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Extent and morphological effects of quaternary glaciation in the northernslope of the Jizera Mts.
Černá, Barbora ; Engel, Zbyněk (advisor) ; Balatka, Břetislav (referee) ; Tyráček, Jaroslav (referee)
UNIVERZITA KARLOVA V PRAZE PŘÍRODOVĚDECKÁ FAKULTA Katedra fyzické geografie a geoekologie Rozsah a morfologické účinky kvartérního zalednění v severním svahu Jizerských hor Extent and morphological effects of quaternary glaciation in the northern slope of the Jizera Mts. doktorská disertační práce - souhrn PhD. thesis - summary Mgr. Barbora Černá (roz. Janásková) ledovce. Stáří sedimentů ze dna Rybích louček vypovídá o tom, že ledovec podlehl deglaciaci již na sklonku pleistocénu. The PhD thesis deals with paleogeographic reconstruction of glaciation in the Jizera Mts. The research was focused on issues, which were not satisfactorily solved yet: the continental glaciation extent, effects of the glacier impact on the recent relief morphology and a possibility of mountain glaciation. During the investigation additional questions about the method of Schmidt hammer measurements arose and were treated in a separate methodological study. The aims of the research are: - to delimit the maximum altitudinal extent of the continental glaciation - to determine the influence of the quaternary glaciations on relief and identify its geomorphological and sedimentary evidence - to contribute to resolve the issue of mountain glaciation in the Jizera Mts. The present work consists of six articles that were published in...
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Morphology of the Moravice valley head, the Hrubý Jeseník Mountains
Steffanová, Petra ; Křížek, Marek (referee) ; Engel, Zbyněk (advisor)
There are several amphitheatrical valley heads in the Hrubý Jeseník mountains. Velká kotlina is situated bellow Vysoká hole mountain and has been an object of interest since 19th century. Several methods of geomorfological research were used to prove pleistocene glaciation in the area. The aim of diploma work is to extend knowledge about morphology and genesis of Velká kotlina. Study area was limited by distribution board till the first right affluent of Moravice. Morphometrics characteristic of the cirque were analyzed in GIS 9.3 enviroment. Identification of the shape and size of glacial accumulations during which was used method of longitudinal and transverse shaping showed the posibility of Quartenary glaciation. Cirque is built with less resistant rocks that caused that evidence of the glaciation is not so significant as it is in Šumava mountains or Krkonoše mountains. There are two moraines identified at the valley of river Moravice. The upper one that was created during the last recession of glacier devides cirque floor into two degrees. Frontal moraine is situated behind the lip of the cirque and shows the maximum of glacier expansion. Identification of these two morains were supported by analysis of glacier sediments and by georadar method. Even though existence of moraines suggests...
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Morphology of the Křížový potok river channel in the Eastern Krkonoše Mountains
Dvořáková, Magdalena ; Kliment, Zdeněk (referee) ; Engel, Zbyněk (advisor)
This master thesis deals with the morphology of mountain river channels - with structures, patterns and shapes resulting from fluvial processes. The findings are documented on the Křížový potok river channel in the Eastern Krkonoše mountains. There are several specifics which influence the evolution of mountain river channels. The first one is high elevation change and big slope of the river, which determinate the formation of typical structures, such as waterfalls, cascades and steps, often related with pools. Plane bed, riffle-pool and dune-ripple also represent typical structures of mountain river channels. Specific microstructures are represented by potholes. River channels in forested mountain basins are affected by logs and wood debris, which create local barriers where fine-grained material accumulates. In the Křížový potok river channel, a high diversity of the channel structures can be seen. The most common structures are step-pools and cascades. The stream is influenced by large accumulation of delluvial sediments and wood debris which create obstacles to the flow.
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Rockfalls in the Jestřebí Castle area
Kaňková, Helena ; Engel, Zbyněk (referee) ; Kalvoda, Jan (advisor)
Rockfalls in the Jestřebí Castle area Abstract Rockfalls are one of essential causes of direct as well as indirect damages in residential areas. To mitigate negative impacts on society it is necessary to assess the risk posed by rockfall and choose suitable protective measures. Achievement of these targets needs a better understanding of the whole process of rockfall including natural conditions and trigger factors. Presented case study deals with rockfalls in the Jestřebí Castle area. The castle bedrock is formed by quartzose sandstones of the Cretaceous age. Stability of the masiff deteriorates in the last 200 years. The first rockfall was registered in the year 1811. Main cause is imputed to human interventions after 1400 AD when construction of the castle began, including the sandstone quarrying in 1750 - 1850 AD. As additional adverse conditions and factors were identified the weathering along conglomerate and bioturbated horizons resulted in a horizontal dissection of the sandstone outcrop and also a vertical separation along joints caused by nearby fault zone. The latest significant rockfall in October 1st 2009 wasted over 100 m3 of rocks from the western wall of the sandstone massif. Further rockfalls due to low stability of the massif can be expected in the near future. Keywords: rockfalls, slope...
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