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The analysis of river network evolution in Ethiopian Highland
Maca, Vít ; Vilímek, Vít (advisor) ; Kliment, Zdeněk (referee)
Ethiopian highlands is one of the most various tectonic areas in the world. It lies in close proximity to Ethiopian rift system in areas with volcanic landscape. As the main factors involved in development of river networks have been identified: volcanism, tectonics, erosion. The most important factor is the erosion, that work pays closer. Using the methods of remote sensing, GIS analysis and documenting the longitudinal and transverse river profiles were surveyed area of differentiation in the types of river networks, deep of river valleys, geological strata, etc. GIS and remote sensing analysis provided more supporting data. Crucial is the analysis of the longitudinal profiles. Five rivers was profiled: Guder, Muger, Jemma, Birr, Blue Nile. Knickpoints in profiles were identified and were divided into three types according to the majority factor involved in the formation: Active uplift entire Ethiopian highlands which activizate river erosion, active uplift smaller areas, lithological. Crucial for next outputs are knickpoints linked to active uplift entire Ethiopian Highland. Lokalization of thats, were profiles divided into subprofiles, representing phasis of erosion development of entire area. During the past 31 million years, were identified 3 phases with increasing incision rates. Furthermore,...
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The susceptibility analysis of slope movements in the Jemma River basin (Ethiopian Highland)
Maca, Vít ; Vilímek, Vít (advisor) ; Kusák, Michal (referee)
Ethiopia like other developing countries depends on domestic agricultural production, struggling with infrastructure and healthcare is also at a low level. Among these factors there is also added impact of catastrophic natural processes. Landslides in this area have caused enormous material damage and also human deaths. Effects of those losses are huge and locals are dealing with them difficuly. Therefore, prevention should be a priority concern. In theoretical part the basic facts about modeling and simulation of landslides susceptibility is presented. Those facts are complemented with specific researches from Ethiopian highlands. Furthermore, it describes the methodology that was used. It compares the real distribution of slope movements against the expected occurrence across the classes of input layers. An essential part of the model is mapping work, supported with terrain work, during which 242 landslides was mapped. Model parameters are: slope, altitude, lithology, land cover, distance from geological boundary and distance to river. Slope was determined as most significant factor. Used methodology is universally applicable and the results it generates match reality well. Key words: slope movements, natural hazards, susceptibility analysis, geomorphology, Ethiopian Highland
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The analysis of river network evolution in Ethiopian Highland
Maca, Vít ; Vilímek, Vít (advisor) ; Kliment, Zdeněk (referee)
Ethiopian highlands is one of the most various tectonic areas in the world. It lies in close proximity to Ethiopian rift system in areas with volcanic landscape. As the main factors involved in development of river networks have been identified: volcanism, tectonics, erosion. The most important factor is the erosion, that work pays closer. Using the methods of remote sensing, GIS analysis and documenting the longitudinal and transverse river profiles were surveyed area of differentiation in the types of river networks, deep of river valleys, geological strata, etc. GIS and remote sensing analysis provided more supporting data. Crucial is the analysis of the longitudinal profiles. Five rivers was profiled: Guder, Muger, Jemma, Birr, Blue Nile. Knickpoints in profiles were identified and were divided into three types according to the majority factor involved in the formation: Active uplift entire Ethiopian highlands which activizate river erosion, active uplift smaller areas, lithological. Crucial for next outputs are knickpoints linked to active uplift entire Ethiopian Highland. Lokalization of thats, were profiles divided into subprofiles, representing phasis of erosion development of entire area. During the past 31 million years, were identified 3 phases with increasing incision rates. Furthermore,...
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