Regeneration process of the karst water springs in Transdanubian Mountains, Hungary 247 Hungarian Geographical Bulletin 62 (3) (2013) 247–265. Regeneration process of the karst water springs in Transdanubian Mountains, Hungary Krisztina BABÁK1, Ibolya KISS2, Zsanett KOPECSKÓ3, István Péter KOVÁCS4 and Ferenc SCHWEITZER5 Abstract Since the 1940s and 50s, there have been several researches dealing with karst water springs and the mapping of the continuous karst water level of the Transdanubian Mountains. The karst water level sank because of the intense bauxite and coal mining between the 1950s and 1980s and it started to increase aft er the decrease of mining activity. However, only a few au- thors investigated and modelled the water level changes and the rejuvenation of karst springs in the karst reservoir. Our paper is about the mineral contents and geomorphic properties of karst water springs near a chosen reservoir and our aim was to get some information about the regeneration process of the karst water reservoir. The geomorphic properties of karst water springs were mapped, using detailed fi eld survey (DGPS) and geomorphic mapping. The mineral contents of spring waters were analysed to prove their origin. GIS results show that the karst water level in the karst reservoir reached 180–190 m a.s.l. Keywords:, karst water spring, karst water level, mineral contents, geomorphological mapping, Transdanubian Mountains Introduction The term of karst water stems from Grund, A. (1903) who applied it to karst wa- ter accumulated in the holes of dolomite and limestone mountains (Schréter, 1 Institute of Geography, University of Pécs, 7624 Pécs Ifj úság u. 6. E-mail: babak@gamma.tt k.pte.hu 2 Institute of Chemistry, University of Pécs, 7624 Pécs Ifj úság u. 6. E-mail: kissi@gamma.tt k.pte.hu 3 Doctoral School of Earth Sciences, University of Pécs, 7624 Pécs Ifj úság u. 6. E-mail: zsanett @gamma.tt k.pte.hu 4 Institute of Geography, University of Pécs, 7624 Pécs Ifj úság str. 6. E-mail: vonbock@gamma.tt k.pte.hu 5 Geographical Institute Research Centre for Astronomy and Earth Sciences, HAS, 1112 Budapest, Budaörsi út 45. E-mail: schweitzer.ferenc@csfk .mta.hu 248 Z. 1940). Höfer, H. (1912) classifi es the subsurface waters of the karst areas as the subset of rock-moving waters (Felswasser), cave waters (Höhlenwasser) called Triassic water by the Hungarian mining engineer Szádeczky-Kardoss, E. (1941) who used this term, too. According to Kállai, G. (1927), the term mentioned above can be thanked to Jex, S. who was a former mining director in Tatabánya and who fi rst applied the term Triassic water to vadose water streaming in the Triassic limestone bed. In the respect of karst water research dealing with karst phe- nomenon, the work of Cvij ič, J. (1893) is also worth mentioning. At the beginning of the 1940s heated discussion evolved among the Hungarian and the foreign hydrologists about the continuous interconnected karst water level of karst water reservoir of Transdanubian Mountains. The theory of Katzer, F. (1909) was accepted by some researchers (Höfer, H. 1912; Keilhack, K. 1912; Lehmann, O. 1932) who believed that continuous karst water level can be observed very rarely and their regular distribution of karst water is more frequent (Schréter, Z. 1940). In contrast, others adopted the continuous interconnected karst water level theory by Grund, A. (1903) to the area of mountains (Schréter Z. 1940). Grund (1903) suggested a continuous interconnected karst water level in the limestone of the karst region in a way which able the accumulated, mus- tered waters to run on and communicate with each other in every direction in the fracture network of limestone mountain hereby the continuous subsurface water level evolves similarly to the phreatic water. According to the opinion of Szádeczky-Kardoss, E. (1948), the theory of Grund can be accepted in case of deeper karst (for example Transdanubian Mountains) while in case of shal- lower karst, the theory of Katzer can be applied. Szádeczky-Kardoss started his research to create the fi rst Hungarian karst water map on the South part of the Transdanubian Mountains in the sec- ond half of the 1930s. He determined that the karst water level stands out well at 109–146 m a.s.l. in the area of Keszthely Mountains, below that height, water abundance and above that height, a shortage of water can be experienced. The theory of the continuous interconnected karst water reservoir was accepted around the 1940s and 1950s (Szádeczky-Kardoss, E. 1941, 1948) which is due to the hydrogeological researches related to the bauxite and coal mining below the karst water level. At the same time the karst water level maps were illustrated with izohypses were born concerning the area of the surface karst water level and its wider environment (Szádeczky-Kardoss, E. 1941, 1948). Alföldi, L. (2007) put the modern knowledge of the geological and hydrogeological background of the karst water reservoir into a unifi ed framework. Aft er World War II the increased industrialisation demanded more and more raw materials, but that demand couldn’t be satisfi ed with surface 249 and near surface mines because of their depletion, which aff ected deep min- ing endangering the subsurface and karst water inrush. It went hand in hand with the active and later the passive anhydrous of the mine tunnels. Later its amount – Csepregi, A. (2007) calculated (estimated) an amount of 10 billion m3 exploited karst water between 1951 and 1990 – exceeded the average amount of 500 m3/s infi ltration being necessary for the natural regeneration of the karst water reservoir (Csepregi, A. 2007). The water removals on spots or in smaller areas had an impact on the whole area because of the connected water level in the Széki Reservoir (3 km NW from Ajka). Apart from some exceptions, almost all karst springs of the Transdanubian Mountains have dried up or their yields have decreased signifi cantly (Figure 1). Since the 1990s, the karst water level has begun to rise (Figure 2) as a result of mine closures and the dewatering works, however, at the beginning, very diff erent and oft en exaggerated calculations related to the entire period of the regeneration of the reservoir emerged. According to the latest model calculations, the almost total refi ll of the reservoir can be expected by mid- or second half of the 2020s (Csepregi, A. 2007). On 4th October 2010, while examining the possibilities of the dewatering of the reservoir of MAL Zrt. (Hungarian Aluminium Corporation), following its tailings Fig. 1. Karst water level in 1990 comparing to the original karst reservoir conditions (based on Csepregi, A. 2007). – 1 = bauxite mine; 2 = coal mine; 3 = manganese mine; 4 = relative karst water level; 5 = border of the karst water reservoir Fig. 2. Karst water level in 2006 comparing to the original karst reservoir conditions (based on Csepregi, A. 2007). – 1 = bauxite mine; 2 = closed bauxite mine; 3 = closed coal mine; 4 = closed manganese mine; 5 = relative karst water level; 6 = border of the karst water reservoir 250 rupture, sludge disaster (Schweitzer, F. 2010), we noticed intensive spring works on the surface around the Széki Reservoir (Schweitzer, F. and Viczián, I. 2011). Investigating the causes of the sludge disaster, the engineer report (Mecsi, J. 2012; Turi, D. et al. 2013) highlighted the role of ground water in the disaster which can be closely related to the recovery of the resources tapping the increasingly restored karst water. The aim of our study is to identify the sources, the origin of spring water found near the Széki Reservoir in 2010 and their relationship with the karst water reservoir. Besides, as a subgoal, we will defi ne the source areas and the sketching of their geomorphological situation. Site description Our investigation area is situated in Pápai-Bakonyalja physical geographical mi- croregion, in the valley of Csigere Creek (Figure 3). From the geomorphic point of view, it covers the lower, Southwestern part of the hillslope of the Bakony Fig. 3. Sketch of the investigated area. – 1 = water reservoir; 2 = water course; 3 = sludge reservoir; 4 = residential area; 5 = primary road; 6 = secondary road; 7 = tertiary road; 8 = railroad; A, B, C = detailed sketches (See Figs 4–7) 251 Mountains (Dövényi, Z. ed. 2010). The higher parts of the Bakony Mountains in the East and the lower Quaternary alluvial fan system in the West are connected by the Csigere Creek Valley. Detailed fi eld mapping was done West and Southwest from the Széki Reservoir created by the dam construction at the Csigere Creek. The area is built up from up to 1,000 m thick Cretaceous calcareous sediments covered by 250 m thick clay, conglomerate, marl and limestone lay- ers of Eocene transgression (Bohn, P. 1983). The bedrock in the areas North and Northwest from the reservoir contains the Eocene limestone layers. Thick lay- ers of Oligocene and Miocene conglomerates are superimposed on limestone, they cover the surface in the Western part of the reservoir. Methods Detailed geomorphic mapping based on 1:10,000 scale topographic and or- thophoto maps published in 2005 was done to clear the position and the geo- morphic properties of karst springs and their surroundings. The 2.5 m vertical resolution of the topographical map and the vegetation cover on the ortho- photo map impeded the identifi cation of the exact altitudinal and horizontal positions of karst springs. Hence, karst springs and their surroundings were surveyed by Topcon FC-250 diff erential GPS (DGPS). The survey was hindered by the dense vegetation, accordingly, the accuracy of the measurements was maximum 50 cm (horizontal) and 20 cm (vertical). The unequivocally identi- fi ed karst spring outlets were measured more precisely, with subcentimeter accuracy. The surveyed data were processed with Grass GIS 6.4.2., Qgis 1.6.0. and Inkscape 0.48 was used to draw the detailed geomorphic sketch. The height values of karst spring outlets were compared to the “origi- nal” (before the 1950s) karst water level of the izohypse maps (Jaskó, S. 1959; Csepregi, A. 2007) to identify the karstic origin of the springs. The izohypses were digitised using v.digit module of Grass GIS 6.4.2. and they were inter- polated with v.surf.rst module using spline interpolation (Mitasova, H. et al. 2005) and 100 m horizontal resolution was applied. The DEM of the “origi- nal” karst water level was smoothed using 33×33 convolution matrix and an averaging technique. r.resap was used to increase the horizontal resolution of the DEM of karst water level to 10 m. The DEM of the „original” karst water level was compared to the DEM of the land surface using r.mapcalculator. The map clearly shows the place where the „original” karst water level crosses the surface and it also demonstrates if the areas are under karst water pressure or not. The mineral content of water samples taken from springs were analysed to clear their origin. Results were compared to the mineral contents of karst waters published by former authors. 1.5 litre spring waters were sampled from springs 3 times during the observation period (Figures 4 and 5). 252 As a result of the environmental analyses, mostly very low concen- trations of materials were established. The results of the measurements are usually expressed in the unit of "gram per litre," (g/l). Water analyses can be done by several methods. The most common and oldest type of measurement is titration. Instrumental methods are becoming more and more popular. Our measurements were made according to the Hungarian Standards (MSz). Titration depends on using a well-defi ned chemical reaction to measure the amount of a standard solution needed to react with a defi ned amount of the sample. A known volume of sample is placed into a beaker and the standard reagent is dispensed from a burett e to the sample (thus the volume of stand- ard reagent can be measured). The "endpoint" of the reaction is determined by observing the colour change using an indicator or by observing the physical- chemical change in the solution using an instrument. Knowing the amount of the standard reagent, the amount of the analysis can be calculated in the sample. Fig. 4. Geomorphic sketch of the karst spring area, NW from the Széki Reservoir (area ‘A’ inside Fig. 3). – 1 = hillslope; 2 = fl ood plain; 3 = waterlogged surface pach; 4 = slope; 5 = high bluff ; 6 = travertine with overhanging slope; 7 = dry valley; 8 = ephemeral channel; 9 = water reservoir; 10 = channel; 11 = oxbow lake; 12 = artifi cial lake; 13 = unpaved road; 14 = dam; 15 = bridge; 16 = waterfl ow direction (in the channel); 17 = water fl ow direction (on waterlogged area); 18 = karst springs 253 Alkalinity is a measure of water’s ability to neutralize acids. Bicarbonate, carbonate and hydroxide ions are the most common causes of alkalinity. The alkalinity of water is determined by end-point titration with a strong acid solu- tion (HCl). Titration to pH 8.3 (decolourisation of phenolphthalein indicator) will indicate the complete neutralization of OH- and half of CO3 2- while titra- tion to pH 4.5 (sharp change from yellow to orange of methyl orange indicator) will indicate total alkalinity {MSz 448-11 and ISO 9963-1}. Hardness is determined by the concentration of cations, Ca2+ and Mg2+ are common cations in hard water. The water runs through the rocks containing min- erals such as gypsum (CaSO4 • 2H2O), calcite (CaCO3), dolomite (CaMg(CO3)2). Temporary or bicarbonate hardness is caused by the presence of dissolved bicarbonates of calcium, magnesium and other heavy metals. It’s determined by end point titration with a strong acid solution (HCl) using methyl orange as indicator {MSZ 448-21}. Ca2+ and Mg2+ can be combined with chlorides and Fig. 5. Geomorphic sketch of the karst spring area, W from the Széki Reservoir (area ‘B’ inside Fig. 3). 1 = hillslope; 2 = fl ood plain; 3 = slope; 4 = dry valley; 5 = water reservoir; 6 = water course; 7 = spring; 8 = unpaved road; 9 = primary road; 10 = bridge; 11 = quarry 254 sulphates resulting in permanent hardness of water which can't be removed by boiling. The permanent hardness of water is determined by complexometric titration using EDTA (ethylene-diamine-tetraacetic acid) at pH 10 (both Ca2+ and Mg2+ will complex with EDTA at that pH value) {MSZ 448-3 and MSZ 448-21}. Standard laboratory glasware such as burett es, volumetric fl asks and beakers [Beakers (100 ml), Burett e (25 ml), Graduated cylinder or pipett e (100 ml), Whatman fi lters (only for suspended materials)] were used during the analysis. Results The geomorphic position of karst springs The construction of the ~10 m high dam of Széki Reservoir at the Csigere Creek was fi nished in 1978 and it also involved the channel regulation of the creek. The outfl ow water leaves the dam and fl ows in an artifi cial, 4 m wide channel towards west (Figure 4). The channel bisects the former, 70–90 m wide alluvial fl at of Csigere Creek which cut a 7–10 m deep valley into the sediments on the hillslope of Bakony Mountains. The Western part of the planar surface of the fl oodplain (179–181 m a.s.l.) is dissected by two small, artifi cial lakes, a former meander of Csigere Creek and an ephemeral channel of a karst spring. The alluvial plain is connected to the hillslope being a result of the lateral erosion of Csigere Creek with a steep slope. The Eocene bedrock and the superimposed travertine structure are clearly visible along a 195 m long section of the steep slope. The identifi cation of the Eocene limestone and the young travertine junction is quite diffi cult, because the travertine contains a lot of reworked fossils (Nummulites sp.) from Eocene layers. However, their mass is lower in the travertine structure than in the Eocene bedrock. In addi- tion, the typical overhanging slopes of travertines rimstone barriers also prove their karst water origin. Two – 1.8 m high, 1 m deep and 1 m high, 0.5 m deep – overhanging slope hollows (Photo 1) were also observed close to each other in the travertine struc- ture. All of the observations prove a former, intense period of spring activity. The Eastern part of the fl oodplain is connected to the hillslope with a gentle slope. There is no travertine, only Eocene limestone is exposed along a short, 1 m long section between the slope and the fl oodplain. The Eastern part of the fl oodplain is covered by waterlogged surface patches. They occur in an area of 200 m long and 20–30 m wide along the fl oodplain and their areas are ~1,400 m2, 180 m2 and 420 m2, respectively, extending from Southeast to Northwest. They are separated from the fl oodplain with a 20–50 cm high berm. 12 clearly visible karst water springs were identifi ed on the most extensive wa- terlogged surface patch and 8 others on the smaller patches at 180.6 m a.s.l. 255 The number of the identifi ed karst water springs is lower than their real number due to their diffi cult-to-reach location and the dense vegetation cover. The vegetation indicates the temperature of the karst water springs (10–12 °C). Vegetation covered the waterlogged surface patches during our fi eldtrips in February (Photo 2). The outfl ow waters run in small, 0.5–1.5 deep erosional channels to the Csigere Creek, however, measuring the discharge was impossible. The rejuvenation of the karst spring activity is shown by the recent yellow and reddish, calcareous mud and the lack of travertines in the surrounding of the springs (Photo 3). The calcareous mud coats leaves and boughs and it forms low rimstone barriers (Photo 4). Underwater karst spring outlets were observed in the Northern part of the reservoir, South from the dam. The frozen underwater karst springs being warmer than the water of the reservoir melted and broke through the ice on the reservoir (Photo 5). There is a quarry, 40 m southwest from the reservoir on Oligocene- Miocene gravels (Figure 5). Reed (Poaceae australis) patches and willows (Salix alba) indicates the karst water springs at the northern end of the mining claim. The spring activity is not so intense here the water leaks and fi lls up the mining claim. 0.5 m thick calcareous mud was deposited at the mouth of the spring, however, it's colour is lighter comparing to the mud mentioned above, prob- ably due to the lower concentration of iron compounds. Photo 1. Typical fossil travertine structure on the steep slope of the Csigere Creek (Photo by Kovács, I.P.) 256 Photo 2. Warm (12 °C) karst water of waterlogged surfaces around the springs with greenery in February 2013. (Photo by Kopecskó, Zs.) Photo 3. Leaves covered by recent calcareous mud near the springs (Photo by Kovács, I.P.) 257 Photo 4. Approx. 3 cm high recent rimmstone dams near karst springs (Photo by Kovács, I.P.) Photo 5. Underwater karst springs brake trough the ice of the water reservoir in February 2013. (Photo by Kovács, I.P.) 258 The results of the chemical analysis of water The content included in the analysis of water samples mineral follows a com- mon patt ern (Table 1 and 2). The HCO- from 345.5 to 394 mg/l Ca2+ were meas- ured from 99.5 to 146.7, and Mg2+ is between mg/l 33.6 and 41.4. The Ca2+ and Mg2+ ratio is between 2.7–2.8. The hardness of the samples varied from 15.9 to 18.1, while permanent hardness is somewhere between 22 and 29.9. Three springs of the Széki Reservoir in the Northwest part provided very similar data, while some parameters (of the springs) showed signifi - cant diff erences in the southwest part of Széki Reservoir. The resulting Ca2+ in water compared to 30–40 Mg2+ con- tent of 3–4 mg/l is greater than that of the average of other sources. It aff ects all of the permanent hardness of which more than 7 units of other sources of water. The measured results collected and published by Szádeczky-Kardoss, E. (1940, 1941) represent highland karst water mineral content and temperature (Table 2). GIS results According to the results of the comparison of the "original" karst water level (Csepre- gi, A. 2007) and the height values of the mapped karst water springs (Figure 6), it is proved that the recent spring activity is under the "original" karst water level. Karst springs being Northwest from the reservoir are 4.2–5.6 m below the “original” level on average, but the karst spring west from the reservoir is just 0.5–1.5 m below it. At the red mud reservoir No. 10, the values are between 7 and 6 m, furthermore, the older sludge reservoirs are 4–6 m deeper than the "original" karst water level. Using the "original" karst water level by Jaskó, S. (1959), the results are quite diff erent (Figure 7). The Northwestern karst springs are situated 3.5–5.6 m higher than the "original" karst water level, whereas the South-Western springs, reservoir No. 10 and the older sludge reservoirs are located 15–16 m, 15–20 m and 20–35 m higher, respectively, than the “original” karst water level. Discussion and conclusion The comparison of the mineral content and the temperature of the water sam- ples from the examined springs and the comparison of the obtained results Table 1. Measured chemical parameters of water samples Parameter Amount Temperature Ca2+ Mg2+ Ca2+ : Mg2+ HCO- Temporary hardness Permanent hardness 10–14°C 70–110 mg/l 30–50 mg/l 2.1–2.7 dominance 15–23 20–25 259 Ta bl e 2 . C he m ic al a nd p hy sic al p ar am et er s o f w at er sa m pl es o f k ar st sp rin gs a nd th eir co m pa ris on w ith th e s ta nd ar d ka rs t w at er p ar am et er s ( Sz ád ec zk y– Ka rd os s, E. 1 94 0, 1 94 1) St an da rd so lu tio n H C l ED TA In di ca to r Ph en ol ph – th al ei n M et hy l o ra ng e M ur ex id Er io ch ro m eb la ck T V (m L) c (N ) f E( g/ ge kv ) 10 0. 00 0. 10 1. 00 24 61 .0 1 6. 12 – – – – – 10 0. 00 0. 1 1. 00 43 61 .0 6. 13 – – – – – – – – – – 10 0. 00 0. 05 1. 06 38 40 .0 8 2. 13 – – – – – 10 0. 00 0. 05 1. 06 38 24 .3 2 1. 29 – – – – – – – – – – H C O 3 Ph en ol ph – th al ei n al ka lin ity To ta l al ka lin ity Te m po ra ry ha rd ne ss C a2+ M g2+ To ta l ha rd ne ss D at e 11 .0 1. 20 13 11 .0 1. 20 13 V (m L) c (m g/ L) dG H o V (m L) c (m g/ L) V (m L) c (m g/ L) dG H o I. 6. 45 6. 35 6. 35 5. 65 39 4. 5 38 8. 3 38 8. 3 34 5. 5 0. 0 0. 0 0. 0 0. 0 6. 5 6. 5 6. 4 5. 7 18 .1 17 .8 17 .8 15 .9 4. 90 4. 85 4. 85 6. 40 10 4. 5 10 3. 4 10 3. 4 13 6. 4 2. 60 2. 60 2. 95 3. 20 33 .6 33 .6 38 .2 41 .4 22 .3 22 .3 23 .2 28 .6 II . II I. IV . 260 Ta bl e 2 . (C on tin ue d) D at e 18 .0 1. 20 13 18 .0 1. 20 13 I. 6. 20 6. 35 6. 30 6. 28 6. 15 6. 15 6. 15 6. 15 6. 45 6. 40 6. 40 6. 42 6. 25 6. 20 6. 30 6. 28 37 92 38 8. 3 38 5. 3 38 4. 3 37 6. 1 37 6. 1 37 6. 1 37 6. 1 39 4. 5 39 1. 4 39 1. 4 39 2. 4 38 8. 3 37 9. 2 38 5. 3 38 4. 3 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 0. 0 6. 2 6. 4 6. 3 6. 3 6. 2 6. 2 6. 2 6. 2 6. 5 6. 4 6. 4 6. 4 6. 4 6. 2 6. 3 6. 3 17 .4 17 .8 17 .7 17 .6 17 .3 17 .3 17 .3 17 .3 18 .1 18 .0 18 .0 18 .0 17 .8 17 .4 17 .7 17 .6 4. 65 4. 80 4. 70 4. 72 4. 75 4. 75 4. 75 4. 75 4. 80 4. 80 4. 75 4. 78 6. 85 6. 90 6. 90 6. 88 99 .1 10 2. 3 10 0. 2 10 0. 6 10 1. 3 10 1. 3 10 1. 3 10 1. 3 10 2. 3 10 2. 3 10 1. 3 10 2. 0 14 6. 0 14 7. 1 14 7. 1 14 6. 7 2. 80 2. 75 2. 90 2. 82 3. 30 2. 80 2. 95 3. 02 2. 85 2. 85 2. 90 2. 87 3. 20 3. 15 3. 15 3. 17 36 .2 35 .6 37 .5 36 .4 2 42 .7 36 .2 38 .2 39 .0 36 .9 36 .9 37 .5 37 .1 41 .4 40 .7 40 .7 41 .0 22 .2 22 .5 22 .6 22 .4 24 .0 22 .5 22 .9 23 .1 22 .8 22 .8 22 .8 22 .8 29 .9 29 .9 29 .9 29 .9 II . II I. IV . D at e 15 .0 2. 20 13 15 .0 2. 20 13 I. 5. 80 5. 80 5. 85 5. 82 35 5. 4 35 5. 4 35 8. 4 35 6. 4 0. 0 0. 0 0. 0 0. 0 5. 8 5. 8 5. 9 5. 8 16 .3 16 .3 16 .5 16 .4 4. 70 4. 65 4. 65 4. 67 10 0. 2 99 .1 99 .1 99 .5 2. 95 3. 00 3. 00 2. 98 38 .2 38 .8 38 .8 38 .6 22 .8 22 .8 22 .8 22 .8 II . 5. 90 5. 95 5. 95 5. 93 36 1. 5 36 4. 6 36 4. 6 36 3. 5 0. 0 0. 0 0. 0 0. 0 5. 9 6. 0 6. 0 5. 9 16 .6 16 .7 16 .7 16 .7 4. 60 4. 75 4. 75 4. 70 98 .1 2 10 1. 3 10 1. 3 10 0. 2 2. 75 2. 70 2. 60 2. 68 35 .6 34 .9 33 .6 34 .7 21 .9 22 .2 21 .9 22 .0 II I. 6. 00 5. 95 5. 95 5. 97 36 7. 6 36 4. 6 36 4. 6 36 5. 6 0. 0 0. 0 0. 0 0. 0 6. 0 6. 0 6. 0 6. 0 16 .9 16 .7 16 .7 16 .8 4. 85 4. 70 4. 65 4. 73 10 3. 4 10 0. 2 99 .1 10 0. 9 2. 80 2. 80 2. 85 2. 82 36 .2 36 .2 36 .9 36 .4 22 .8 22 .3 22 .3 22 .5 261 Fig 6. The height of the original karst water level (Jaskó, S. 1959) compar- ing to the DEM of the surface (area ‘C’ inside Fig. 3). – 1 = water course; 2 = water reser- voir; 3 = sludge reservoir ; 4 = residential area; 5 = primary road; 6 = secondary road; 7 = rail road; 8 = karst spring (Coloured chart: the height values of the original karst water level comparing to the DEM.) Fig 7. The height of the original karst water level (Csepreg i , A . 2007) comparing to the DEM of the surface (area ‘C’ inside Fig. 3). – 1–8: For explana- tion see Fig. 6. 262 with earlier data undoubtedly prove the deep, karstic origins of the springs. It is even more obvious if we compare the obtained data to the low mineral content of the shallow springs in the Tatra Mountains (Żelazny, M. et al. 2012). The mineral properties of spring Nr. IV also underline that some of its prop- erties being diff erent from those of other springs can be explained by the diff erent bedrocks. The water chemistry results match the observations made during geo- morphologic mapping and fi eld measurements. Earlier spring activity is proven by the spring limestone visible on the sides of the valley of Csigere Creek. When the bed of the stream deepened, spring activity might have relocated to lower areas. The lowering of karst water level due to mining must have played a signifi cant role in the drying up of the springs, however, it is impossible to determine the location of the old springs. The geomorphological situation of the recent springs and the sinter barriers all suggest that spring activity in the examined area is only a few years old. We must note, however, that Northwest from the Széki Reservoir, the leaking of water is extensive but sampling and measuring are not possible due to the conditions of the area at the moment. To provide some data on the topic of refi lling karst water system, we used a map comparing the prior karst water level and DDM. The 10 m or larger height diff erence between Jaskó (1959) and Csepregi (2007) type karst water isohypses posed a problem. Scientifi c knowledge about the hydro-geological conditions of the karst water system between the creation of the two models has greatly in- creased in the almost 50 years, so the later map is probably more accurate than the previous one. It is proven by the position of the springs of the Széki Reservoir. As all the springs originate multiple meters below the calculated origi- nal karst water level, we can claim that the karst water system has been refi lled up to the height of the springs (180–190 m a.s.l.) or even higher. We can only extrapolate that value to the entire karst water reservoir only with restrictions, there is a poor availability of research data concerning the area. Outlook The refi ll of the karst water system and the rejuvenation of the dried up karst springs will have an increasingly intense eff ect on the rest of the mountain range, so their investigation is a national economic interest. Another reason is that the rise of the water level can have some unexpected negative or even catastrophic consequences besides the positive ones. The potential negative ef- fects will take place rather along the lines of the increased number of sinkholes and the valleys of sudden fl oods caused by the rise of the karst water levels (Waele, J.D. et. al. 2011) and not in the human-made surroundings causing damages in the built environment. 263 One of the already aff ected areas is the town of Tata where the return of 30–40 karst springs, which was signifi cant before the drop in water level, is endangering the residential buildings of an area populated during the decrease of water level (Ballabás, G. 2004). The volume of the springs and the rejuvenation of springs in higher locations (Tóth, M. 2002; Horváthy, L. and Lénárt, L. 2009) further in- crease the size of fl ooded areas and the number of damaged buildings. The general rise of karst water level will aff ect many towns in the mountains, therefore the re-examination of buildings and the review of fl ood preven- tion measures created during the time of lower water levels is more and more important. The study was not aimed to reveal the reasons of the catastrophic events at the Ajka mud-reservoir, however, the partial refi ll of the karst water reservoir and the rejuvenation of karst springs can explain the high levels of underground water and the increased water supply in the reservoir and in its surroundings (Mecsi, J. 2012; Turi, D. et al. 2013). Since the compartments storing the mud are in the valley of the Torna Stream, below the „original” karst water level, more springs can be expected to appear. Due to the fact that there are no eff ective defences, the surface water removal system created by Schweitzer, F. (2010) should be used again. It could help relieve the burden caused by the leaking surface water in the area. A positive eff ect of the rise in karst water levels is the stabilization of the spring volume of Hévíz lake, the refi ll of the cave lake in Tapolca, the rejuvenation of the Fényes springs in Tata and many others, and the increase in the volume for the hot water springs of Buda. All these provide economic benefi ts through tourism. The water level of Lake Balaton has dropped considerably, approxi- mately by 70 cm, due to the dry years between 2000 and 2003 (Somlyódy, L. 2005). Our research was conducted in the Transdanubian Mountains to apply the results of the investigation of karst water in case of Lake Balaton, namely, in respect of the raise of water level. However, that idea was rejected mainly because of the natural refi ll of the lake and also because of the small amount of available karst water and the potential negative side eff ects of the process (Somlyódy, L. and Honti, M. 2005; Tombácz, E. et al. 2005). The studies have discovered, though that karst water does not in- fl uence the water quality of the lake negatively (Simonffy, Z. 2005). During the lowering of karst water level related to mining, streams carried water to the lake draining the water in mines. The travertine in Balatonfüred, the hot springs at the ship factory in Balatonfűzfő and the aforementioned streams prove that Lake Balaton was the base level of erosion for karst springs. The volume of the springs will rise with the karst water level which will infl uence the water level and the quality of Lake Balaton positively. 264 REFERENCES Alföldi, L. 2007. A Dunántúli-középhegység földtani körülményei (Geological properties of the Transdanubian Mountains). In Bányászati karsztvízszint-süllyesztés a Dunántúli- középhegységben. Eds. Alföldi, L. and Kapolyi, L. Budapest, MTA FKI, 49–75. Ballabás, G. 2004. Visszatérő karsztforrásokkal kapcsolatos településfejlesztési és környezetvédelmi lehetőségek és veszélyek Tata város példáján (The possibilities of urban development and environmental protection at Tata, due to the rejuvenation of karst springs). Geográfus Doktoranduszok VIII. Országos Konferenciája. Szeged, SZTE TTK Természeti és Geoinformatikai Tanszék. CD ROM, 11 p. Bohn, P. ed. 1983. Magyarország mélyfúrási alapadatai. II. Közép-Dunántúl, 1851–1973. (Borehole data of Hungary II. Middle part ofTransdanubia, 1851–1973). Budapest, Magyar Állami Földtani Intézet, 223–224. Csepregi, A. 2007. A karsztvíztermelés hatása a Dunántúli-középhegység vízháztartására (The eff ect of karst water sunking on the karst water reservoir of the Transdanubian Mountains). In Bányászati karsztvízszint-süllyesztés a Dunántúli-középhegységben. Eds. Alföldi, L. and Kapolyi, L. Budapest, MTA FKI, 77–112. Csepregi, A., Izápy, G. and Klecskó, B. 2004. A tatai források és vízműkutak vizsgálata (The investigation of karst springs and waterworks at Tata). Hidrológiai Tájékoztató 1. 52–58. Cvijič, J. 1893. Das Karstphänomen. Versuch einer morphologischen Monographie. Wien, Geographische Abhandlungen, 113 p. Dövényi, Z. ed. 2010. Magyarország kistájainak katasztere (The cadastre of the Hungarian microregions). Budapest, MTA FKI, 578–579. Grund, A. 1903. Die Karsthydrographie. Studien aus Westbosnien. Leipzig, Geographische Abhandlungen, B.G. Teubner, 201 p. Höfer, H. 1912. Grundwasser und Quellen. Eine Hydrogeologie des Untergrundes. Braunschweig, F. Vieweg and Sohn, 135 p. Horváthy, L. and Lénárt, L. 2009. Tata, Fényes-fürdő, fakadó ásványvizek okozta havaria- helyzet – a megoldása annak gazdasági értékei mentén (The emergency, caused by the rejuvenation of karst springs and its solution regarding to the economical goods at Tata). Miskolci Egyetem Közleményei, Serie A, Bányászat 77. 47–64. Jaskó, S. 1959. A földtani felépítés és a karsztvíz kapcsolata a Dunántúli-középhegység- ben (The connection between the geological builtup and the karst water in the Transdanubian Mountains). Hidrológiai Közlöny 4. 289–297. Kállai G. 1927. A triászvíz és a magyar energiakérdés (Triassic water and the energy in Hungary). Bányászati és Kohászati Lapok 60. (5): 87–93. Katzer, F. 1909. Karst und Karsthydrographie. Sarajevo, 94 p. Keilhack, K. 1912. Lehrbuch der Grundwasser und Quellenkunde. Berlin, 545 p. Lehmann, O. 1932. Die Hydrographie des Karstes. Lepzig und Wien, 212 p. Mecsi, J. 2012. Some technical aspects of the embankment failure at the Ajka red mud reservoir. Continous Surface Mining, Latest Developments in Mine Planning 25–27th June, 2012, 21–33. Mitasova, H., Mitas, L. and Harmon, R.S. 2005. Simultaneous spline approximation and topographic analysis for lidar elevation data in open source GIS. IEEE GRSL 2. (4): 375–379. Schréter, Z. 1940. A karsztvízről (The karst water). Hidrológiai Közlöny 20. (1): 114–119. 265 Schweitzer, F. 2010. Channel regulation of Torna Stream to improve environmental condi- tions in the vicinity of red sludge reservoirs at Ajka, Hungary. Hungarian Geographical Bulletin 59. (4): 347–359. Schweitzer, F. and Viczián, I. 2011. Magyarországi vörösiszap-tározók mint potenciális környezeti veszélyforrások (Red sludge reservoirs in Hungary, as potential envi- ronmental risk). In Katasztrófák tanulságai. Ed. Schweitzer, F. Budapest, MTA FKI, 69–100. Simonffy Z. 2005. A vízpótlás lehetősége karsztvízből (The possibility of water supply from karst water). Vízügyi Közlemények 87. (1): Supplement, 235–248. Somlyódy, L. 2005 A balatoni vízpótlás szükségessége: tenni vagy nem tenni? (The neces- sity of water supply of Lake Balaton: to do or not to do?). Vízügyi Közlemények 87. (1): Supplement, 9–62. Somlyódy, L. and Honti, M. 2005. A Balaton vízpótlása: lehetünk-e elővigyázatosak? (The water supply of Lake Balaton: we can be careful?) Magyar Tudomány 166. (5): 570–579. Szádeczky-Kardoss, E. 1940. A Dunántúl karsztvizei (Karst waters of Transdanubia). Hidrológiai Közlöny 20. (7–12): 120–135. Szádeczky-Kardoss, E. 1941. A Dunántúli-középhegység karsztvizének néhány prob- lémájáról (Some aspects on the karst water in the Transdanubian Mountains). Hidrológiai Közlöny 21. (7–12): 67–92. Szádeczky-Kardoss, E. 1948. A Dunántúli-középhegység karsztvíz térképe (The karst water level map of the Transdanubian Mountains). Hidrológiai Közlöny 28. (1–4): 2–3, 58–60. Tombácz, E., Gulyás, P. and Mozsgai, K. 2005. A balatoni vízpótlás lehetséges megoldásainak környezeti vizsgálata (The environmental investigation of the solution of water sup- ply of Lake Balaton). Vízügyi Közlemények 87. (1): Supplement, 283–312. Tóth, M. 2002. A tatai források visszatérésének prognózisa (The forecast of the rejuvenation of karst springs at Tata). Vízügyi Közlemények 84. (2): 194–213. Turi, D., Pusztai, J. and Nyári, I. 2013. Causes and circumstances of red mud reservoir dam failure in 2010 at MAL Zrt. factory site in Ajka, Hungary. 7th International Conference on Case Histories in Geotechnical Engineering. (in press) Vadász, E. 1940. A Dunántúl karsztvizei (Karst waters of Transdanubia). Hidrológiai Közlöny 20. (1): 120–135. Waele, J.D., Gutiérrez, F., Parise, M. and Plan, L. 2011. Geomorphology and natural haz- ards in karst areas. A review 134. 1–8. Żelazny, M., Wolanin, A. and Płaczkowska, E. 2013. Hypsometric factors for diff erences in chemical composition of Tatra National Park spring waters. Polish Journal of Environmental Studies 22. (1). 289–299. Standard Methods for the Examination of Water and Wastewater. 15th Edition, 1980. Hungarian standards (MSz) International standards (ISO) 266 AVAILABLE! Ethnic map of Hungary 1941 + Ethnic map of present territory of Hungary 2001 Scale 1:500 000 Authors: KOCSIS, K. and BOTTLIK, ZS. Geographical Research Institute, Hungarian Academy of Sciences, Budapest, 2009 The latest (eighth) piece of ethnic map series of the Carpathian Basin was an att empt to draft the changes that have taken place in the ethnic structure during the past fi ve hun- dred years as well as to display its present state with the help of ethnic maps and a chart - in our case referring to the present-day territory of Hungary. On the front pages of our work consist- ing of two sheets ethnic maps of the present-day territory of Hungary are displayed with the help of pie-charts, based on ethnic ( 2 0 0 1 ) a nd mother tongue (1941) data. Population-proportional p i e -char t s provide information on the territorial distribu- tion of the major ethnic groups and on the contemporary admin- istrative division. T h e nine supplementary maps on the re- verse show the lingual-ethnic com- position of the present-day ter- ritory of Hungary in 1495, 1715, 1784, 1880, 1910, 1930, 1941, 1990 and 2001 respectively. The chart here explores the quantitative and proportional changes of the main ethnic groups’ population between 1495 and 2001. The series of maps displays absolute or relative ethnic majorities only in the inhabited areas of the sett lements which had been mentioned in the source referred. Uninhabited areas with no permanent sett lements are shown as blank spots. Price: EUR 10.00 – For sale only in pairs! O rde r : Geog rap h i c a l Ins t i tu t e R C A E S H A S Library. H-1112 Budapest, Budaörsi út 45. E-mail: magyar.arpad@csfk .mta.hu << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.3 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /DetectCurves 0.0000 /ColorConversionStrategy /LeaveColorUnchanged /DoThumbnails false /EmbedAllFonts true /EmbedOpenType false /ParseICCProfilesInComments true /EmbedJobOptions true /DSCReportingLevel 0 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize false /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveDICMYKValues true /PreserveEPSInfo true /PreserveFlatness true /PreserveHalftoneInfo false /PreserveOPIComments true /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /CropColorImages true /ColorImageMinResolution 300 /ColorImageMinResolutionPolicy /OK /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageMinDownsampleDepth 1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile (None) /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False /CreateJDFFile false /Description << /ARA /BGR /CHS /CHT /CZE /DAN /DEU /ESP /ETI /FRA /GRE /HEB /HRV (Za stvaranje Adobe PDF dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. 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