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The width and depth of the main channels were measured along the length
of seven rinnenkarren systems on the floor of the glacier valley under
the Tragl peak in the Totes Gebirge, Austria. The cross-section areas of
the channels were calculated which were considered in relation to the
distances between their location along the flow path and the mar...
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... width and depth of the main channels of seven rinnenkarren systems were measured for every 10 cm. The width and depth of tributary channels were also measured for every metre, in some cases for every 10 cm (Fig. 2a). The investigated rinnenkarren systems are at the south end of the glacier valley (Totes Gebirge) that is under the Tragl-peak. The floor is dissected by cuestas (karstic cuestas are called schichttreppenkarst, Bögli, 1980). The rinnenkarren systems are located on the bedding plane of the cuestas (Fig. ...
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... cross-sectional areas of the main channels and of some tributary channels were calculated for every 10 cm (Fig. ...
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... T cross-section areas were represented as a function of the distance, measured from the upper margin of the slope (upper margin of the catchment area). The exact location of the widest cross-sections was registered (Fig. ...
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... i l i is the entire length of a tributary channel and all its tributaries and Δd is the distance measured along the main channel between two adjacent tributary channels (Fig. ...
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... measured the ampleness and amplitude of the local hollowings of the channels. Ampleness is the length of the widening. Amplitude is the greatest value of the cross-section (Fig. ...
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... small hollowings on such channels, so the frequency of the hollowings is high, Fig. 11). On the rivulets of these channels more turbulence of small extension develops. b. The number of hollowings on the channels is small, but their ampleness is large (there are a few large hollowings on such channels, so the frequency of the hollowings is low, Fig. 12). On the rivulets of these channels few turbulent zones with larger extension ...
Citations
... As a result, similar patterns on the icy surfaces of other Solar System bodies have been interpreted as penitentes, such as the Bladed Terrain Deposit of Pluto's Tartarus Dorsa region [8,37]. It has been suggested that penitentes as high as 15 m may exist on Europa's surface [38], although the resolution of currently available images of Europa's surface is insufficient to verify this, but this hypothesis is debated [47,48]. Credits: A. S. Maloney, CC BY-SA 3.0 license. ...
... In that case, the limestone substrate is rigid and not very porous. One of the most intriguing sharp-edged landscapes formed by rock dissolution are limestone forests, found at tropical locations such as in the western part of Madagascar in the area called Tsingy [47,52], in Malaysia [53] or in south China [54]. Spectacular sharp and vertical pinnacles, tens of meters high, rise from the surface of a horizontal Karst plateau (Figure 1(b)). ...
... Meanderkarren are Rinnenkarren with meanders. The flow dynamics of water channelized in Rinnenkarren systems have been studied on the field and in laboratory reproduction with non soluble materials [47]. ...
... Rinnenkarren are closed downhill arheic channels of dissolution origin, developed by rivulets (Figure 1, Sweeting, 1973;Trudgill, 1985;White, 1988;Hutchinson, 1996;Ford & Williams 2007;Veress, 2010). The channel systems (Horton-type channels, Ford & Williams, 1989, 2007 consist of a large main channel (often up to 30-50 m long) and joining smaller-sized tributary channels (Veress et al., 2013(Veress et al., , 2015a. Their widths and depths are a few decimeters at the most. ...
... However, the increase in channel cross-section of the main channel can also occur locally at the tributary channel junctions (local hollowing), along short sections (≈0.3-1 m, Veress et al., 2013). Kamenitzas with various morphologies (Veress, 2010) often appear in these places as well, which may be connected here to several tributary channels. ...
... Kamenitzas with various morphologies (Veress, 2010) often appear in these places as well, which may be connected here to several tributary channels. The origin of local hollowing is attributed to flow with emerged vorticity at the junctions (Veress et al., 2013). The vorticity at the site of the junctions was confirmed by laboratory model experiments (Deák et al., 2012). ...
The development of emerging hollowing parts of the main channels of rinnenkarren systems at tributary channel junctions is interpreted in this study using Computational Fluid Dynamics (CFD) simulation. In the field, data from cross-sections of 505 local hollowings with one or more tributary channel junctions were investigated. The shift in the width–depth ratio of the local hollowings was studied as the number of junctions and the size of the hollowing changed. Flow was simulated through CFD in digital model channels, and the nature of the resulting vorticity was interpreted. Field data show that local hollowings emerging in the main channels of the channel systems at the junctions. In the main channels, when only a few tributary channels join in the vicinity of each other, local hollowings deepen during their growth and, most often, gradually become pits (depth is larger than width), as the morphometric analysis suggests. As the number of tributary channels increases, the local hollowing may develop into a kamenitza (width is larger than depth). The model experiment suggests the explanation that more tributary channel junctions result in more extensive vorticity, which contributes to the lateral extension (widening) of this channel section. The distance of the tributary junctions from each other also influences the downstream dimension of the local hollowing. In the field, the larger this distance, the more separated the local hollowings induced by individual tributaries. The model experiment suggests that this may occur because the intense vorticity generated by individual junctions becomes increasingly sectionalized as the tributary channel density decreases.
... They observe how the plant behaves in response to various factors such as pests, herbicides, and different weather conditions. Additionally, they assess the yield and product quality to determine the potential of the genetically modified plant for future commercial cultivation (Veress et al. 2013). ...
Enhancing the resilience of plants to abiotic stresses, such as drought, salinity, heat, and cold, is crucial for ensuring global food security challenge in the context of climate change. The adverse effects of climate change, characterized by rising temperatures, shifting rainfall patterns, and increased frequency of extreme weather events, pose significant threats to agricultural systems worldwide. Genetic modification strategies offer promising approaches to develop crops with improved abiotic stress tolerance. This review article provides a comprehensive overview of various genetic modification techniques employed to enhance plant resilience. These strategies include the introduction of stress-responsive genes, transcription factors, and regulatory elements to enhance stress signaling pathways. Additionally, the manipulation of hormone signaling pathways, osmoprotectant accumulation, and antioxidant defense mechanisms is discussed. The use of genome editing tools, such as CRISPR-Cas9, for precise modification of target genes related to stress tolerance is also explored. Furthermore, the challenges and future prospects of genetic modification for abiotic stress tolerance are highlighted. Understanding and harnessing the potential of genetic modification strategies can contribute to the development of resilient crop varieties capable of withstanding adverse environmental conditions caused by climate change, thereby ensuring sustainable agricultural productivity and food security.
... Channels are complex features. On their floor, kamenitzas, pipes, small basins, hollows, karren sinkholes, karren terraces and steps may occur, while on their side walls, scallops and rillenkarren may occur [3,15,17,21,22] . Several varieties can be distinguished, such as rundkarren, Hortonian type channels, decantation runnels, simple and complex channels and type A and type B channels [2,3,15,23] . ...
... On some parts of the main channel, the width increases locally and channel hollows develop. The channel hollows develop because the water flowing from the tributary channel triggers vorticity which causes the local increase of dissolution [22] . Apart from channel hollows, it often occurs that the channels widen from their upper end towards their lower end (Figure 1). ...
... The development of the channel hollows of the main channels is caused by the tributary channels. The rivulet of the tributary channel conjoining the rivulet of the main channel causes turbulence which increases dissolution locally [22] . Vortexes are larger, and turbulence is more intensive and thus, dissolution is larger where the tributary channels are hanging over the floor of the main channel. ...
In this study, the development of rinnenkarren systems is analyzed. During the field studies, 36 rinnenkarren systems were investigated. The width and depth were measured at every 10 cm on the main channels and then shape was calculated to these places (the quotient of channel width and depth). Water flow was performed on artificial rinnenkarren system. A relation was looked for between the density of tributary channels and the average shape of the main channel, between the distance of tributary channels from each other and the shape of a given place of the main channel. The density and total length of the tributary channels on the lower and upper sections of the main channels being narrow at their lower end (11 pieces) and being wide at their lower end (10 pieces) of the rinnenkarren systems were calculated as well as their average proportional distance from the lower end of the main channel. The number of channel hollows was determined on the lower and upper sections of these main channels. It can be stated that the average shape of the main channel calculated to its total length depends on the density of the tributary channels and on the distance of tributary channels from each other. The main channel shape is smaller if less water flows on the floor for a long time because of the small density of the tributary channels and the great distance between the tributary channels. In this case, the channel deepens, but it does not widen. The width of the main channel depends on the number and location of the rivulets developing on channel-free relief. The main channel becomes narrow towards its lower end if the tributary rivulets are denser and longer on the upper part of the main rivulet developing on the channel-free, plain terrain and their distance is larger compared to the lower end. The channel hollows develop mainly at those places where the later developing tributary channels are hanging above the floor of the main channel. Thus, the former ones are younger than the latter ones. It can be stated that the morphology of the main channels (shape, channel hollows, and width changes of the main channel) is determined by the tributary channels (their number, location and age).
... The relation between the number of rivulets and the angle of the bearing slope (slope length 1 m) created in laboratory was also investigated. During the research of karst phenomena, laboratory experiments have often been employed (Curl, 1966;Pluhar and Ford, 1970;Quinif, 1973;Slabe, 1995;Veress et al., 1998Veress et al., , 2013Perne and Gabrovšek, 2009). Glew and Ford (1980) made an experiment similar to ours: they studied the relation between the number of rillenkarren that was created as a result of artificial rain on gypsum plates at different slope angles. ...
The relation between the inclination and the quality of the bearing slope, and the channel type and channel density of various rinnenkarren (type A and type B channels) was investigated. On the bare karren slopes of Totes Gebirge, the connection between the densities of type A and type B (type A channels have no tributary channels, and they are smaller; type B channels have tributary channels, and they are larger) channels and the slope angle was studied, while in laboratory the relation between the number of rivulets forming the channels and the slope angle and the quality of slope was analysed. The density of type A channels increases with the increase in the slope angle, while that of type B channels decreases. In the laboratory the number of rivulets on the various parts of the slope was studied on glass, gypsum and metal plates between 5 and 50° (as well as on metal plate between 1 and 70°). The dip angle of the bearing slope was modified every 5°. The number of rivulets increases with the slope angle mainly on the upper part of the slope and on the metal plate. The number of rivulets decreases towards the lower part of the slope in the case of the same slope and the same slope angle. The number of rivulets (and thus the number of channels) depends on the speed of water flow and the roughness of the surface. On a slope with a small dip angle (smaller than 20°), few rivulets and channels develop and, thus, rinnenkarren systems with large catchment areas may form whose main channels develop into large, type B channels. On slopes with a large dip angle (greater than 30°), numerous rivulets develop even at the beginning of channel development. Because of large rivulet density, channels with small catchment area and thus small-sized (type A) channels may develop. On the karren slopes, two models of channel development are possible: according to model 1, on slopes with a continuously smaller dip angle, the beginning of channel development is increasingly different, thus rinnenkarren systems form which are built by main and tributary channels. In the case of an increasing slope angle, this tendency is less and less valid. On slopes with an increasingly larger slope angle, the beginning of channel development will not be different. According to model 2 (based on the laboratory model), the rivulets that developed on the upper part of the slope join on the lower part of the slope. In this case the initiation of channel formation of the main and tributary channels of the rinnenkarren systems is similar. On the bare slopes of Totes Gebirge, model 1 can be regarded as the dominant one.
This study deals with the karren formation of bare surfaces. The used methods are theoretical calculations, field mapping, laboratory experiments, and digital modelling. The denudation rate of karren surfaces on bare slopes and based on the data of measurements, the denudation rate of karren in different vegetation belts were given. Mostly, the development of rinnenkarren and meanderkarren was analysed. A function relation was determined between the density of rinnenkarren types and the slope angle. The effect of the main channel and tributary channels on each other was studied by computer modelling. The impact of the wind on the development of karren and the conditions for the development of tropical karren was also investigated.
The goal of this study is to interpret the cross-sectional increases of rinnenkarren systems with the use of analytical model and CFD simulation. In rinnenkarren, water accumulation from the catchment was approximated using an analytical method based on field data. The length of eddies appearing at tributary junctions was studied by CFD in model channels. The results of the analytical and numerical models were compared against morphometrical parameters of rinnenkarren surveyed in the Totes Gebirge (Austria). It is found that there is a relationship between catchment size and channel development. Along small catchments, channel development is random. However, channel development along large catchments is controlled by water concentration. Decrease in the slope angle of the catchment results in an increase in the volume of water entering the channel and development of tributary channels. When water inflow is not concentrated in a single place, several smaller tributary channels emerge. When it is concentrated, only one large-sized and long tributary develops. At the junctions of large tributaries significant vorticity was identified in the CFD models. In addition to the previous model studies, the similarity between the lengths of the simulated vorticity sections and the local field hollowings was revealed.
In Hungary, geographical publications already mentioned special karst objects more than half a thousand years ago. About 250 years ago, some authors explicitly dealt with limestone mountains including their spectacular large cave entrances and their famous gorges. The caves of Hungary are widely known in the world based on their natural, cultural and historical values as well as their role in scientific research, despite the fact that there are no Hungarian caves among the longest or deepest caves in the world. In many cases, the hypogenic caves in Hungary served as study areas even for foreign researchers. The “Bükk Culture” is an internationally acknowledged denomination for a prehistoric culture named after the artefacts found in the caves of the Bükk Mountains. Likewise, the Middle Pliocene "Estramontinum" vertebrate biostratigraphic stage refers to the exploration site at Esztramos Hill. The work of Hungarian cave researchers contributed to solving the problems of several special karstic phenomena (e.g. the formation of helictites, the effect of tidal phenomena on the discharge of karst springs). Furthermore, the contribution of Hungarian cave researchers was also important in establishing new scientific fields (e.g. biospeleology) or raising them to an international level (e.g. speleotherapy). Our oldest-known, best-researched cave system is Baradla, which is one of the longest dripstone caves in the temperate zone with an active stream, and one of the earliest tourist caves in the world. In the nineteenth century, it was recorded as the second-longest cave in the world after Mammoth Cave (USA). The international reputation of our researchers and the universal value of our caves are proved by the fact that Hungary hosted the 10th International Speleological World Congress in 1989, and the caves of Aggtelek Karst (together with Slovak Karst) are the only objects listed in the Natural Category of World Heritage sites in Hungary.KeywordsSurface karst phenomena and landformsArchaeological findingsCave explorationCave mappingCave protection
The leading role of dissolution and the dominant subsurface drainage determine the special idiosyncrasy of karst geomorphology, with some notable variations depending on the type of soluble rock. The formation of karren is essentially related to the uneven or differential dissolution of the bedrock surface controlled by a number of factors, resulting in the development of depressions, clefts, channels, tubes, protruding features, and irregular patterns. Sinkholes or dolines are enclosed depressions with internal drainage widely regarded as one of the most characteristic landforms of karst landscapes. They are typically circular to subcircular in plan and show wide morphological diversity (cylindrical‐, conical‐, bowl‐, and pan‐shaped). In some cases, the variable geometry of the sinkholes can indicate different evolutionary stages and the relative age of the depressions. In nature, a complete spectrum between suffosion, collapse, and sagging sinkholes can be found in covered karst settings.
The term karst refers to specific geomorphological processes and thereof resulting in characteristic landscapes. About one-fifth of Austria consists of lithologies—mainly limestone, dolomite, and marble—susceptible to dissolution (i.e. karstification). Those lithologies occur in every landscape including the complete range of altitude: Northern Calcareous Alps, Southern Calcareous Alps, Helvetic units, Central Eastern Alps, Bohemian Massif, Alpine forelands, and Neogene basins. Consequently, Austrian karst landscapes are also subjected to a suite of non-karstic geomorphological processes, resulting in a great variety of endo- and exokarst features with distinct modifications. Small-scale solution features (karren) and dolines are very common. At high altitudes, these features have been exposed to processes related to Pleistocene glaciations. Moreover, karst springs with high discharge variabilities are well-known hydrologic features. Austria hosts 18,100 caves, and some of them are amongst the longest and deepest in the world. Although the majority of the caves are of epigenetic origin, some caves are also related to hypogene speleogenesis. Imprints from human activities on the karst environment can be traced back to the Palaeolithic period. Today, human-karst interactions are of particular importance: karst aquifers provide the catchment areas for drinking water supply for several municipals and karst landscapes represent resources for tourism, recreation, and furthermore. Not least, research in karst and caves makes an important contribution to science (e.g. palaeoclimatology).KeywordsKarstKarst landscape typesDistribution of karst areasSurface karst featuresCavesHuman-karst interaction
