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Hydrology of Amateur cave and sinking streams focused on tracer tests
Gregorová, Anita ; Bruthans, Jiří (advisor) ; Vojtěchová, Anna (referee)
This study briefly summarizes methodology of tracer studies in karst areas (the way how they were carried out and their evaluation). Second part of the study specifies geological, hydrogeological and hydrological situation of the area of interest - northern part of the Moravian Karst, surroundings of Sloup - using available literature on that topic. Description of the area was completed with field measurements done by the author. Their results can be used as a basis for possible future surveys.
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Channels eroded by groundwater flow in Strelec quarry: erosion processes and factors influencing channel evolution
Soukup, Jan ; Bruthans, Jiří (advisor) ; Grmela, Arnošt (referee)
Large depression cone in water table was formed due to mining in surroundings of Střeleč quarry. The concentrated inflow from conduits to quarry is up to 70 l/s. Large conduit systems are created by flowing water into the quarry. The biggest conduit system was at least 300 m long and 17 m high with maximum calculated volume of 22 thousands m3 . Evolution of these conduits usually takes several months to few years. Fast conduit evolution allows to study erosion processes in detail in situ. In the thesis I am describing conduits, character of flow and erosion processes. Measured flow velocities in conduits are up to 0,4 m/s with hydraulic gradient 1 to 5%. Flow velocities and hydraulic gradients are typical for piping erosion. Piping initially forms small protoconduits. The bigger conduits are formed as water is progressively drained from larger area. Conduits are following fracture surfaces, which are also limiting the conduit propagation to the sides. Above water table the conduits are enlarged mainly by mass wasting of undercut sandstone slabs. For distinguishing less and more erodible parts of sandstone, we adapted and partially developed a method for measuring erodability (REI) and drilling resistance (DR). Both are used to compare different types of sandstone surfaces. In lowermost part of the...
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Channels eroded by groundwater flow in Strelec quarry: erosion processes and factors influencing channel evolution
Soukup, Jan ; Bruthans, Jiří (advisor) ; Grmela, Arnošt (referee)
Large depression cone in water table was formed due to mining in surroundings of Střeleč quarry. The concentrated inflow from conduits to quarry is up to 70 l/s. Large conduit systems are created by flowing water into the quarry. The biggest conduit system was at least 300 m long and 17 m high with maximum calculated volume of 22 thousands m3 . Evolution of these conduits usually takes several months to few years. Fast conduit evolution allows to study erosion processes in detail in situ. In the thesis I am describing conduits, character of flow and erosion processes. Measured flow velocities in conduits are up to 0,4 m/s with hydraulic gradient 1 to 5%. Flow velocities and hydraulic gradients are typical for piping erosion. Piping initially forms small protoconduits. The bigger conduits are formed as water is progressively drained from larger area. Conduits are following fracture surfaces, which are also limiting the conduit propagation to the sides. Above water table the conduits are enlarged mainly by mass wasting of undercut sandstone slabs. For distinguishing less and more erodible parts of sandstone, we adapted and partially developed a method for measuring erodability (REI) and drilling resistance (DR). Both are used to compare different types of sandstone surfaces. In lowermost part of the...
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Flow pattern and hydraulic response propagation in selected caves of Moravian Karst
Kůrková, Iva ; Bruthans, Jiří (advisor) ; Knížek, Martin (referee)
This thesis is divided into two parts. The first one is focused on tracer tests carried out in several karst conduits in the Moravian Karst. Several conduits were tracer repeatedly during different discharges. Flow velocity, flow cross section area, longitudinal dispersivity and Peclet number were plotted against discharge for each studied conduit. Based on this comparison of parameters I deduced characteristics of karst conduits for example presence of phreatic channel or vadose channel or multiple channels. I also focused on comparison of my results with publications dealing with the same subject elsewhere in the world. Second part of the thesis is based on measurements of water stage, dischargeand temperature by pressure transducers at inlet and outlet points of karst conduit logged in 10 minutes interval. The goal was to find a relation between the velocity of hydraulic response propagation and discharge. Unfortunately, results show no correlation because there are probably more parameters influencing the velocity such as ratio of vadose/phreatic segments which may change rapidly during flood events.
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Hydrology of Amateur cave and sinking streams focused on tracer tests
Gregorová, Anita ; Bruthans, Jiří (advisor) ; Vojtěchová, Anna (referee)
This study briefly summarizes methodology of tracer studies in karst areas (the way how they were carried out and their evaluation). Second part of the study specifies geological, hydrogeological and hydrological situation of the area of interest - northern part of the Moravian Karst, surroundings of Sloup - using available literature on that topic. Description of the area was completed with field measurements done by the author. Their results can be used as a basis for possible future surveys.
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