Karst Polje Research Articles

Prostorna diferencijacija vrgoračkog područja na temelju krških prirodno-geografskih i društveno-geografskih obilježja

The area of Vrgorac is defined by a contrast between the high mountainous zones in the southwest and the low karst poljes in the southeastern part of the municipality. It is a relatively small area which includes a wide range of different natural-geographic and socio-geographic elements usually featured in karst zones with limestone basis. Considering the above mentioned features, the area of Vrgorac can be divided into several spatial zones. Specific natural geographic conditions have resulted in landscapes of distinctive Dinaric socio-geographical area which are still typical in some zones of Vrgorac, representing the dominant feature in the area in spite of the ever-increasing process of modernization and globalization with their impact on human activities and the environment.

Fractal approach in characterization of spatial pattern of soil properties

The objective of the study was to characterize spatial pattern of soil properties (CaCO3, soil organic carbon, P2O5, K2O, and clay content) using fractal concept. Total of 141 top-soil samples (0-30 cm) were collected on 1850 ha in karst polje (Petrovo polje, Croatia) and analyzed for listed soil properties. The semi-variogram method was used to estimate fractal dimension (D) value which was performed from both of isotropic and anisotropic perspective. The D value of soil properties ranged between 1.76 to 1.97, showing a domination of the short-range variations. The SOC and K2O fractal D values 1.79 and 1.76 respectively, exhibited a spatial continuity at the entire analysed range of the scale. The D value for P2O5 (1.97) showed a nearly total absence of the spatial structure at all scales. The CaCO3 and clay content indicated a multifractal behavior mainly attributed to effects of alluviation, differences in geology and its spatial changes and transitions. The results of anisotropic analysis of soil properties pattern have showed strong relations with directions and partial self-similarity over limited ranges of scales defined by scale-break. Finally, our results showed that fractal analysis can be used as a appropriate tool for the characterization of spatial pattern irregularities of soil properties and detection of soil forming factors that cause it.

SPECIFIC ROLES OF SOIL IN AGROECOSYSTEMS OF NERETVA AND TREBIŠNJICA RIVER BASIN

UDK 631.4(497.6)
 The diversity of soils and climate in the Neretva and Trebišnjica River Basin spreads from the lower, higher, high to very high zone over 2,000 meters above sea level. The most important agricultural land is in river valleys and karst poljes of belonging zones. Ameliorative systems are mostly out of function while actual systems are comprised of very intensive farming; vegetable growing, modern fruit plantations on the open field and protected areas (greenhouses), but also of the low-intensity farming system in a mountainous area. The current climate changes obviously are not a temporary phenomenon, but are a specific one; there are no more “dry” or “rainy years” as it was in the past -now we have both in the same year. In spring, the soil needs quick and efficient drainage of the sufficient water by drainage system, but in dry – vegetation period, compensation of water deficiency by irrigation is needed. Therefore, today's generation of decision-makers and users of soil as a public treasure cannot avoid the question as to which soil/land areas and at which way to focus investments. We propose the construction of multi-purpose water accumulation, to collect (excess) precipitation in autumn-winter season for irrigation in dry summer vegetation period, but it is necessary to focus land management on (pedo) biological properties and activity.

Environmental aspects and potential impacts of proposed water transfer scheme on sustainable water management in eastern Herzegovina

East Herzegovina is characterized by substantial water resources and abundant precipitation from October to May each year. As a result, the karst poljes of east Herzegovina are experiencing major, long-lasting floods during the rainy period and, conversely, insufficient recharge to the aquifer systems and rivers in the summer, often causing streams to completely dry out. Consequently, the karst poljes, which are the largest arable lands in the area, are rendered virtually useless during most of the year. To address this issue, the idea was born to build multi-purpose systems—the Trebisnjica Hydropower Scheme—in the so-called Lower Horizons and Upper Horizons, the primary and ultimate goal being the management of water resources in the area. The Lower Horizons scheme, which encompasses hydraulic structures, surface reservoirs, hydroelectric power plants, irrigation systems and drinking water supply facilities, was largely completed in the 1970s. The outstanding Upper Horizons project calls for comprehensive development of the water regime, including water resources management, social, environmental and energy components, as well as the transfer of water from the Neretva River Basin to the Trebisnjica River Basin (still under evaluation). Namely, interbasin transfer would reduce the discharges of the Neretva’s left tributaries: the Buna, the Bunica and the Bregava, but must not threaten minimal natural flows. The hydraulic model and preliminary environmental impact assessment indicate that there will be no significant adverse impacts; however, continuous monitoring of the effects during both construction and operation is mandatory.

Evolution of a karst polje influenced by glaciation: The Gomance piedmont polje (northern Dinaric Alps)

Gomance is a piedmont karst polje in the northern Dinaric Alps presenting geomorphological and sedimentological evidence of past glaciation. During the Pleistocene the polje was situated at the edge of the Snežnik and Gorski Kotar ice fields from where two outlet glaciers reached Gomance. The morphogenesis of the polje was reconstructed by means of geomorphological mapping, sedimentological studies, and ground penetrating radar (GPR) measurements, supported by hand-drillings. With GPR an almost entirely buried moraine system was also imaged and mapped, crucial in reconstructing the polje history. The depression was karstified and well drained without any surface streams before the Last Glaciation. When the glacier front reached the depression, the entire floor became covered by glacial and outwash deposits. Surface runoff dominated over karst drainage in a large part of the polje, particularly where distal outwash deposits with low effective porosity functioned as an aquitard. These deposits diverted surface drainage toward the lowest edge of the polje, which functioned as a ponor front along the entire length. The outwash system of the Gomance polje was active during the Last Glaciation as suggested by radiocarbon-dated outwash deposits.

砿都における景観の特長に関する研究

Limestones have been playing important roles in offering fundamental materials for construction of public infrastructure. There are many limestone quarries in Japan and they formed the cement industrial cities around them with conspicuous industrial landmarks. Cement industries brought wealth to the city and advanced infrastructures, such as high-graded trunk roads or rich architectures. In addition, huge cement works form characteristic technoscape (industrial landscape) which is cherished by local people as their home landscape. This study manifests the landscape properties of cement and limestone industrial cities, by observing 37 cities in Japan, with in-situ survey of the landscape, bibliographic and folklore survey of lime-originated folk customs, festivals or local songs. The findings of this study are, (1) Prominent technoscape of cement is formed in process of cement production, lime transportation and lime quarry, (2) Landscape of limestone-originated nature, such as karst valley, limestone cave, or karst polje (large elliptical depression) is formed nearby, and (3) Lime-originated natural landscape formed by easy erosion of limestone took on sublime appearance, generated animism, and it has been existing with deformation or relocation by companies after industrialization.

Morfogeneza kr�kih polja na otoku Visu, Hrvatska

Karst poljes are the most characteristic feature of Dinaric karst area. The number of poljes identified on the island of Vis (Croatia) differs according to the various authors who have studied the island. Considering the various existing definitions of polje in previous studies, in this paper we propose a set of criteria for identifying poljes in karst terrain using Geographic Information System. This enabled the identification of six poljes on the Vis Island, whose formation is predetermined by tectonic structures. Moreover, processes are frequently inferred by neotectonic (both uplift and subsidence) according to the analysis of longitudinal and transverse profiles gradients affecting balance of these morphologies. Since they are not hydrologically active in present hydrological conditions, poljes on Vis Island can be considered to be paleo - overflow or structural poljes.

Geomorphological evolution of the Vendicari karstic coastal lake system (SE Sicily, Italy)

The Vendicari coastal lake system (SE Sicily) presents several geomorphic characteristics, which suggest it was originated as a part of a 6 km long karst polje during the Late Pleistocene sea level lowstand. Exhumed cryptokarst karren and terraced concentric surfaces point to this working hypothesis. The generation of this depression could have been favoured by the low to moderate neotectonic activity in the zone, which consisted in slight uplifting and subsequent fracturing. Open joints in the Vendicari Pleistocene carbonates show a radial outline with the prevalence of NNW-SSE discontinuities. Once formed, polje evolution would have consisted in a progressive compartmentalisation and splitting into several polje bottoms, some of which form a part of the present Vendicari lake system and are surrounded by stepped corrosion surfaces. The postglacial sea level rise had drowned most part of the original polje, which can be still recognized in the inner continental shelf. Sea level stabilization after the Holocene eustatic maximum favoured the development of a beach barrier, which generated additional coastal lakes of lagoonal type.

Ivan Gams – karstologist

Academician Ivan Gams is Slovenia's best known researcher of karst and the most prolific author of works on karst. During his first job at the Institute of Geography of the Slovenian Academy of Sciences and Arts, he started researching the karst surface and underground. He published several in-depth publications on karst caves, the most well-known being the studies of the shaft Triglavsko brezno in the 1960's. Right from the beginning, he focused on issues to which he then dedicated more or less his whole life − and which were also widely recognized by professional public both at home and abroad −, namely corrosion intensity determined by the hardness of water and the discharges of karst rivers and springs, and the method of limestone tablets. Within the geomorphology of karst, Gams was mostly dealing with the karst polje, especially its definition and evolution.

Two new freshwater fish species of the genus Telestes (Actinopterygii, Cyprinidae) from karst poljes in Eastern Herzegovina and Dubrovnik littoral (Bosnia and Herzegovina and Croatia)

Two new species, Telestes dabar and Telestes miloradi, are described on the basis of morphological comparisons of isolated geographical populations of fishes identified earlier as Telestes metohiensis. A lectotype is designated for Telestes metohiensis, whose range is shown to include waters of Gatačko, Cerničko, and Nevesinjsko poljes in Eastern Herzegovina. Telestes dabar from Dabarsko Polje (Eastern Herzegovina) and Telestes miloradi from Konavosko Polje (south Croatia) share with Telestes metohiensis the following combination of characters that distinguish them from the rest of the genus Telestes: pharyngeal teeth in one row, usually 5–4; preoperculo-mandibular canal not communicating with the infraorbital canal; mouth subterminal, the tip of the mouth cleft on or below the level of the ventral margin of the eye; postcleithrum minute or absent; ventral portion of the trunk with a dark stripe on a pale background; and dorsal portion of trunk uniformly dark and bordered ventrally by a dark midlateral stripe. Telestes dabar and Telestes miloradi are distinguishable from Telestes metohiensis in usually having 8½ branched dorsal-fin rays (vs. usually 7½), 9 or 10 gill rakers (vs. 7–10, usually 8), and the dark stripe on the ventral portion of the trunk below the main pigmented area of the back narrow and usually not reaching posteriorly to the caudal peduncle (vs. dark stripe wide and extending posteriorly to the caudal peduncle). Telestes dabar is distinguished from Telestes miloradi by having scales on most of the body situated close to one another and overlapping in a region behind the pectoral girdle and usually on the caudal peduncle (vs. overlapping scales on most of the body); the lateral line usually incomplete and interrupted, with 24–69, usually 54–65, total scales (vs. lateral line usually complete, with 55–67 total scales); scales above and below the lateral line slightly smaller than lateral-line scales (vs. of about equal size); head width 43–52% HL (vs. 48–58% HL); and lower jaw length 10–12% SL or 36–41% HL (vs. 8–10% SL or 33–38% HL). Telestes miloradi, a very local endemic species,is known only by historical samples. Telestes dabar is an abundant fish in Dabarsko Polje, but its range is critically restricted during the dry season by a few permanent sources. Nothing is known about its occurrence in underground karst waters.

Geomorphological specific features of Trebinje as tourist attraction

The municipality of Trebinje is located in the Trebišnjica river basin in the south of Bosnia and Herzegovina. Among Bileća, Ljubinje, Ravno, Herceg Novi, Dubrovnik and Nikšić a very specific and distinguishable karst countryside has developed which is made of karst polje in a debris, mountainous scope (Leotar, Bijela Gora, Zubačke mountains) and huge number of bare limestone hills and the surfaces with all micro shapes of holokarst. The author emphasizes the tourist attractions of the specific geomorphological shapes that can be valorized by the tourists in his works.

Impact of an inter‐basin water transfer and reservoir operation on a karst open streamflow hydrological regime: an example from the Dinaric karst (Croatia)

AbstractThis paper describes the hydrological changes caused by inter‐basin water transfer and the reservoir development on the hydrological regimes of two rivers. The Sabljaki Reservoir in the Zagorska Mrežnica River and the Bukovik Reservoir in the upper Dobra River began operation in 1959. Both are part of the hydroelectric power plant (HEPP) Gojak, whose installed capacity is 50 m3/s. Their water volumes at the spillway altitudes of 320·10 and 320·15 m a. s. l. are 3·3 × 106 and 0·24 × 106 m3 respectively. Both the Dobra and Mrežnica Rivers are losing, sinking and underground karst rivers. A 9376‐m‐long tunnel provides water from the Sabljaki Reservoir to the HEPP Gojak, which was constructed in the Lower Dobra River. The Sabljaki Reservoir is located in the Plaški karst polje, while the Bukovik Reservoir is located in the neighbouring Ogulin karst polje. The consequences of the inter‐basin water transfer are strong and have caused abrupt changes in the hydrological regimes of the downstream sections of both rivers. At the same time, the construction and development of both the reservoirs have also caused hydrological changes to the upstream section of the Upper Dobra River. Copyright © 2010 John Wiley & Sons, Ltd.

Water temperature as a natural tracer – a case study of the Malenščica karst spring (SW Slovenia)

For the adequate protection of karst springs it is important to understand the functioning of karst systems in their recharge areas. Besides tracer tests with artificial tracers, tracings with natural tracers, such as temperature, are a very useful research tool, especially in complex karst systems with various types and sources of recharge. Detailed monitoring of water levels and temperatures of the Malenščica karst spring, as well as of the intermittent Cerknica Lake and Kotliči spring in its recharge area, indicated that temperature is a good tracer in winter and summer periods, especially when the Cerknica karst polje is flooded. High or low air temperatures influence the temperature of water, which sinks at the Cerknica polje and flows rapidly through karst channels toward the springs. Detailed analysis of selected events enabled calculation of the velocity of groundwater flow toward the Malenščica spring under different hydrological conditions. The estimated values are in accordance with the velocities previously defined in this area, based on several tracer tests with artifi cial tracers. From the results, it is possible to assess the transport velocities of contaminants under different hydrological conditions. This is important information for the protection of the Malenščica spring, which is captured for the public water supply.

Extreme hydrological events in karst areas of Slovenia, the case of the Unica River basin

The study presents natural hazards in Slovenia's karst, focusing on flooding in karst poljes. A specific study was done on the flood dynamics of two typical and connected karst poljes (Cerknica and Planina) of the Classical Karst region. In the case of particularly extreme hydrological conditions in the autumn of 2008, detailed analyses of the recharge-discharge regime and the interrelationship of flooding on the two poljes were done. Daily precipitation, discharge, and water level values from several monitoring sites were analyzed and cross-correlated, and additional hydrological analyses were done using a digital elevation model in order to acquire water level increase and decrease intensity, flood water volumes, and the extent of flooding and to understand the conditions controlling karst flooding. The results reveal that the hydrological functioning of the studied karst poljes is influenced by the hydrogeological and temporary hydrological conditions in the catchment area. The response of the binary karst system (i.e., the influence of autogenic and allogenic recharge) is especially distinct. The study shows that during extremely intense recharge, the reactions of karst aquifer systems to precipitation are as rapid as the response of surface waters (the water level of Cerknica Lake increased with an intensity of 38-63 cm/day or 55 m3/s respectively) while retention capacities are negligible. In contrast to flash floods, floods in karst areas may last from several weeks to several months. For the observed period a three-dimensional simulation of the flooding was made. At the maximum recorded water level, the volume of water on the Cerknica polje was 51 million m3, and 26 million m3 on the Planina polje. The maximum extent of flooding on the Cerknica polje was 23 km2 and on the Planina polje 9.5 km2. On the basis of the study, information was provided regarding future hazard mitigation. However, the study demonstrated that a sufficiently dense monitoring network is necessary to predict the occurrence and duration of floods with greater certainty.

Environmental characterization of a karst polje: an example from Izeh polje, southwest Iran

Groundwater contamination is a well-known phenomenon, which occurs on local and regional scales in Izeh polje. The aims of this paper are investigation of the impact of human activities on the polje ecosystem, determination of the vulnerability of ground water, and to solve environmental problems. Nitrate contamination of groundwater in the Izeh polje was predicted using a solute transport model. The nitrate concentration in groundwater in most parts of Izeh polje is greater than maximum concentration permissible for drinking water, i.e., 45 mg/l. The main source of nitrate in the eastern underground areas of Izeh city is the domestic sewage. Bacterial pollution of shallow ground water in Izeh polje is severe and widespread. About 45% of ground water samples in May and September 2001 have positive MPN coliforms. Infiltration of polluted surface waters and decrease of water table depth, have lead to bacterial pollution of 80% of ground water samples in January 2002. The northeast, south and southwest areas of Izeh polje have higher pollution potential rather than its middle parts. The aquifer vulnerability indices in the middle, eastern, and northern parts of the polje are moderately lower as a result of decreased sediment size of the aquifer. The pollution in the polje depends on the amount and presence of pollutants. If they do exist, the possibility of pollution is considerable due to the coarseness of materials and shallow depth of groundwater table.

Influence of sea-water intrusion and agricultural production on the Blato Aquifer, Island of Korčula, Croatia

The Blato aquifer is situated on the western side of the island of Korcula, southern Dalmatia, Croatia. The terrain is built of karstified carbonate rocks, mostly of the Cretaceous age. In the Blatsko karst polje there are four water supply wells with a total yield of about 60 l/s. The catchment area is 28 km2. The whole terrain is tectonically disturbed and compressed; the most permeable fracture system is perpendicular to the structural “b” axes, which gives rise to a general groundwater direction towards the island’s northern coast. Average precipitation is 850 mm/year, but when there is less than 700 mm/year there is a high possibility of sea-water intrusion during the summer season. The risk significantly increases when dry years repeat. Hydrochemical research has shown that two main pollution sources occur at different hydrological moments: sea-water intrusion happens in the dry summer period when there is maximal extraction and almost no recharge; and the washing of nitrates and other humanly caused pollution indicators from the soil and epikarst belt during the rainy season. All factors must be taken into account when planning management and protection of such a sensitive environment.

Relief evolution in the hinterland of the Pivka river

The article discusses relief evolution in the catchment area of the highest situated permanent spring of the Pivka river – the Pivšce karst spring near the village Zagorje. The discussed landscape, which lies on the southernmost edge of the Upper Pivka valley, shows several geomorphological particularities, which are the result of different geomorphogenetic processes in the past. The basic characteristics of the present relief were shaped in the Pliocene when also the original valley of the Pivka river was formed. The region was more profoundly transformed by Pleistocene processes, which strongly altered the surface. Apart from karstic relief forms, there are several small dry stream channels on the land surface, which were carved by torrents. The two most distinctive relief features are the karst polje situated between the villages Koritnice, Bač and Knežak, which is covered with rubble and gravel-like clastic sediments, and the dry valley of the former Pivka river lying southwest from Koritnice.

Baltazar Hacquet (1739/40-1815), the Pioneer of Karst Geomorphologists

Besides other sciences, B. Hacquet dedicated his research to geology and geomorphology (as we call them now). His most important work “Oryctographia carniolica or Physical (= geological) description of Carniola...” (1778−1789) contains descriptions of rocks, ores, fossils, as well as surface and underground features. In Carniola, karst is prevailing and therefore there is a lengthy description of karst geology and geomorphology included. His classification of mountains specially mentions Montes secundarii formed by grey limestone. Of surface features dolines, glacio-karstic dolines on high plateaus (with temperature and vegetation inversion), and karst poljes are mentioned. Hacquet presumed the evolution from flooded polje (seasonal lake) to a dry one. To explain the weathering and dissolution of limestone Hacquet took into account the differences between the rock, the exposition and its element content. That is the reason why Gams regarded him as a precursor of a climatic geomorphology and the “father” of corrosion theory. Hacquet has also found the difference between limestone and dolomite. His description of dolomite as Lapis suillus preceded the one of D. Dolomieu for 13 years. Hacquet’s statements were not based on observation only, but on the experiment too. When looking upon Hacquet’s explanations and results we must not forget that Hacquet’s time was still time of parapathetic logic, of four elements and of the principle of burning - the flogiston.

Hydrogeological characteristics of some deep siphonal springs in Serbia and Montenegro karst

In terms of hydrogeological, engineering-geological, and hydrotechnical tapping in karst in relation to ground waters, karst channels, springs and ponors, speleodiving is the only research method which enables direct observation, studying and exact geological mapping of karst channels and caverns. Data collected during speleodiving research contribute considerably to the analysis of karst evolution process in the given region, which is very important in evaluating the depth of karstification and determining the main direction of the groundwater flow. In the past 30 years in Serbia and Montenegro, speleodivers have investigated over 40 siphonal springs, active cave channels and ponors, of which more than 20 are proof of deep siphonal circulation in karstic aquifers. The karstic springs are the most interesting phenomenon from a hydrogeological view point, and their investigations need particular attention. Most of significant karstic springs are on the rims of erosion basins—perimeters of karst poljes, river valleys, sea coasts and contact areas between karst aquifers and hydrogeological barriers. General characteristics of the spring regime are the direct correlation between precipitation and spring discharge. Moreover, the hydrogeological regime of these springs also depends on the size of the catchment area, karstic aquifer retardation capacity, total porosity, as well as lithological and structural characteristics.

Flooding in the area of Knežak, Bač and Koritnice in November 2000

In November 2000 a flood occurred in karst polje between the settlements Bač, Knežak and Koritnice in the municipality of Ilirska Bistrica. The continuous surface of the flood extended to 59 hectares. The flood mostly affected Bač, where 23 residential and some other buildings, an industrial facility and road infrastructure suffered damage.