Surface and subsurface karst geomorphology in the Murge (Apulia, Southern Italy)

The Murge (Apulia, southern Italy) is the main karst area in the central part of the region, extending from the inland plateau to the Adriatic coastline. Along this transect, a relief energy of a few hundred meters is reached. Even thoughsuchrelief may seem small when compared to mountain karst areas, actually it is not for Apulia, a very flat carbonate region that acted as the foreland during the building up of the Apenninic Chain in Miocene time. Murge can be subdivided into two sectors: HighMurge, the inland plateau, where remnants of an ancient tropical karst are still recognizable; and Low Murge, closer to the sea, withsmoother karst morphologies and landforms. Here, some of the most remarkable underground karst systems of Apulia are located: the Castellana caves, a show cave that has been opened since 1939 to tourists (only a few months after the discovery), and the Pozzo Cucù karst system. Overall, the two systems (that are located few hundreds of meters apart) are more than 5,5 km long. In addition, many other karst caves are widespread in the territory, showing different typologies, from percolation shafts, to intrastratal caves, to tectonically-controlled caves, down to marine caves along the coastline. At the surface, other interesting morphological features related to karst may be observed, the main one being the Canale di Pirro polje, whichcuts the SE Murge withan E-Wstrike, until its easternmost reachagainst the Murge fault line scarp. This latter is the main morphological feature intervening between the Murge plateau and the Adriatic plain. In this article the karst morphological features of Murge are depicted, putting together surface and underground data, in the effort to contribute to the recognition of the main phases of development of karst processes in the region

Karst Geo-hazards: Causal Factors and Management Issues

Karst terranes exhibit spectacular landforms that are often exploited as natural parks and show caves, and hosts very important natural resources. Further, karst terranes cover 20% of the Earth’s surface and provides 20−25% of high-quality groundwater for drinking water. The fragility of karst environments makes it highly vulnerable to a variety of different geological hazards (or geo-hazards). This is due to its peculiar geological and hydrological features such as sinkholes and caves. In particular, the strict connection between surface and subsurface features emphasizes the fragile nature of karst. The occurrence of geo-hazards in karst terranes greatly differs from other natural settings. Natural and man-induced subsidence and sinkholes, slope movements favored by karst conduits and caves, flash floods related to inability of the system to manage water from heavy rainstorms, and pollution caused directly or indirectly by human actions are the main types of geo-hazards typical of karst terranes. Although mostly related to natural processes, their occurrence and consequent damage to both the natural and anthropogenic environment are often caused or exacerbated by man. As a consequence, management of karst terranes cannot be enacted without taking into account the peculiar features and behavior of karst terranes and aquifers, and the delicate balance with the different types of geo-hazards that may occur. Specific management actions should, therefore, be pursued in this fragile environment, with the intention of safeguarding the natural resources, biota, and population.Naravne nesreče na Krasu: Vzročni dejavniki in vprašanja upravljanjaKraška območja odlikujejo spektakularne reliefne oblike, ki so pogosto povod za ustanovitev naravnih parkov ali turističnih jam, ter pomembne naravne vire. Kras pokriva okoli 20% kopnega in zagotavlja okoli 20−25 % potreb po pitni vodi. Krhkost kraških okolij so razlog za njihovo visoko dovzetnost za različne geološke in druge naravne nesreče. Razlogi so v posebnih geoloških in hidroloških značilnostih, kot so vrtače in jame. Krhko naravo krasa zlasti poudarja tesna povezava med površinskimi in podzemnimi oblikami. Pojavljanje naravnih nesreč v krasu se močno razlikuje od tistih v drugih naravnih okoljih. Naravno in s strani človeka povzročeno pogrezanje, udori in plazenje so pod močnim vplivom kraških kanalov in jam. Poplave so povezane z nezmožnostjo sistema prevajati nalivne vode. Onesnaženje, ki ga človek povzroči posredno ali neposredno s svojimi aktivnostmi, so poglavitne nesreče v krasu. Čeprav so naravne nesreče večinoma povezane z naravnimi procesi, njihovo pojavljanje in posledično škodo tako za naravno kot antropogeno okolje pogosto povzroča ali pospeši človek. Upravljanje kraških območij zato ne more biti načrtovano brez upoštevanja specifičnih lastnosti in obnašanja kraških pokrajin, vodonosnikov in krhkega ravnotežja med različnimi vrstami nesreč, ki se lahko pojavijo. Zato bi bilo z namenom varovanja naravnih virov, živih bitij in prebivalstva treba uvesti posebne ukrepe upravljanja v tem občutljivem okolju.

Recent advances in karst research: from theory to fieldwork and applications

Karst landscapes and karst aquifers, which are composed of a variety of soluble rocks such as salt, gypsum, anhydrite, limestone, dolomite and quartzite, are fascinating areas of study. As karst rocks are abundant on the Earth's surface, the fast evolution of karst landscapes and the rapid flow of water through karst aquifers present challenges from a number of different perspectives. This collection of 25 papers deals with different aspects of these challenges, including karst geology, geomorphology and speleogenesis, karst hydrogeology, karst modelling, and karst hazards and management. Together these papers provide a state-of-the-art review of the current challenges and solutions in describing karst from a scientific perspective

Gypsum Karst in the CrotoneProvince (Calabria, Southern Italy)

 Področje Kalabrije v južni Italiji predstavlja izreden primer krasa v sadri, ki vključuje tudi evaporitne kamnine triasne do miocenske starosti. Triasni evaporiti se pojavljajo v sekvenci debeli okrog sto metrov na področju obmorskega hrbta na zahodni obali Kalabrije. Na drugi strani pa evaporiti mesinske starosti obširno izdanjajo na vzhodu, v krotonskem bazenu. Pričujoči prispevek opisuje glavne značilnosti krasa v sadri (od površinske kraške morfologije do razvoja jam) na vzhodnem predelu Kalabrije. Krotonski bazen je med najbolj zanimivimi področji evaporitnega krasa v Italiji: tam najdemo različne površinske kraške oblike kot so vrtače, slepe doline, zaprte depresije, globoke in ozke soteske, kjer zasledimo intenzivna pobočna gibanja. Številni vhodi jam so na dnu vrtač. Jama Grave Grubbo, dolga prek 2.500 m, je ena daljših jam v Italiji v evaporitih. Na raziskovanem področju je prišlo do številnih sprememb, še posebno zaradi kmetijske dejavnosti in zaradi nezadostne pozornosti lokalnih oblasti do te izjemne pokrajine. Posebna vrednost krasa v sadri v Kalabriji še ni v celoti ovrednotena. Prišlo je namreč do onesnaženja številnih jam in posledično do znižanja kakovosti vode, ki teče v kras. The Calabria region of southern Italy presents remarkable examples of gypsum karst, involving evaporite rocks ranging in age from Trias to Miocene. Triassic evaporites are limited to a sequence of about one hundred meters of thickness in the Coastal Chain, on the western Calabrian coast. Messinian evaporites, on the other hand, extensively crop out to the east, in the Crotone Basin. The present contribution intends to describe the main features of gypsum karst in the latter area, from the surface karst morphology to the development of caves. The Crotone Basin is among the most interesting areas as regards evaporite karst in Italy: a variety of surface karst landforms is there present, including dolines, blind valleys, closed depressions, and deep and narrow canyons intensely affected by slope movements. Many caves are located at the bottom of the dolines, as Grave Grubbo which, with a length over 2,500 meters, is one of the longest Italian caves in evaporites. The study area has experienced several transformations, mostly due to agricultural activity and to scarce attention paid by local administrators toward this unique naturalistic landscape. The high value of Calabrian gypsum karst is thus not fully exploited, and several cases of degradation of the caves have been registered, even with consequences for the quality of water flowing in the karst systems

Structural control on development of karst landscape in the Salento Peninsula (Apulia, SE Italy)

Apulia region (SE Italy) is particularly prone to karst processes, due to the extensive presence of carbonate rocks. Karst marks the whole region, and represent the main landscape features, with a variety of landforms ranging from large-size dolines, to poljes, and fluvial-karstic valleys; given the configuration of Apulia, a great role is also played by coastal karst landforms. The Salento peninsula, in southern Apulia, is characterized by very low relief and cropping out of different types of carbonate rocks, ranging in age from Cretaceous to Quaternary. Recognition of karst features in this setting, and the likely implications for geohazards, is quite difficult, because of the subtleness of the features, and the facility for man to cancel or modify them. Nevrteheless, the presence of dolines is definitely a typical aspect of the area, which also implies some consequences in terms of risk to the built-up environment.This work focuses on the area of Barbarano del Capo, where two cover-collapse dolines are well known in the geological literature as Vora Grande and Vora Piccola. Despite morphometrical and stratigraphical features have already been investigated, few information are available about the hydro-geomorphological and structural settings of the area. This article presents the results of morphological and structural analyses, aimed at understanding the role played by tectonics in the development of karst features, and their evolution

Evaluating the Human Disturbance to Karst Environments in Southern Italy

Karst environments are extremely vulnerable to degradation and pollution. Although the carrying capacity of these natural environments is low, a variety of human activities is implemented on karst settings generating impacts at the surface and subsurface. To evaluate the degree of disturbance to typical karst environments in the Mediterranean basin, two areas have been selected in Apulia (south-eastern Italy). The human-induced effects are being assessed by applying a recently developed Karst Disturbance Index (KDI), based on a categorical framework encompassing physical, biological, and social aspects, and the evaluation of a number of indicators for each category. Scores are assigned to the indicators, to assess the severity and the extent of the human impacts on the karst environment. Knowledge of the study areas derives from a combined use of direct experience and field surveys, and the critical evaluation of data available from research articles and local organization reports. Since this approach is an holistic and comprehensive method, different scientific branches and law issues have been considered. The results so far obtained for the study areas highlight the urgent need of a sustainable management of anthropogenic activities: for example, quarrying and stone clearing, both extensively widespread, are among the most dangerous practices for karst surface and subsurface landforms in Apulia. These activities are heavily changing the original karst landscape and causing the partial or total destruction of natural caves. This study represents a preliminary evaluation of the human disturbance to karst in Apulia, but has to be necessarily integrated by further applications in other areas of the region, aimed at a better understanding of the potentiality of the approach and its feasibility in different karst settings

I Sinkholes nella Letteratura Scientifica Internazionale: una Breve Rassegna, con Particulare Riferimento Agli Stati Uniti D\u27America

Fenomeni di sinkholes sono diffusi in moltissimi paesi del mondo, in ambiti geologici e morfologici alquanto differenziati, e coinvolgono svariate litologie, sia nelle successioni di copertura che in quelle direttamente affioranti alla superficie. Il presente contributo intende fornire una breve rassegna, certamente non esaustiva, sullo stato dell’arte delle ricerche relative ai sinkholes in ambito internazionale. Esso consiste in una descrizione della più aggiornata e diffusa classificazione dei sinkholes e, a seguire, in descrizioni delle più tipiche casistiche di sinkholes nei vari paesi. Tra questi, viene dato particolare risalto agli Stati Uniti d’America (e, più in particolare, alla Florida), dove le ricerche su tali fenomeni sono state avviate da tempo e risultano estremamente approfondite

The Show Cave at “Gran Caverna de Santo Tomás” (Pinar del Rio Province, Cuba)

 Del jame Gran Caverna de Santo Tomàs, ki je eden najdaljših jamskih sistemov na Kubi, je urejen za turizem že od 1994. To je šesti nivo (od sedmih) tega kompleksnega kraškega sistema, katerega najnižji del je aktiven in teče skozenj potok Arroyo Santo Tomàs. Zaradi velike pestrosti kraških oblik, tako na površju kot v jami in zaradi pomembnih arheoloških odkritij, je jamo Gran Caverna de Santo Tomàs v zadnjih 10 letih obiskalo pomembno število turistov in znanstvenikov, kljub težavam zaradi oddaljenosti od glavnih turističnih poti po otoku. Več elementov potrjuje, da je upravljanje z jamo lep primer majhnega vpliva turizma na jamo. Med temi je omejeno število obiskovalcev v skupini, uporaba zgolj lesa za lestve in mostičke za dostop do jamskega vhoda ter uporaba akumulatorskih električnih svetilk (ne da bi bil v jami nameščen stalni sistem osvetljevanja). Zato ima Gran Caverna de Santo Tomàs velike možnosti da postane eno najpomembnejših mest na Karibih, kjer bi lahko na eni strani razvijali ekološki in trajnostni turizem, na drugi pa bi, zaradi svoje velikosti in dolžine, vabila mednarodne in kubanske jamarje ter znanstvenike k stalnim speleološkim in krasoslovnim raziskavam. At Gran Caverna de Santo Tomàs, one of the longest karst system of Cuba, a part of the cave is exploited since 1994 as show cave. It corresponds to the sixth level (out of the total of seven) of the complex karst system, which lowest part is still active today, being the present course of Arroyo Santo Tomàs. Even with the difficulties related to great distance from the main tourist routes of the island, Gran Caverna de Santo Tomàs was visited in the last 10 years by a significant number of tourists and scientists, due to its remarkable variety of karst landscape, at the surface as well as within the cave, and the important archaeological discoveries therein carried out. Management of the show cave is a good example of low-impact effect of tourism in a karst cave, as many features point out. Among these, the limited number of visitors allowed for each group, the choice in using only wooden ladders and passages to reach the cave entrance, and the adoption of rechargeable electrical light (without realizing any fixed light system in the cave). Gran Caverna de Santo Tomàs, therefore, has a high potentiality for becoming one of the best location in the Caribbean to develop an ecological sustainable tourism and, at the same time, due to its size and length, to allow international and Cuban cavers and scientiststo continue carrying out speleological and karst research.  

On the applicability of geomechanical models for carbonate rock masses interested by karst processes

Rock mass classification and geomechanical models have a particular importance for carbonate rocks, due to their peculiar fabric, variability of the main features, and scarce availability of experimental data. Carbonates are particularly sensitive to syn-depositional and post-depositional diagenesis, including dissolution and karstification processes, cementation, recrystallisation, dolomitisation and replacement by other minerals. At the same time, as most of sedimentary rocks, they are typically stratified, laminated, folded, faulted and fractured. The strength and deformability of carbonate rock masses are, therefore, significantly affected by the discontinuities, as well as by their pattern and orientation with respect to the in situ stresses. Further, discontinuities generally cause a distribution of stresses in the rock mass remarkably different from those determined by the classical elastic or elasto-plastic theories for homogeneous continua. Goal of this work is the description of the difficulties in elaborating geomechanical models to depict the stress–strain behavior of karstified carbonate rock masses. Due to such difficulties, a high degree of uncertainty is also present in the selection of the most proper approach, the discontinuum one or the equivalent continuum, and in the numerical model to be used within a specific engineering application as well. The high uncertainty might cause wrong assessments as concerns the geological hazards, the design costs, and the most proper remediation works. Even though recent developments in the application of numerical modeling methods allow to simulate quite well several types of jointed rock masses, as concerns carbonate rock masses many problems in representing their complex geometry in the simulation models still remain, due to peculiarity of the structural elements, and the presence of karst features. In the common practice, the improper use of the geomechanical models comes from a superficial geological study, or from the lack of reliable geological and structural data that, as a consequence, bring to erroneous evaluations of the influence of the geological-structural features on the in situ stress state and the stress–strain rock mass behavior

A database on flash flood events in Campania, southern Italy, with an evaluation of their spatial and temporal distribution

Abstract. This study presents an historical database of flash flood events in the Campania region of southern Italy. The study focuses on small catchments characterized by intermittent flow, generally occurring during and after heavy rainstorms, which can be hydrologically defined as small Mediterranean catchments. As the outlet zones of these catchments (consisting mainly of alluvial fans or fan deltas) are highly urbanized in Campania, the population living in the delivery areas is exposed to high risk. Detailed scrutiny and critical analysis of the existing literature, and of the data inventory available, allowed us to build a robust database consisting of about 500 events from 1540 to 2015, which is continuously updated. Since this study is the first step of a longer project to perform a hazard analysis, information about time and site of occurrence is known for all events. As for the hazard analysis envisaged, collecting information about past events could provide information on future events, in terms of damage and also spatial and temporal occurrence. After introducing the issue of flash floods in Italy we then describe the geological and geomorphological settings of the study area. The database is then presented, illustrating the methodology used in collecting information and its general structure. The collected data are then discussed and the statistical data analysis presented