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Changes in habitat conditions in a Late Glacial fluviogenic lake in response to climatic fluctuations (Warta River valley, central Poland)

Forysiak Jacek, Okupny Daniel, Obremska Milena, Antczak-Orlewska Olga, Płóciennik Mateusz, Pawłowski Dominik, Baradyn Daria, Kotrys Bartosz, Luoto Tomi P., Nevalainen Liisa, Borówka Ryszard K.

Geological Quarterly

2023

Vol. 67, No. 1

art. no. 1

The Warta River valley was greatly influenced by the ice sheet of the Last Glacial Maximum (LGM). A small peatland located in the Warta drainage system is here used as a palaeoarchive of climatic and habitat changes during the Late Glacial (Weichselian). The Ługi sediment profile was investigated using multi-proxy (pollen, Chironomidae, Cladocera and geochemistry) analyses that recorded changes in a fluviogenic sedimentary depression. After the Poznań Phase (LGM), Ługi functioned as an oxbow lake that was cut off from the active river channel as a result of fluvial erosion. Since that time, the Warta River has flowed only along the section now occupied by the Jeziorsko Reservoir. Sedimentation of lacustrine deposits started at the beginning of the Late Glacial. Summer temperature reconstructions indicate cool Oldest and Younger Dryas, but no clear cooling in the Older Dryas. During the Younger Dryas the palaeolake was completely occupied by a peatland (fen), which periodically dried out during the Holocene. Investigation of this site has tracked the reaction of the habitat to climatic, hydrological and geomorphological changes throughout the Late Weichselian.

Development of Channel Processes and the Need to Forecast Deformations of the Stryi Riverbed

Hnativ Ihor, Balkovskyi Volodymyr, Cherniuk Volodymyr, Panas Natalia, Korinec Yuri, Yakhno Oleh, Hnativ Roman

Journal of Ecological Engineering

2022

Vol. 23, nr 5

187--195

Deformations of the channel are a consequence of the development of denudation processes in the basin area, increase in the volume of solid runoff and deposition of debris of the rock, its fractional redistribution in the channels, which especially increase during floods and flooding. They cause changes in the hydrological regime and structure of the river system, the destruction of residential and commercial buildings, as well as the infrastructure in the floodplain. Trends, magnitudes and intensity of deformations of riverbeds are formed by a complex of natural and man-made factors. Neglecting the planned and high-altitude displacements of riverbeds often leads to unpredictable consequences. Washing the shore can cause a gas or oil pipeline to rupture, leading to a strong explosion and fire, as well as oil pollution and environmental damage. Channel processes are associated with the washing of bridge piers, power lines, significant material losses and even human casualties during floods and flooding. The aim of the work is to analyze the development of channel processes in the basin of the river Stryi and forecast the deformation of its channel. The results of the analysis show that the riverbeds of Prykarpattia are very unstable and are characterized by intense erosion of the banks and bottom, which is caused by the influence of various factors. It is a man-made activity that includes the development of gravel quarries in floodplains and riverbeds and their straightening, runoff regulation, changes in forestry and land use. Natural factors, such as climate change and water runoff, etc., are also affected. It was found that the bed of the river Stryi does not have a stable shape, significantly changed the configuration, significantly reduced multi-sleeved and increased its straightness, and in some places the river changed its position by 60–80 meters. Restoration works carried out in some parts of the riverbed during this period were not effective enough. Water in different parts of the riverbed washes the shores, which causes dangerous landslides that occur directly near the riverbed. In these areas, it is necessary to more effectively carry out measures to regulate runoff and restore shore protection.

Wpływ procesów denudacji na właściwości osadów wypełniających zagłębienia między krętymi wałami z erozji wód subglacjalnych w okolicy Zbójna (Pojezierze Dobrzyńskie)

Karasiewicz M. T., Hulisz P., Świtoniak M.

Landform Analysis

2013

Vol. 25

29--42

Badania prowadzono w obrębie pola testowego o powierzchni 1 km2 w okolicy Zbójna (Pojezierze Dobrzyńskie). Ich celem była anali- za wpływu denudacji (naturalnej i antropogenicznej) na właściwości osadów zagłębień występujących między formami wypukłymi (krętymi wałami z erozji wód subglacjalnych). Wyróżniono pięć typów wypełnień badanych zagłębień. Badania wykazały, że występująca w nich specyficzna sekwencja osadów ma wyraźny związek zarówno z procesami naturalnymi, jak i z intensywną działalnością rolniczą prowadzoną od wieloleci na tym obszarze. Stopień i zasięg przekształceń był w znacznym stopniu uzależniony od cech morfometrycznych tych zagłębień. W porównaniu z osadami budującymi grzbiet krętego wału z erozji wód subglacjalnych, osady analizowanych zagłębień charakteryzowały się wyraźnie odmiennym chemizmem, który nie- wątpliwie wskazywał na ich funkcjonowanie jako pułapek sedymentacyjnych.

The research was conducted within a test field of 1 km2 located near Zbójno, that lies in the south-eastern part of the Dobrzyń Lakeland. The objective of the research was to analyze the effect of natural and anthropogenic denudation on the properties of sediments in depressions between glacial curvilineations. Five types of deposits were identified in the studied depressions. These depressions are filled with sediments sequences which are closely associated with natural processes and long-term extensive farming. The degree and the range of transformations of deposits and depressions depend largely on their morphometric characteristics of these depressions. Compared with sediments building the ridge of a glacial curvilineation, the deposits of the analysed depressions were characterised by significantly different chemical composition, which clearly indicates their function as sediment traps.