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Flow and mean residence time in karst unsaturated zone (Ochoz Cave, Moravian Karst)
Vysoká, Helena ; Bruthans, Jiří (advisor) ; Buzek, František (referee) ; Tesař, Miroslav (referee)
Flow and mean residence time in epikarst and unsaturated zone was studied above the Ochoz cave in the Moravian Karst. I studied various flow components with different residence time in unsaturated zone and the influence of soil and epikarst on seepage composition and residence time by means of several methods (longterm monitoring of conductivity, flowrate of seepage and soil water, use of environmental tracers - 18 O, 3 H, CFC and SF6, flow into the soil and detailed sampling during intesive rain events). Seepage sites Kašna in the Rudické propadání cave system and Mapa Republiky in Býčí skála were reference localities in unsaturated zone. For comparison I modeled residence time in saturated zone: at Kaprálka outlet close to the Ochoz cave, at Stará řeka (Rudické propadání) and Konstantní přítok (Amatérská cave). Mean residence time in unsaturated zone above the Ochoz cave reaches 7 - 20 years, while it is only few months in the soil (1 - 8 months, depending on the depth). At Kašna seepage site, the reasidence time is similar to the Ochoz cave - about 18 - 20 years, at Mapa republiky seepage site, it reaches 150s year due to unusual geological settings. Mean residence time in order of 10 - 20 years corresponds to storativity values (0.6 % in average) calculated from parallel water level recession...
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Flow and mean residence time in karst unsaturated zone (Ochoz Cave, Moravian Karst)
Vysoká, Helena ; Bruthans, Jiří (advisor) ; Buzek, František (referee) ; Tesař, Miroslav (referee)
Flow and mean residence time in epikarst and unsaturated zone was studied above the Ochoz cave in the Moravian Karst. I studied various flow components with different residence time in unsaturated zone and the influence of soil and epikarst on seepage composition and residence time by means of several methods (longterm monitoring of conductivity, flowrate of seepage and soil water, use of environmental tracers - 18 O, 3 H, CFC and SF6, flow into the soil and detailed sampling during intesive rain events). Seepage sites Kašna in the Rudické propadání cave system and Mapa Republiky in Býčí skála were reference localities in unsaturated zone. For comparison I modeled residence time in saturated zone: at Kaprálka outlet close to the Ochoz cave, at Stará řeka (Rudické propadání) and Konstantní přítok (Amatérská cave). Mean residence time in unsaturated zone above the Ochoz cave reaches 7 - 20 years, while it is only few months in the soil (1 - 8 months, depending on the depth). At Kašna seepage site, the reasidence time is similar to the Ochoz cave - about 18 - 20 years, at Mapa republiky seepage site, it reaches 150s year due to unusual geological settings. Mean residence time in order of 10 - 20 years corresponds to storativity values (0.6 % in average) calculated from parallel water level recession...
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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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