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South-eastern Dinarides comprise territories of four countries of SE Europe - Croatia, Bosnia & Herzegovina, Montenegro and Albania and their parts belonging to the Adriatic basin. The region consists mainly of highly karstified carbonate rocks and is characterised by a high precipitation rate. As a result, karst aquifers can accumulate large amounts of groundwater issuing at numerous karst springs, some being the world’s largest in terms of maximal flow. Locally, the annual total rainfall rate sometimes reaches 5,000 mm or even more, while an average specific groundwater yield of examined karst aquifers ranges from 40 to 50 l/s/km2. However, as discussed in this paper, the region also has many contrasts: abundant water reserves yet water shortage in certain parts, natural phenomena and wonders yet limited sources of life, good natural water quality marred by its vulnerability to pollution, feasible engineering solutions accompanied by their partly negative impact on environment, and water management at the national level contrasting with the transboundary character of most large aquifers. Doubts whether waters from this “treasury” are utilised in the best way and what the prospects are for their sustainable use and protection in the future are also analysed in the text.

The Tangab Dam was constructed at a unique geological structure, within a karst valley at the deepest point of a saddle-shaped feature which was formed by tectonic compression of a post-folding shear zone and later uplifting by two salt diapirs. The reservoir water-tightness system was composed of a 20-m-deep cutoff wall, and a 180-m-deep hanging grout curtain with 256 m and 206 m extension, respectively, into the left and right abutments. Since impounding of the reservoir in 2009, water leakage has occurred in 5.8 km downstream preexisting karst springs. To reduce water leakage, two additional grout curtains, as well as extensive treatment works, were added by injecting 11,055 t of cement into the karst bedrock. However, grouting was not as effective as it was expected to be, and the reservoir never filled to its designed normal volume. The fluctuation of water levels in the reservoir and downstream boreholes indicated that grouting successfully reduced head loss in water flow. The reservoir carries the potential to seep water into the karst aquifer along a vast zone at each valley bank since the seepage windows were not covered completely by the hanging grout curtains. The engineering problems occurred at the Tangab Dam site illustrate that conditions where the reservoir is perched above the groundwater and separated with the hanging river valleys are some of the most challenging karst terrains for dam construction in which the successful reservoir impoundment cannot be guaranteed, even by an extensive grouting and sealing program.

The distribution and flow of groundwater in karstified rocks can be extremely complex and not readily predictable, a far from friendly environment for constructing dams and reservoirs. There have been many expensive failures such as unacceptable leakage rates at and around dams, and/or reservoirs that could not be filled to the design levels. This is never the fault of site geology but always of human mistakes due to inadequate investigation programmes and/or erroneous interpretation of the karst processes at work. Remedial works are expensive, time-consuming and frequently do not justify the money invested. As a result, those undertaking engineering works in karst terrains may approach with two fears—of the exceptional risk and/or of a failure. The key question, so often, is whether to build the dam in karstified rocks or keep away from such a risky environment. However, construction of water storage reservoirs is essential in many karst regions for socio-economic development. The challenge must be accepted. Based on much field experience, the best practices for selection of adequate dam and reservoir sites are defined and illustrated with specific examples from many different climatic, topographic, lithologic and hydrogeologic settings in Europe and Asia. This work emphasises that the amount of certainty or uncertainty in the crucial parameters—geological structure, groundwater regime, intensity and depth of karstification—should be recognized.

The Commission on Karst Hydrogeology, also known as the Karst Commission (KC), was founded in 1970 in Neuchâtel, Switzerland, and it is an important part of the International Association of Hydrogeologists (IAH). The general idea was to organise a group of hydrogeologists from different countries, with relevant experience in karst hydrogeology, to promote cooperation among scientists interested in karst topics, exchange experiences and, particularly, create an optimal strategy for groundwater resources development. From foundation until today, more than 40 formal meetings and many informal KC gatherings (including field trips) have been convened in different karst regions, and a number of papers and books have been published by KC members. The first publication in the IAH book series International Contributions to Hydrogeology (the “blue books”) was on the subject of karst, presenting the experiences gleaned from a number of development projects from various karst regions, as well as bibliographic data on karst research of the time. Today, the KC is one of the most active IAH groups, with 70 permanent members from 6 continents and many young researchers, whose work is supported by funding and regular awards. The KC members have led or have been involved in many projects run with international cooperation. The two largest, completed in the course of the past decade, are the World Karst Aquifer Map (WOKAM) and the Dinaric Karst Transboundary Aquifer System (DIKTAS) projects. This paper summarizes the history of the KC to date.

SWIR imaging bears considerable advantages over visible-light (color) and thermal images in certain challenging propagation conditions. Thus, the SWIR imaging channel is frequently used in multi-spectral imaging systems (MSIS) for long-range surveillance in combination with color and thermal imaging to improve the probability of correct operation in various day, night and climate conditions. Integration of deep-learning (DL)-based real-time object detection in MSIS enables an increase in efficient utilization for complex long-range surveillance solutions such as border or critical assets control. Unfortunately, a lack of datasets for DL-based object detection models training for the SWIR channel limits their performance. To overcome this, by using the MSIS setting we propose a new cross-spectral automatic data annotation methodology for SWIR channel training dataset creation, in which the visible-light channel provides a source for detecting object types and bounding boxes which are then transformed to the SWIR channel. A mathematical image transformation that overcomes differences between the SWIR and color channel and their image distortion effects for various magnifications are explained in detail. With the proposed cross-spectral methodology, the goal of the paper is to improve object detection in SWIR images captured in challenging outdoor scenes. Experimental tests for two object types (cars and persons) using a state-of-the-art YOLOX model demonstrate that retraining with the proposed automatic cross-spectrally created SWIR image dataset significantly improves average detection precision. We achieved excellent improvements in detection performance in various variants of the YOLOX model (nano, tiny and x).

Video stabilization is essential for long-range electro-optical systems, especially in situations when the field of view is narrow, since the system shake may produce highly deteriorating effects. It is important that the stabilization works for different camera types, i.e., different parts of the electromagnetic spectrum independently of the weather conditions and any form of image distortion. In this paper, we propose a method for real-time video stabilization that uses only gyroscope measurements, analyze its performance, and implement and validate it on a real-world professional electro-optical system developed at Vlatacom Institute. Camera movements are modeled with 3D rotations obtained by integration of MEMS gyroscope measurements. The 3D orientation estimation quality depends on the gyroscope characteristics, we provide a detailed discussion on the criteria for gyroscope selection in terms of the sensitivity, measurement noise, and drift stability. Furthermore, we propose a method for improving the unwanted motion estimation quality using interpolation in the quaternion domain. We also propose practical solutions for eliminating disturbances originating from gyro bias instability and noise. In order to evaluate the quality of our solution, we compared the performance of our implementation with two feature-based digital stabilization methods. The general advantage of the proposed methods is its drastically lower computational complexity, hence, it can be implemented for a low price independent of the used electro-optical sensor system.

Karst evolution in gypsum and anhydrite rocks depends predominantly on the intensity of the dissolution. The process starts slowly by dissolution along narrow discontinuities such as joints and bedding planes and becomes much more intensive when the apertures have been opened enough for flow to become faster and turbulent.

Evaporite karst is developed widely throughout the world, though it is more common in the northern hemisphere, reflecting the current distribution of evaporite formations.

Understanding the properties of natural evaporite karst is a complex task, whether the data are needed for dam and reservoir construction, for water supply or simply for advancing scientific knowledge.

A number of dams and reservoirs constructed in soluble evaporite rocks all over the world have been affected by dissolution. From the beginning of the twentieth century, more than sixty dams have been affected by gypsum and salt dissolution problems. Some of the dams failed to retain water up to their design levels due to extensive leakage, some of them collapsed catastrophically, some others were abandoned, and some reservoirs suffer due to severe solute pollution of the stored water. Numerous dams in evaporites, mostly in gypsum, need rehabilitation: e.g., in Algeria, Argentina, Armenia, Azerbaijan, China, Dagestan, Georgia, Germany, Guatemala, Iran, Iraq, Jordan, Peru, Russia, Switzerland, Spain, Tajikistan, Tunisia, USA, Uzbekistan, Venezuela.

The most common evaporite rocks encountered at dam sites and reservoir areas are the calcium sulfate minerals, gypsum and anhydrite, and salt, the principal chloride (halite) mineral.

Evaporites are extremely vulnerable geological formations for construction of any large structure, particularly for dams and reservoirs. During the operation of dams and reservoirs in karstified evaporite rocks, a number of different destructive processes may endanger their integrity.

Prevention and remediation of public structures in evaporites are much more complex than in karstified carbonate rocks. The large number of documented examples of dam and reservoir problems in evaporites confirms this opinion. Much lower mechanical strength and much higher solubility when in contact with water (particularly if it is flowing or under pressure) determine that these rocks are dubious and hazardous foundations for dams.

Karst terrains have been modified and adapted through a range of human activities as the need for flood control, irrigation, food production, hydropower production and other resources has increased. Successful reclamation projects require construction of dams and reservoirs. Karst terrains present the most complex working conditions for dam foundation and realization of safe reservoir space. Practical engineering solutions are extremely complex and the need for successful solution requires serious investigations and the cooperation of a wide spectrum of scientists and engineers. A wealth of data on dam projects in karst has been collected and presented in this book. Since reservoirs in karst may fail to fill despite extensive investigations and remediation treatment the book includes a description of failures as well.

As the region of Eastern Herzegovina and the Boka Kotorska (Kotor Bay) area is one of the most highly karstified areas in the world, its hydrogeological properties, typical for karst, are extremely exposed. The main erosion base-levels for surface and underground waters of that region are: the Neretva River valley in the west, the Adriatic Sea and Dubrovnik littoral in the south and Boka Kotorska in the east. At the same time it belongs to one of the most investigated karst regions in the world known as the Dinaric Karst. The basic theories related to the nature of karst are based on the multidisciplinary and long-lasting investigation of this particular region. World famous karstologists such as Cvijic, Grund, Katzer and many others created crucial theories of karstology based on investigations and analysis of the Dinaric Karst. Many large and successfully constructed structures (dams, reservoirs and tunnels) of the region also became the basis for the development of engineering karstology. Massive karst investigation works were also performed during the twentieth century. The accumulated data and knowledge have been presented at many scientific conferences and has also appeared in many publications. The text below presents in brief, the general natural properties of the region and represents only a small part of the available data.

The construction of an underground dam and reservoir to provide an artificial water storage and karst control groundwater discharge regime is one of the most complex systems of tapping structure in karst. There are not many examples of underground dams, which increase the importance of risk management in their construction. This study proposes a procedure for constructing the underground karst reservoirs, focusing on the example of Perucac spring located in the Dinaric karst in Western Serbia. Possible effects of building of the underground reservoir are analyzed and a solution for a tapping structure is proposed. The applied concept is based on the karst groundwater budget, which provides valuable information on storage changes in the karst aquifer, enables further predictions of the optimal exploitation rate, and facilitates karst groundwater management. The results of this study give a basis for several possible technical solutions for a future tapping structure. These solutions were additionally analyzed in the process of multicriterial ranking to find the optimal process.

Anisotropy and heterogeneity of karstified rocks make them the most problematic media for various interventions which are needed in engineering practice. The long history of attempts to adapt karstic nature to human needs started with the utilization of karstic aquifers: tapping large springs, transferring their waters to the long distances, improving minimal flows or capturing fresh water in coastal areas. During the 20th century the number of other challenges such as building dam and reservoirs, and constructing roads and railways, bridges, tunnels, new settlements open a new era in engineering works but also in collecting new knowledge and experience for the karstology and hydrogeology sciences. Today, almost no engineering projects can be implemented without a proper environmental impact assessment, which establishes a better balance between human and ecological needs. Inženirski izzivi v Krasu Anizotropija in heterogenost zakraselih kamnin sta lastnosti, ki povzrocata, da so te najbolj problematicen medij za razlicne posege, ki so potrebni v inženirski praksi. Dolga zgodovina poskusov, da bi prilagodili krasko naravo clovekovim potrebam se je zacela z izrabo kraskih vodonosnikov: izkoriscanje velikih izvirov, prenos vode na dolge razdalje, povisevanje minimalnih pretokov ali zajemanje vode na obalnih obmocjih. V 20. stoletju je stevilo drugih izzivov, kot so gradnja jezov in rezervoarjev, cest in železnic, mostov, predorov, novih naselij odprla novo obdobje v inženirstvu. Poleg tega je botrovala zbiranju novih krasoslovnih in hidrogeoloskih znanj in izkusenj. Danes skoraj noben inženirski projekt ne more biti izveden brez ustrezne presoje vplivov na okolje, kar vzpostavlja boljse ravnotežje med clovekovimi in ekoloskimi potrebami.

Akkopru Dam, which is under construction, is located at Dalaman Basin in the southwest of Turkey. The base rock at the Akkopru dam site and reservoir area is autochthon Aktas limestone and Gokseki flysch formation. Allochthon Cehennem Deresi limestone, a complex series of ferro- (melange) and peridotite–serpentine units, overlay this unit with tectonic contact. These units are covered by young sedimentary series. The outcrops of karstified Aktas limestone are observed at 2 km upstream of the dam site, at the right reservoir abutment. This unit is very permeable and the groundwater level is very deep, 100–116 m below the Dalaman riverbed. After impoundment, 250,000 m2 of this unit will be submerged. Groundwater which percolates in this unit discharges at the coastal springs. This study analyzed the watertightness of Akkopru reservoir related to the karstified limestone in the left reservoir bank and discussed possible options of remedial works to reduce seepage.

(Priredio Petar Milanović-Trapo prema: Benito Giorgetta, Il Vangelo strabico, Anno ‘A’, Messaggero, Padova, 2010.)

A karst environment is a particularly sensitive and risky geological formation for the infrastructure construction from the micro to the mega scale. The hydraulic properties and specific regime of groundwater in karst are, in many cases, the source of catastrophic failures. The most common destructive influence of groundwater is the consequence of: massive turbulent flows; the fast erosion of unconsolidated deposits in caverns and joints; the great kinetic energy of underground flows; propagation of hydraulic pressure at large distances (piston effect); and the enormous hydraulic pressures created in periods of full aquifer saturation, including water-hammer and air-hammer effects due to rapid fluctuation of the water levels. Despite extensive investigations, the destructive impacts are mostly unpredictable in space and time. In many cases these destructive processes take time to become established but final effects appear abruptly, causing considerable damages or failures. The most common consequences of these impacts are subsidence at the urban areas, along the roads and railways, as well as at the bottom of reservoirs; water seepage from reservoirs; break-in of groundwater under high pressure during underground excavation; destruction of surface remediation structures; destruction of tunnel lining; degradation of grout curtains, induced seismicity; decreasing of downstream spring discharges; endangerment of underground species; and the creation of many other unpredictable and unexpected problems. Some dam failures (empty reservoirs) or collapses (entire buildings and factories sinks) were catastrophic. Successful remediation solutions require serious and comprehensive investigations including long period monitoring of groundwater regimes and (in many cases) remedial works during the lifetime of the structure. During construction modifications and adaptations of structures are very common in karst. Persistent, time-consuming and expensive remedial works during the lifetime of the structure are no exception, but, rather, they are the rule.

Construction of dams and reservoirs in karst is historically known as a very risky task. Inspite of very detailed geophysical investigations and repeated sealing treatments, the possibility for dam failure cannot be eliminated. In the karst environment, with its highly random distribution of dissolution features, some uncertainties always remain. The final determination of the adequacy of sealing measures comes after the first reservoir impoundment or even later. In many worldwide examples, watertightness treatment during dam construction was only partially successful, with some remedial work after impoundment being quite common. However, in some cases, the problem is simply too complicated and cannot be overcome. Special approaches have to be undertaken in order to prevent seepage from reservoirs. The key elements are a good geological map and proper geophysical investigations. These investigations are key prerequisites of dam construction in karst and cutting costs through restricting them usually results in increasing the chance of project failure. To deal with karst successfully, innovation, engineering practice, execution feasibility, and commercial understanding have to be undertaken. Grouting alone is definitely not adequate in the case of large karst conduits. Special treatment of large caverns and flexibility during grout curtain execution, including modifications and adaptations on the basis of the geological findings, should be the standard procedure for dam construction in karst to minimize risk. Such an approach is the basic worldwide rule in the fight against leakage from dam sites and reservoir abutments.

One of the most complex systems of tapping structure in karst is construction of an underground dam and reservoir to provide artificial water storage and a karst controlled groundwater discharge regime. Examples of underground dams are not so numerous; and, therefore, the risk component in their building is much emphasized. In this paper, a proper procedure for building a support system for constructing underground karst reservoirs was proposed, focusing on the example of the Perucac spring, located in Dinaric karst, in Western Serbia, and analyzing possible effects of building an underground reservoir and selecting tapping using this procedure.

The region of eastern Herzegovina and Dubrovnik coastal belt is one of the hydrogeologically and hydrologically most interesting regions of Yugoslavia karst. The main water course in the region is the Trebisnjica river, the largest sinking river in Europe. All the poljes in the catchment area are temporary flooded, hydrologically separated, and closed karst entities. Enormous quantities of available water are not evenly disturbed neither in the time nor in the space. The Trebisnjica Hydrosystem project uses the basic concept of total water regime organization and its multipurpose utilization. With the construction of seven dams, six artificial reservoirs, six tunnels (with total length, 57 km), and four canals (with total length 74 km) the natural regime of surface and underground waters has been completely changed.

With the construction of a 123 m high dam, a large and permanent karst spring was flooded by water, about 75 m deep. The annual average discharge of this zone is 80 m 3 s −1 . The aquifer zone which discharges through this spring was formed under complex tectogenetic conditions of Dinaric karst. The most prominent structures are overthrusts and reverse faults. These structures have caused the formation of separate karst aquifers which are arranged stepwise behind an existing karst spring. Transformation of these aquifers into a single karst aquifer has taken place in the later phases of the karst evolutionary process. The velocity of the underground flows in this aquifer, which depends on the actual hydrologic situation and on the level of the water table, is between 0.9–14.0 cms −1 . Water table fluctuations are very rapid with amplitudes up to 120 m. Photogeological analysis defines the tectonic zones along which underground karst channels of huge drainage capacity are formed. Extensive hydrogeological and geophysical research and hydrologic and hydrogeologic monitoring was carried out in the catchment area. In order to define the influence on the karst aquifer regime of flooding of springs a correlative analysis has been performed between the index of previous precipitation, the water level in the reservoir, the underground water level in the immediate vicinity of the spring and in the distant parts of the aquifer, and the inflow into the reservoir. The multiple correlation coefficients obtained show mutual dependence of most of parameters analysed. The analysis has shown that the flooding of springs has some influence on the hydrological conditions of the upstream polje and the surface in the immediate tributary area. There is also an evidence of formation of an underground reservoir in the karst aquifer. It is connected with the downstream aquifers which are under the influence of the reservoir being formed deep in the banks, and has some influence on the layout of the natural watersheds. As a consequence of flooding of spring and reservoir formation there is induced seismicity in the catchment of the spring.

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