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Study of water flow and geochemical processes in the unsaturated zone of carbonate and salt karst
Kamas, Jiří ; Bruthans, Jiří (advisor) ; Tesař, Miroslav (referee) ; Buzek, František (referee)
Water flow and geochemical processes within the unsaturated zone (UZ) in two distinct types of karst environment were investigated using natural tracers (chemistry, stable isotopes 13 C, 18 O, 2 H, and 3 H, 14 C, 87 Sr/86 Sr). The extent of horizontal flow component and the response of drip water chemistry to recharge events were examined in the Moravian Karst (Czech Republic), while the character of water flow and its chemistry were studied in salt diapirs in southeastern part of the Zagros mountains (Iran). Under the conditions of well-developed epikarst, the horizontal flow component, defined as Hmax/T (Hmax = horizontal migration component, T - thickness of VZ) typically reaches values of 0.1 - 0.6 (Moravian and Slovenian Karst). However, in areas where epikarst was stripped off by glacial or human activity, the proportion of horizontal flow component is far greater (Hmax/T 1.6 - 24). This parameter is vital for the design of water source protection zones above caves. Nitrate mean residence time in 120 m thick VZ of the Moravian karst exceeded 16 years. The VZ above the Ochoz Cave (Moravian Karst) represents a semi-open to open system with respect to soil CO2. Under a high drip rate (high flow), the event water only made 5% of the total. During the year, water degassing and so called prior...
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Study of water flow and geochemical processes in the unsaturated zone of carbonate and salt karst
Kamas, Jiří ; Bruthans, Jiří (advisor) ; Tesař, Miroslav (referee) ; Buzek, František (referee)
Water flow and geochemical processes within the unsaturated zone (UZ) in two distinct types of karst environment were investigated using natural tracers (chemistry, stable isotopes 13 C, 18 O, 2 H, and 3 H, 14 C, 87 Sr/86 Sr). The extent of horizontal flow component and the response of drip water chemistry to recharge events were examined in the Moravian Karst (Czech Republic), while the character of water flow and its chemistry were studied in salt diapirs in southeastern part of the Zagros mountains (Iran). Under the conditions of well-developed epikarst, the horizontal flow component, defined as Hmax/T (Hmax = horizontal migration component, T - thickness of VZ) typically reaches values of 0.1 - 0.6 (Moravian and Slovenian Karst). However, in areas where epikarst was stripped off by glacial or human activity, the proportion of horizontal flow component is far greater (Hmax/T 1.6 - 24). This parameter is vital for the design of water source protection zones above caves. Nitrate mean residence time in 120 m thick VZ of the Moravian karst exceeded 16 years. The VZ above the Ochoz Cave (Moravian Karst) represents a semi-open to open system with respect to soil CO2. Under a high drip rate (high flow), the event water only made 5% of the total. During the year, water degassing and so called prior...
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Study of vadose zone in northern part of Moravian Karst
Gregorová, Anita ; Bruthans, Jiří (advisor) ; Kamas, Jiří (referee)
This study is focused on the flow through the uppermost part of the unsaturated zone in karstified areas. The information about distribution of transit times and chemical reactions taking place in the unsaturated zone is based on isotopic and chemical composition of cave dripwaters, precipitations and water caught by gravitation lysimeters. The water balance was calculated using measurements of intensity of dripwaters and amounts of water caught by lysimeters and rain gauges. The velocity of a hydraulic shockwave between monitored objects was also estimated according to the delay between significant precipitation event and dripwater intensity increase. The field study took place in the Němcova 1 cave in the northern part of Moravian Karst, near the village Suchdol. It was carried out during the hydrological year 2010/2011. The cave is about 13 m under the surface. The information about composition of overlaying rock above the cave was obtained using geoelectrical and electromagnetic measurements. Studied geological environment is built of 0.5 - 1.5 m of soil, 0.5 - 3.5 m of epikarst and a layer of massive limestone as thick as 10 m. About 70 to 90 % of dripwaters have residence time over 4 years. The distribution of transit time of younger water can be described using the exponencial model (well...
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Environmental tracers (18O, 3H, CFCs, SF6) exploitation for study of mean residence time and flow pattern of dripping water and karst springs (Moravian Karst)
Bruthans, J. ; Zeman, Ondřej ; Jež, M. ; Himmel, J. ; Buzek, F. ; Melková, J. ; Oster, H. ; Geršl, M.
Mean residence time and flow pattern was studied in unsaturated zone of Ochoz Cave in southern part of Moravian Karst by means of 18O in the years 2001 to 2003. The results of study showed relatively long residence time in the unsaturated zone (about 50% komponent with residence time exceeding one year). The proportion components coming from different reservoirs were computed from two components (soil/epikarst; meltwater). The results clearly indicate, that more than 50% of water (nearly 100% in 2003) in dripping waters was derived from soil/epikarst water, which originate from (late) summer precipitations (heavy 18O content)! It means that infiltrating snowmelt water was expelling (by piston flow effect) the summer water from soil and/or epikarst. Water from snowmelt was then lost by evapotranspiration in summer time. If this effect is common in Langer period, it can change composition of d18O in dripping waters and hence also in dripstones precipitating from these waters.
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