central Rhodope, northern Greece

2siThe occurrence of ultra high pressure (UHP) and high pressure (HP) relicts associated with oceanic material suggests the presence of a suture zone within the Rhodope Massif. Characterisation of the accreted igneous terranes and their relationship with the UHP/eclogite occurrences provide new constraints on the location of this suture. Single-zircon evaporation and sensitive high-resolution ion microprobe dating of orthogneiss protoliths define two groups of intrusion ages: Permo-Carboniferous and Late Jurassic–Early Cretaceous. Structurally, the Late Jurassic gneissic complex overthrust a unit with Permo- Carboniferous orthogneisses. A ‘‘melange zone’’ marked by mylonites, eclogites, amphibolites, and UHP micaschists separates these two units. We interpret these observations in terms of two distinct igneous terranes, the Thracia (Permo- Carboniferous) and Rhodope (Late Jurassic) terranes, separated by the Nestos suture, and assembled during the closure of an oceanic basin of the Tethys. Geochemically, the Late-Jurassic rocks are akin to subduction magmatism, possibly the same subduction that caused the UHP metamorphism of metasediments within the ‘‘melange zone’’. Observed UHP–HP relicts are restricted to the tectonic contact zone, suggesting that a single subduction/collison event can explain the occurrences of UHP relicts and eclogites in the Central Rhodope, and that subducted rocks are exhumed only within the Nestos suture.nonenoneTurpaud, Philippe; Reischmann, ThomasTurpaud, Philippe; Reischmann, Thoma

Dissemination through InFEA Project: the water, an inalienable right

6noWhile drawing up the Water Protection Plan, the Water Resources Department of the Friuli Venezia Giulia Region jointly with the Mathematics and Geosciences Department of the Trieste University has carried out a three-year study aimed at assessing the sustainability of the groundwater use in the Friuli Venezia Giulia Region. In this territory is still very common to get water from artesian wells for domestic purposes and to leave them flowing free. These so called “fountains”, widespread located in the Low Plain, can be considered an integral part of the popular culture, a sort of cultural heritage to be preserved. Their density varies considerably according to the geographic settlements distribution and to the boundary conditions. The withdrawals interest the artesian aquifer systems and being free flowing, withdrawals are real and much more than the needs. The unsustainability lies in the fact that, high quality waters, withdrawn from medium to high depths, end up in the sea through irrigation and drainage canals or go to feed the shallow phreatic aquifer system of the Low Plain without producing any recharge for the groundwaters. The study highlighted that more than 50% of the total used groundwaters come from the domestic wells that get the waters from the deep aquifer systems. These withdrawals are approximately 70 times more than the estimated demand (250l/day per person, for a European citizen). In the Friuli Venezia Giulia Region, even if do not exist a problem of water quantity, going on with the same way of living, there will be, for sure, a quality problem. In the system in fact, through the effective infiltration, worse quality waters go into the water cycle. Furthermore, this great discharge that reaches the drainage system causes malfunctions in sewage plants and an increase of the pumping costs. Then comes the need to raise awareness on this specific subject. Thanks to the national InFEA Project, Friuli Venezia Giulia Region, jointly with researchers of the Trieste University, started a dissemination program in the hydrogeology field. The foreseen activities, within the time, will involve all the Low Plain municipalities. The methodological approach involve all the primary schools (class 4 and 5), teachers, local administrators and citizens. To the scholars, after a starting front lecture (two hours for each class), a field daily activity is offered. At the end of the cycle, all the students are involved in an active cooperation allowing to realize posters, models, poems and short stories that are later presented during an evening dedicated to a discussion among researchers, politicians/administrators and citizens. The involvement of the young students (9-11 years old) with the constant and active participation also of the teachers, authorities, parents and citizens, can be considered an educational experience for everybody. At the same time, this creates a conscious awareness of the critical issues of our fragile territory.nonenoneCalligaris, C.; Zini, L.; Turpaud, P.; Iervolino, D.; Lippi, F.; Cucchi, F.Calligaris, Chiara; Zini, Luca; Turpaud, Philippe; Iervolino, D.; Lippi, F.; Cucchi, Franc

Capire il ciclo idrologico per una migliore gestione dell'irrigazione in viticoltura: dalle precipitazioni al suolo e di nuovo alla vite

The Project Acquavitis investigated soil water recharge and its utilization by grapevines in 6 vineyards belonging to 3 contexts characterized by different geological, hydrogeological and climatic characteristics during the growing seasons of 2020 and 2021. Here, we present the results obtained in 3 vineyards, each one representing a different context. The soils of each vineyard have been characterized from a granulometric and mineralogic point of view. Soil samples were collected at least three times during summer 2020 and 2021 to measure the soil water content and water potential and to analyze the oxygen and hydrogen isotopic composition of soil water. Together with soils, precipitations, surface water and groundwater (from wells or caves in proximity of the studied areas) were also sampled. For understanding which water, the grapevines exploit during the growing season, the isotopic composition of the waters was compared to xylem sap extracted from grapevine branches during the same sampling periods. In the Ceroglie vineyard (in the Italian Karst), sampling frequency was incremented during 2021 for determining the influence of single precipitation events on soil water recharge and soil water use from vines. Geophysical surveys were also conducted to Capire il ciclo idrologico per una migliore gestione dell’irrigazione in viticoltura determine soil depth in the area. The obtained results suggest that, in general, grapevines mainly utilize water from the upper soil layers. This was influenced by the good water availability in soils due to the relatively abundant rainfall in spring and/or summer during the two years of this study