scholarly journals The trends in the main thalweg path of selected reaches of the Middle Vistula River, and their relationships to the geological structure of river channel zone

2018 ◽  
Vol 10 (1) ◽  
pp. 554-564 ◽  
Author(s):  
Tomasz Falkowski ◽  
Piotr Ostrowski ◽  
Marek Bogucki ◽  
Dariusz Karczmarz

Abstract Research carried out by the authors’ team in the valleys of many rivers in the Polish Lowlands has shown that the contemporary morphodynamics of channel zones is highly influenced by protrusions of erosion-resistant sub-alluvial bedrock. The article presents the results of analysis of two reaches of the Middle Vistula: near Solec nad Wisłą (km 330-340) and Gołąb (km 382-388), where such protrusions have been found. At each of them, two series of bathymetric measurements were carried out during medium and low water levels in the river channel. The measurements were made using hydrographic sets integrated with a GNSS receiver. The first series of measurements was carried out in July 2004, and the second one in September 2016. In parallel with the bathymetric surveys, low-altitude aerial photographs were taken in 2016 to document the morphology of the channel zone and the condition of the river engineering structures. A comparison of the obtained bathymetric maps shows a high correspondence between the thalweg line from 2004 and that observed twelve years later. This phenomenon proves the significance of the bedrock relief beneath the modern alluvial deposits for the water flow process in the channel. The relief causes the flow to concentrate in specific zones so strongly that it contributes to the damage of river engineering structures that put limits on the channel processes. This trend of concentrating the main thalweg is also accompanied by the diversity of depositional environments of river channel facies, identified along the studied reaches.

Author(s):  
Liudmyla Kosteniuk

This publication analyzes the features of the hydrological regime and channel processes of the Iltsya River, based on regular observations and during the expedition trip in June 2019.The schemes of basin distribution and geomorphological zoning of the studied object, curves of connection of water consumption and levels Q = f (H), graphs of the course of maximum, average and minimum water levels, and also cross sections on key sites are presented in the work. Conditions of channel formation of natural watercourses are a complex and multilateral process which is closely connected with natural features of the territory of their basin.The main factors of the natural channel process are the geological structure of the area, sediment flow and grain size. These factors are key, however, the processes of channel formation are also influenced by additional factors that are temporary or local in nature. At the same time, we should not forget about the influence of the anthropogenic factor, the results of which for the basins of small rivers can sometimes even dominate for some time over the main ones mentioned above. All these factors not only affect the channel process, but also difficult to interact with each other. The geological structure, including the lithology of rocks, as well as the relief of the territory, have a direct impact on the shape of the valley, the longitudinal profile, the composition of channel-forming sediments, and hence the stability of the channel. Water runoff is the main active factor that depends on the hydrological regime of the river and determines its water content and size. The nature of the sediments and their regime is a factor that determines the rate and direction of vertical and horizontal deformations of the channel. The object of our study - is the river Iltsya, a small left tributary of the ChornyyCheremosh, which is characterized by specific geological conditions, and therefore significantly different from other small rivers in the region, including neighboring tributaries of the main river (ChornyyCheremosh). The second feature of the studied river is that the lower part of its basin is located within the Vorokhta-Putilsky ancient terraced lowlands, while the sources are formed within the Pokutsko-Bukovynian Carpathians, which in turn determines a certain specificity in the formation of its channel. This geological and geomorphological feature of the Iltsya river basin distinguishes it among numerous similar small rivers of this region of the Ukrainian Carpathians. Summarizing all the above, we have made some conclusions, the basin of the river Iltsya is currently little studied, both in terms of hydrological regime, channel processes and geomorphological studies, although in fact it is quite interesting and not typical of project, which raises many questions that require more detailed study. The presence of a long series of observations, allows us to identify general tendencies to the gradual incision of the channel in the area of the hydropost, although with little intensity. Visual inspection showed more manifestations of horizontal transformations associated with the movement of alluvial ridges and erosion of the shores. The greatest feature of the Iltsya river basin is the polymorphic formation of its channel system, because within the Vorokhta-Putil lowlands the river Iltsya and VelykyiRosysh occupy a wide valley of the ancient pliocene river, and this nuance has the greatest influence on the nature of riverbeds within its limits.


2020 ◽  
Vol 12 (1) ◽  
pp. 290-298
Author(s):  
Anna Sosnowska

AbstractThe investigation focused on the non-migrating mid-channel bars that emerged in the river channel as a consequence of river engineering. A reach of around 280 km of Middle Vistula River (Poland) was taken into account as the study site. The most vivid examples of the river engineering works potentially influencing the river channel are the ferry crossings. Along the Middle Vistula River reach, there are 17 ferry crossings that were constructed from 1970s to 1990s. A cartographic analysis was carried out to determine the influence of the ferry crossing construction over the river channel. It was performed on the basis of aerial photographs (traditional aerial photography and UAV photography). In 3 out of 17 potential localizations, the emergence of large non-migrating mid-channel bars was observed. A study of cartographic materials (from 1950s to 2000s) allowed determination of the dynamics of those bars, including time of emergence and the changes of their size.


2013 ◽  
Vol 19 (2) ◽  
pp. 268-286 ◽  
Author(s):  
Kutalmis Gumus ◽  
Halil Erkaya ◽  
Metin Soycan

Applicability of Terrestrial Laser Scanners/Scanning (TLS) in deformation measurement in dams is an active area of study. With the advance of modern technology, accuracy of measurements is much improved by developments in design of terrestrial laser scanners. Currently, this technology is used in large and complex engineering structures such as dams. Although TLS is a high cost technology, it is particularly used in monitoring of dam deformations, due to its speed in obtaining thousands of data points, ability to visualize the scanned object and its environment with high accuracy and ability to take long-range measurements. In order to determine the effect of change in water reservoir levels on body of the dam, TLS are used to take deformation measurements in different time intervals, where the water level was at maximum, minimum and medium levels. This paper provides an overview of terrestrial laser scanning technology for deformation monitoring. The concrete arch dam in Antalya Oymapinar, Turkey was used for case study. Four different scannings were performed in this dam in order to verify the replicability of TLS results on same water levels and equivalent conditions. Digital Surface Models reflecting dam surface have been created. Results obtained from surface model differences were examined using surface matching method.


Author(s):  
С.А. Мамаев ◽  
А.Р. Юсупов ◽  
А.С. Мамаев ◽  
З.А. Юсупов

В данной статье даны особенности геологического строения района газопроявления «Цущар» в Кулинском районе на отложениях среднеюрского возраста, предлагается геолого-структурная схема возможного формирования залежи нефти и газа. Незначительные проявления газоносности, связанные обычно с минеральными источниками и подчиненные мощной толще юрских сланцев, развитых на значительных площадях нагорного Дагестана, начали обращать на себя внимание с 1931 г., в связи с поисками месторождений легких редких газов. Анализы газов показывают повышенное содержание легких редких газов в целом ряде месторождений нагорного Дагестана. Кроме группы месторождений Южного Дагестана известен пока только один выход горючего газа в Центральном Дагестане – Кулинском районе. На него указывает в своем рукописном отчете Дагестанскому Совнархозу геолог Н. М. Леднев. Этот выход подчинен юрским сланцам, связан с нарушениями неотектонического характера, образованными в результате сейсмической активизации региона. Цель исследования. Целью наших исследований является обоснование перспектив газоносности Горного Дагестана. На изучаемой территории отмечается наличие неправильных куполовидных складок с неожиданными направлениями их осей, пересекающими основное направление складчатости, частичными местными уклонениями в залегании пластов. Методы исследования. Основными методами исследования при изучении перспектив газоносности Горного Дагестана являлись геолого-структурный, стратиграфический, морфологический, тектонический и дешифрирование аэрофотоснимков. Результаты исследования. По сравнению с Предгорным Дагестаном и Прикумским районом, Горный Дагестан был подвержен более интенсивным геотектоническим движениям, неоднократно подвергался складчатости, испытал инверсию, со значительно большей амплитудой, что привело к усиленной денудации, развитию трещиноватости и разрывов, метаморфизму пород и органических образований. Все это отрицательно влияло на сохранение нефти и газа. Можно предполагать, что многие залежи, сформировавшиеся при прохождении продуцирующими толщами главной фазы нефтеобразования, были разрушены в периоды активизации тектонической деятельности на рубеже юры и мела, мела и палеогена. В дальнейшем шла генерация, преимущественно, газообразных углеводородов, которые при особенно благоприятных условиях могли сохраниться до настоящего времени. По результатам исследований можно утверждать, что газовое проявление Цущар могло проявиться в 1622, 1652 гг. в результате сильных землетрясений, эпицентр которых располагался в пределахисследуемого района This article describes the features of the geological structure of the Tsushar gas show area in the Kulinsky region on the Middle Jurassic deposits, and proposes a geological-structural diagram of the possible formation of oil and gas deposits. Minor manifestations of gas content, usually associated with mineral springs and subordinate to a thick stratum of Jurassic shales, developed over large areas of highland Dagestan, began to attract attention from 1931, in connection with the search for deposits of light rare gases. Gas analyzes show an increased content of light rare gases in a number of fields in highland Dagestan. In addition to the group of fields in Southern Dagestan, only one outlet of combustible gas in Central Dagestan is known – the Kulinsky region. It is pointed out in his handwritten report to the Dagestan Economic Council by the geologist N. M. Lednev. This outlet is subordinate to the Jurassic shale and is associated with neotectonic disturbances formed as a result of seismic activation of the region. Aim. The purpose of our research is to substantiate the prospects for gas content in Gorny Dagestan. In the study area, there are irregular dome-shaped folds with unexpected directions of their axes crossing the main direction of folding, partial local deviations in bedding. Methods. The main research methods in the study of the prospects for the gas content of Mountainous Dagestan were geological-structural, stratigraphic, morphological, tectonic and additional aerial photographs. Research results. Compared to Piedmont Dagestan and Prikumskiy region, Gorny Dagestan was subject to more intense geotectonic movements, repeatedly underwent folding, experienced inversion, with a much higher amplitude, which led to increased denudation, the development of fracturing and fractures, metamorphism of rocks and organic formations. All of this negatively affected the conservation of oil and gas. It can be assumed that many deposits, formed during the passage of the producing strata of the main phase of oil formation, were destroyed during periods of intensified tectonic activity at the boundary between the Jurassic and Cretaceous, Cretaceous and Paleogene. In the future, there was the generation of mainly gaseous hydrocarbons, which, under especially favorable conditions, could persist to the present day. According to the research results, it can be argued that the gas manifestation of Tsushar could have manifested itself in 1622, 1652. as a result of strong earthquakes, the epicenter, which was located within the study area


2003 ◽  
Vol 1 ◽  
pp. 527-541 ◽  
Author(s):  
Anders Ahlberg ◽  
Ulf Sivhed ◽  
Mikael Erlström

In Sweden, Jurassic strata are restricted to Skåne and adjacent offshore areas. Jurassic sedimentary rocks predominantly comprise sandy to muddy siliciclastics, with subordinate coal beds and few carbonate-rich beds. During Mesozoic times, block-faulting took place in the Sorgenfrei– Tornquist Zone, a tectonic zone which transects Skåne in a NW–SE direction. The Jurassic depositional environments in Skåne were thus strongly influenced by uplift and downfaulting, and to some extent by volcanism. Consequently, the sedimentary record reveals evidence of numerous transgressions, regressions and breaks in sedimentation. Relative sea-level changes played a significant role in controlling the facies distribution, as deposition mainly took place in coastal plain to shallow shelf environments. The alluvial deposits in Skåne include floodplain palaeosols, autochthonous coals, overbank sandstones, and stream channel pebbly sandstones. Restricted marine strata comprise intertidal heteroliths with mixed freshwater and marine trace fossil assemblages, and intertidal delta distributary channel sandstones. Shallow marine sediments encompass subtidal and shoreface sandstones with herringbone structures, and bioturbated mudstones with tempestite sandstones. Offshore deposits typically comprise extensively bioturbated muddy sandstones. Floral remains, palaeopedology, clay mineralogy and arenite maturity indicate a warm and humid climate in Skåne throughout the Jurassic, possibly with slightly increasing aridity towards the end of the period. Most Jurassic strata in Skåne have been subjected to mild burial diagenesis, and the petroleum generative window has rarely been reached.


Author(s):  
Thomas Vienken ◽  
Manuel Kreck ◽  
Jörg Hausmann ◽  
Ulrike Werban ◽  
Peter Dietrich

Solving complex hydrogeological problems often requires a thorough understanding of (hydro-) geological subsurface conditions. This is especially true for sedimentary deposits with complex architecture, where lithology and/or hydraulic properties can significantly vary over short horizontal and vertical distances. At these sites, a traditional, solely sample-based investigation approach is often not applicable due to limited data accuracy, resolution, and efficiency. Instead, an adapted investigation approach is required that combines exploration technologies of different resolution and investigation scales. This paper aims to demonstrate the feasibility of such a multi-scale approach for the characterization of a test site near the city of Löbnitz, Germany, that is comprised of heterogeneous alluvial deposits. Our focus is on site characterization in terms of lithology and hydraulic properties, as well as on the delineation and characterization of an aggradated oxbow as a typical example of a small scale geological structure.


2012 ◽  
Vol 34 (2) ◽  
pp. 63-72 ◽  
Author(s):  
Joanna Markowska ◽  
Jacek Markowski ◽  
Andrzej Drabiński

Abstract Groundwater table levels in a river valley depend, among other factors, on meteorological and hydrogeological conditions, land use and water levels in watercourses. The primary role of a watercourse is to collect surface and groundwater, and it becomes an infiltrating watercourse at high water levels. Changes in groundwater levels and the range of these changes depend chiefly on the shape, height and duration of the flood wave in the river channel. The assessment of flood wave impact on groundwater was based on long-term measurements of groundwater levels in the Odra valley and observations of water levels in the river channel. Simulations were performed with the use of in-house software FIZ (Filtracja i Zanieczyszczenia; Filtration and Contamination), designed for modelling unsteady water flows within a fully saturated zone. A two-dimensional model with two spatial variables was employed. The process of groundwater flow through a porous medium, non-homogeneous in terms of water permeability, was described with Boussinesq equation. The equation was solved with the use of finite element method. The model was applied to assess groundwater level fluctuations in the Odra valley in the context of actual flood waves on the river. Variations in groundwater table in the valley were analysed in relation to selected actual flood water levels in the Odra in 2001-2003 and 2010. The period from 2001 to 2003 was used to verify the model. A satisfactory agreement between the calculated and the measured values was obtained. Based on simulation calculations, it was proved that flood waves observed in 2010 caused a rise in groundwater table levels in a belt of approximately 1000 metres from the watercourses. It was calculated that at the end of hydrological year 2009/2010, the highest growths, of up to 0.80 m, were observed on piezometers located close to the Odra river channel. The passage of several flood waves on the Odra caused an increase of subsurface retention by 3.0% compared to the initial state.


2020 ◽  
Author(s):  
Omar F. Althuwaynee ◽  
In-Tak Hwang ◽  
Hyuck-jin Park ◽  
Swang-Wan Kim ◽  
Ali Aydda

<p>In 1998, intense rainfall events hit the Pohang state, south west of Korea, which results in highest number of landslides registered in this area (generally the area has a relatively short history of landslide inventorying). The current inventory was digitized using Aerial photographs (lack of photogeological stereoscopic analysis of the aerial images) and coupled with basic field verification (due to limit funding available). Leaving the applied susceptibility maps models performed, using this inventory, with high degree of uncertainty.  Currently a research initiative carried to audit the landslide inventory using freely available aerial photographs and the time tuning function in Google earth for aerial archives. We notice some slopes area covered with deformed forest types that is similar in texture to that seen in digitized locations of landslides inventory. Due to long retune period of similar rainfall event, and with an assumption that the available landslides inventory might not complete. A certain hypothesis of additional investigation including field work to audit the landslides incidents is highly needed. In the current research, we assumed that, some dormant slopes caused by the 1998 event can be reactivated with the current extreme (uncontrolled) uses of slopes by human activities (constructions of real estate’s projects). To that end, a methodology of three main stages were proposed.</p><p>Stage one; Dormant susceptibility map (DSM) coupled with landslide susceptibility map will be produced. Machine learning supervised classification of eXtreme Gradient Boosting algorithms and Ensemble Random Forest, that run on tree-based classification assumption considering only active and dormant landslides as well as stable ground. Stage two; field work needs to be designed by geological and geotechnical experts to collect the doubtful locations by guidance of DSM and consider the new locations as dormant inventory. However, the areas of low dormant susceptibility (or mutual zones with Landslide susceptibility) will be recommended for advanced filed work and soil sampling test to complete the landslides identification of such highly urbanized area. Stage three; knowing the contour depths of diluvial and alluvial deposits can be useful for extracting areas that are more prone to landslides. Especially in the case of a rigid bedrock beneath the diluvial crust. Therefore, reconstructing the Quaternary formation thickness using boreholes repository and then represent the entire study area using CoKriging surface interpolation technique with elevation model. The current research results will provide us a better understanding of landcover stability conditions and their spatial prediction features.</p><div> <div> </div> <div>[email protected]</div> <div>[email protected]</div> </div>


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