Verification of the hydrotechnical parameters of the existing damming objects of rapids and torrents using modern methods and software
The dissertation is focused on verifying the applicability of modern methods and software in the field of damming torrents, as streams with a greater longitudinal slope and a significant flood regime. There are mainly two ways of use, where the first way is the use of Laser scanning technology (LIDAR) and the subsequent creation of digital models. It is primarily a channel model, as a digital terrain model (DTM), or a digital model of an existing transverse object (steps or check dams). Based on these results, further processing is then possible, for example when designing new objects or creating project documentation. The second way is the use of modern methods of hydrotechnical assessment of the watercourse bed and transverse objects of the watercourse bed. In the case of this work, the software HEC-RAS and Hydraflow express, which is a complement to the Autodesk Civil 3D program, are considered. These are methods used as a standard in the hydrotechnical assessment of watercourses with a smaller longitudinal slope, greater flow and for objects on them. The results of these methods are compared with the reference methodology according to the valid legislation and technical standards in force in the Czech Republic at the time of processing this work. Last but not least, the output is the evaluation of 50 transverse object in the Czech Republic in terms of whether they meet the requirements of applicable legislation and technical standards.
Solving the hydric regime of forest ecosystems is currently a very topical topic. Water retention in the landscape is very important and can significantly contribute to mitigating the adverse effects of climate change. For over a hundred years, the branch of damming torrents and torrents, then the damming service of torrents and torrents, has been significantly involved in this issue. (Act №117.1884 s.z.) The flow regime in torrents and mountain streams is very specific, mainly a significant runoff regime. (Ashida 1981) Larger pieces of wood and stone are also frequently transported. (Bilby, 1981; Hungr 2005) This occurs primarily due to the high longitudinal slope and resulting high flow velocity. (Hassan 2005) The mode of transport of runoff depends on the flow regime, which usually has a seasonal character in torrential streams. (Theule 2012; Bennett 2013) Due to the different regime of water flow and runoff regime, it is not always automatically possible to use procedures and measures identical to larger flows, with flows with a lower longitudinal slope and permanent flow. (Lenzi 2001) The damming of rapids requires the design of various measures for protection. Their form is primarily determined by the subject of protection and the required level of protection. (Lenzi 2001) Any measure in a complex ecosystem such as streams and mountain streams will necessarily affect the balance of the biotic components of this ecosystem. At the same time, however, the need for these measures to protect infrastructure and homes, which can be damaged by regular and completely natural floods in mountainous areas, cannot be denied. (Kettl 1994) It is always necessary to assess the intervention in the context of the whole basin, not locally. (Vokurka 2020) The current trend for the regulation of torrents and mountain streams is to ensure the best possible fusion of measures with the ecosystem. This involves the combined use of landscape engineering and stream morphological “reconstruction” methods. The proposed measures should be maximally compatible with the natural tendency of the stream to reach a stable state in the long term. All measures must be carried out in accordance with the principles of damming torrents and rapids after a proper assessment of all documents for the given area, including the impact on the environment. (Kondolf, 1996; Vokurka 2020). It is appropriate to strive for the primary use of non-invasive, preventive and close to nature measures, such as the care of vegetation and land in the watershed. (Zuna 2008) When designing new buildings, it is necessary to proceed from valid legislation and standards, i.e. (ČSN 75 2106–1 and 2), and (Declaration №239/2017 Coll.). The design of new buildings and the assessment of existing buildings is a demanding process. Any possibility of increasing efficiency and reducing time consumption using currently available modern methods is very important. The methods used at the same time are usually lengthy and consist of a large amount of calculations and manual work during measurement. New technologies such as laser scanning (LiDAR) are currently being used or tested in forestry in a relatively wide range of activities. The models created in this way are used, for example, for the assortment of raw wood cutouts. (Goodbody 2017; Alvites 2021) It is also an important part of the DPZ, which is widely used in the mass inventory of large territorial units (Adolt 2013). Also, software solutions for calculating and modeling the properties of flowing water in the streambed, the properties of objects on watercourses, floodplains and other hydrological and hydraulic attributes are widely used and widely available. (Schal 2012; Deslagen 2021; Tamiru 2021)
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