Search

[Display omitted] • The effect of data record length on environmental flow calculation is presented. • Method 7Q10 is the less sensitive to environmental flow calculations. • Trend analysis should be the starting point for calculation of environmental flows. • Environmental flows have a significant impact on water resource availability. • Environmental flows are the starting point for sustainable water management. The paper presents the analysis of problems regarding the calculation of EFs using selected hydrological methods. It was conducted in 14 catchments in the Vistula and Oder River basins in Poland. The Kostrzewa, Tennant, Q 90% , and 7Q10 methods were used for the analysis. The analysis showed a significant trend in the hydrological time series. The sensitivity of different applied methods to time series length was shown. High differences were observed between environmental flow (EF) values calculated for periods defined by break points. The hydrological drought and its impact for EFs were also observed for half years in the period. Finally, different values of water deficit characteristics were presented depending on the method used for EF calculation. [ABSTRACT FROM AUTHOR]

• The flood flow course in lowland areas may be influenced by valley geology. • The floodplain relief testifies influence of the valley geology on fluvial processes. • The sub-alluvial bedrock protrusions favour the creation of ice jams. • In the light of climate changes the bedrock impact on river behaviour will increase. In this paper, we analyse the significance of alluvial substrates in shaping the morphodynamics of the bottom of a lowland river valley. The research focus was a 20-km reach of the Bug River valley, an example of a large river in the Polish Lowlands. There are no anthropogenic elements in the valley that can disturb the course of natural river processes. The Bug River channel has not been engineered in the section analysed. Eighty-one geological drillings performed in the channel allowed identification of 11 zones of sub-alluvial bedrock protrusions built up from erosion-resistant deposits. The determination of the valley bottom surface morphology was based on high-resolution multispectral satellite images in natural and near-infrared colours. Geological and geomorphological mapping of the valley bottom surface were also carried out. The obtained results showed that the key factors controlling the morphodynamics of this floodplain are protrusions of sub-alluvial bedrock. Under medium- and low-flow conditions, these are hidden under a layer of channel deposits. However, during high flows, the surface of the protrusions is exposed, affecting the pattern of flood flows and forcing them to enter the floodplain in certain, recurrent zones. The result of such phenomenon is the creation of characteristic sets of accumulative and erosive landforms. Thirteen types of such forms have been identified. The presence of sub-alluvial bedrock protrusions in this river channel has promoted formation and persistence of ice jams (confirmed by analysis of hydrograms from 1969 to 2018). The case presented in this paper shows that the certain arrangement of landforms indicate morphodynamic specificity of valley bottom whose alluvial substratum exerts an influence on flood flows. Since protrusions of alluvial substrate is associated with glacial genesis of the area cut by the Bug River, the described phenomenon may also occur in other postglacial areas. [ABSTRACT FROM AUTHOR]

The unfavourable environmental conditions to Chernozem development in Central Europe has led to questions regarding their origin and age, and conditions necessary for Chernozem persistence in Central Europe under a humid climate. This paper deals with Chernozem transformation during the Holocene period in SW Poland in relation to land morphology. The study was based on a catenary approach, with additional remarks on parent material homogeneity and soil classification. Based on textural and geochemical indices, the homogeneity of aeolian material (loess) was proven in the main part of the catena, which confirmed that the differentiation of “dry” and “wet” chernozemic soil across the catena did not result from the variability of parent material. No differences in morphological or physicochemical characteristics of mollic horizons were identified between the well-drained and wet sections of the catena. The strong redoximorphic features (manifested as stagnic or gleyic properties) in the lowermost part of catena are, therefore, secondary features, i.e. developed after the mollic horizon development, presumably in late Holocene period. Chernozems with chernic horizon, weakly developed subsurface argic horizon and free of redoximorphic features prevail in the central, well-drained and not eroded section of the catena. It has been hypothesized that the loess soils in the uppermost, more inclined part of the catena have been truncated by erosion during the first agricultural period, then afforested and transformed into Luvisols, probably due to temporary abandonment of those sites less favourable for farming. The soils in the transitional zone received the colluvial addition of humus material from the eroded hill summit; however, the colour of the humus layer has a chroma too high for a chernic horizon that surprisingly shifted these soils to the Kastanozems group. This study showed that the direction of transformation of native Chernozems in the Holocene period was strongly related to their position in the landscape, which affected the erosion/accumulation intensity and water drainage conditions (soil moisture regime). As a final result of these transformations, a relief-related zonality of soils has developed with Stagnic/Gleyic Chernozems – Luvic Chernozems – colluvial “Kastanozems” – Haplic Luvisols, in the lower (moist), middle (well-drained), and upper colluvial/eroded sections of the undulating loess plain, respectively. [ABSTRACT FROM AUTHOR]

The paper discusses results of sedimentological, faunal (molluscs, ostracods) and geochemical studies of an 80-cm-thick rhythmite succession within a glaciolacustrine sequence (8–10 m in thickness) of the Ławki Formation exposed at the Parchliny C site, in the tectonically active Kleszczów Graben, central Poland. Sedimentological studies show the predominance of rhythmically deposited pale grey muds (2.0–7 cm thick) and black clays (0.5–5 cm thick). The pro-glacial sediments have yielded the first examples of Saalian molluscan and ostracod communities to be recorded from Europe and probably globally. The presence of a lake basin is confirmed by the freshwater species fauna: Candona neglecta , Cypridopsis vidua , Fabaeformiscandona protzi , Limnocythere inopinata , Limnocytherina sanctiparicii Cyclocypris laevis , Metacypris cordata (ostracods) and Anodonta cygnaea , Ancylus fluviatilis , Theodoxus fluviatilis , Bithynia tentaculata , Valvata piscinalis and Pisidium sp. (molluscs), suggestive of deposition during a period of colder climatic conditions, although some species might be indicative of a warmer period, resembling an interglacial. The whole section has a high carbonate content, up to several tens percent. The carbonates are enriched in the heavy isotope of oxygen. The isotopic composition of carbon and oxygen indicates two stages of lake development. The transition of the lake from a hydrologically open to a closed system with significant evaporation has been reconstructed from correlation of δ 13 C and δ 18 O. Sedimentological, faunal (molluscs, ostracods) and stable-isotope studies of the Saalian Ławki Formation have revealed an important snapshot – a 14-year record in the hydrological transformation of this specific pro-glacial lake system. [ABSTRACT FROM AUTHOR]

• Recent geochronological findings are not engaged, leading to a different conclusion. • Alluviation during ca. 26–11 ka is not supported by radiocarbon dates. • Interpretation of some sediments and processes should be reconsidered. In a study where one of the objectives was to assess the impact of climate change on evolution of an alluvial fan, the authors determined some geochronological data that enabled them to discuss paleoenvironmental conditions of the Czarny Dunajec River system. They conclude that the gravelly material stored in the fan was deposited probably between c. 27 and 14 ka BP, MIS 2, and link this period of deposition with the glacier development in the Tatra Mountains. The geochronological data presented in their paper, however, does not support largely this statement, also the discussion does not take into account the newest findings in the region, which disprove the presumed connection between alluvium deposition and glacial stages. Additionally, some data on river terraces and alluvial sediments requires clarification, i.e. number of terraces and their heights, straths and the composition of terrace deposits, and the processes from which sediments and the fan originate. [ABSTRACT FROM AUTHOR]

Buried, humus-rich horizons, up to 0.60 m thick, poor in archaeological artefacts and other anthropogenic materials, were identified during an archaeological rescue excavation conducted at monastery grounds, located near the centre of Wrocław (SW Poland). As indicated by historical sources, the monks settled in the 18th century in a suburb area, which had been used for agriculture and gardening since the Middle Ages. The paper discusses the origin of the thick humus horizon in the context of various concepts of ‘Dark earths’ formation. Three hypotheses were considered, linking the soil formation with: 1) natural pedogenesis in alluvial material, 2) ancient settlement and human activity resulting in accumulation of materials, and 3) past/modern agricultural and horticultural activities. In order to reveal the origin of this humus-rich horizon, and investigate the possible involvement of anthropogenic factors in its creation, an interdisciplinary research protocol was adopted, which involved a historical query and archaeobotanical, micromorphological, and physico-chemical soil analyses. It was argued that the studied soil, poor in archaeological artefacts, is in fact a relatively young anthropogenic soil, which had been formed by triple- and double-depth digging (Rigosol) and enrichment of the soil in certain kinds of anthropogenic material (Anthrosol), but without surface up-building typical for soils with Plaggic and Terric horizons. This led to a transformation of the original soil cover, increasing the thickness of its A horizon and adapting it for supporting gardens and orchards. These practices, which most likely took place in the late medieval and modern era period up to the 19th century, have been completely forgotten until now. In this light the discovered Rigosol-Anthrosol may be considered an artefact of horticultural/agricultural land use in the former suburbs, which were absorbed by the rapidly growing city during the last century. It is also postulated, that Rigosols (–Anthrosols) may be widespread among Dark earths in some medieval suburban and present-day urbanized areas of cities and should be investigated during archaeological research. [ABSTRACT FROM AUTHOR]

Models of geomorphic evolution of tablelands vary as far as the patterns of cliff line degradation and hence, scarp retreat are concerned. Among surface processes rock slope failures from caprock cliffs, often induced by preferential seepage from rock faces, are emphasized. In this paper evidence is provided that mechanical removal of sand from inside the caprock through underground erosion may also play an important role in the long-term evolution of cliffed escarpments in sandstone tablelands. More than 140 sandy cones and nearly 80 sand sheets emerging from fissures in the sandstone cap were mapped and measured along six cliff sections of variable length in the Stołowe Mountains tableland in SW Poland. The density of sandy accumulation forms varies along the cliff length, with cones preferentially associated with intact cliffs and sand sheets being more common along degraded cliff sections. Further redistribution of sand downslope results in widespread sandy covers below cliff lines which extend for a few hundred metres and are 1–3 m thick, as demonstrated by electrical resistivity tomography. Sand removal from caprock accounts for progressive, non-catastrophic degradation of tableland margins through gradual subsidence of blocky compartments and the development of ruiniform relief behind the cliff lines. Thus, it may be an important component of long-term evolution of stepped relief in sedimentary terrains. [ABSTRACT FROM AUTHOR]

Abstract: Human-induced erosion is one of the key factors leading to the soil degradation. Agricultural, undulating or hilly morainic areas of North-Eastern Poland are exposed to this negative process. This paper elucidates the influence of accelerated soil erosion on soil cover in young morainic landscapes of North-Eastern Poland (Brodnica Lake District). Detailed pedological investigation (21 soil pits and 375 augerholes) were carried out within two study sites (forest and agricultural). A comparison of fully developed forest reference soil pedons with arable soil has been made. Five classes of soil truncation have been distinguished. According to the identified degrees of truncation, maps of soil cover transformation, caused by accelerated erosion, were generated and overlapped on Digital Elevation Models (DEMs). Eroded soils overlap 39.5% of agricultural area and 2.5% of forest site. The widespread occurrence of strongly and completely eroded pedons (respectively 7.4% and 5.4%), only in the agricultural areas, provides intense anthropogenic impact on soil cover in the agriculture areas of North-Eastern Poland. The average values of soil reduction are about 40–50cm. In the case of completely eroded soils it exceeds even 100cm. Truncation of pedons with abrupt textural change due to the slope processes leads to the disappearance of vertical textural contrasts and the formation of new soil units. The evidence of erosion from the topsoils is mainly the decrease in the content of organic matter and calcium carbonate enrichment. The effect of intensive slope processes is widespread occurrence of thick (up to 3m) colluvial deposits. [Copyright &y& Elsevier]

• We reconstructed environment changes with the use of multi-proxy approach. • Permafrost degradation led to a radical transformation in the flow of groundwater. • The paludification of the basins was determined by local conditions. • The process of subsidence determined the characteristics of the sedimentation basins. The paper presents records of lithofacial succession in the sediments of the Bagno Staw alkaline fen (Western Polesie Lowland, Eastern Poland), documenting the phase of rapid morphogenetic transformations during LG/H in the Lublin chalkland. Environmental conditions responsible for the morphogenesis and evolution of the site (from a shallow periglacial lake to an alkaline fen) were reconstructed. A detailed geological survey in combination with the analysis of Cladocera assemblages revealed the presence of numerous palaeodepressions under the plain covered today by the alkaline fen, which were initially small shallow lakes with a well-developed phytolittoral zone. Geochemical data and the analysis of stable O and C isotopes indicated that these lakes were supplied by ascending waters. Karstic phenomena under periglacial conditions, including subsidence at the bottom of biogenic accumulation basins, played an important role in the transformation of this site. These changes were largely determined by the chronology and dynamics of permafrost degradation. [ABSTRACT FROM AUTHOR]

• We reconstructed environment changes with the use of multi-proxy approach. • Permafrost degradation led to a radical transformation in the flow of groundwater. • The paludification of the basins was determined by local conditions. • The process of subsidence determined the characteristics of the sedimentation basins. The paper presents records of lithofacial succession in the sediments of the Bagno Staw alkaline fen (Western Polesie Lowland, Eastern Poland), documenting the phase of rapid morphogenetic transformations during LG/H in the Lublin chalkland. Environmental conditions responsible for the morphogenesis and evolution of the site (from a shallow periglacial lake to an alkaline fen) were reconstructed. A detailed geological survey in combination with the analysis of Cladocera assemblages revealed the presence of numerous palaeodepressions under the plain covered today by the alkaline fen, which were initially small shallow lakes with a well-developed phytolittoral zone. Geochemical data and the analysis of stable O and C isotopes indicated that these lakes were supplied by ascending waters. Karstic phenomena under periglacial conditions, including subsidence at the bottom of biogenic accumulation basins, played an important role in the transformation of this site. These changes were largely determined by the chronology and dynamics of permafrost degradation. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the results of 40years of research on the gully system in the Doły Podmularskie catchment (0.35km² in size), which is situated in the south-western part of the loess-covered Nałęczów Plateau in SE-Poland. Topographic, stratigraphic and pedologic investigations, and monitoring of a tributary gully (gully area: 0.7ha, catchment: 2.5ha) were combined with historical, archaeological and palaeoecological records. The results reveal a long and complex history in terms of the temporal and spatial extent and the impact of land use on gully erosion, and the long-term feed-back mechanisms between land use changes and natural processes since the end of the Pleistocene. Phases of gully erosion and subsequent filling occurred in the Bronze Age and around the 10th to 11th centuries. The most severe deepening and expansion of the gully took place in the 17th century. The results also show that field structures and land use intensity had a significant influence on the frequency and magnitude of run-off, soil erosion, piping, and landslide events. The last significant erosion phase started in the mid-19th century with renewed headward retreat and down-cutting within older gully fills. Today, most of the catchment is either forested or the land is covered in berry shrubs. In the future, the area will continue to produce sediments, because of the steep slopes and because there are still areas of bare soil with a low resistance to erosion, a legacy from past land uses, which will remain a factor affecting soil erosion and sedimentation processes in the future. This study is an example of how important it is to observe and understand slow geomorphologic processes and rare extreme events in the light of land use changes when investigating long-term human–environment interactions. [Copyright &y& Elsevier]

Abstract: Landslides are common in the Polish part of the Flysch Carpathians. They are controlled mostly by lithology and tectonics of the bedrock and by climate. They are a major factor of slope transformation. Rock cliffs within deep landslides are overgrown with lichen thalli of the Rhizocarpon genus, so these cliffs may be dated using lichenometry. This paper presents the basics of lichenometry as well as its applications in geomorphological research in Poland and worldwide. Also presented are results of lichenometric dating of landslide–rockfall walls in the western part of the Polish Flysch Carpathians. The study helps to identify landslide episodes from historical times. The results obtained indicate that on the slopes studied there coexist several generations of landslide–rockfall forms of various age, including recent and active ones. [Copyright &y& Elsevier]

• The ratio of the CH 4 production paths in freshwater sediments changes with depth. • The quality of organic matter is main controlling factor of the CH 4 production pathways. • The incompletely degraded organic matter favours hydrogenotrophic methanogenesis. • Higher contents of labile organic matter favours acetoclastic methanogenesis. The paper presents the research results on methane production (CH 4) pathways in freshwater sediments of the Nielisz Reservoir located in south-eastern Poland. The research was performed in spring, summer and autumn 2018 at four research stations located along the reservoir and in three sediments layers: 0–5 cm, 5–10 cm and 10–15 cm. The values of δ13C-CH 4 in pore water, the fractionation coefficient α CH4-CO2 , and the δ13C isotope mass balance of pore water CH 4 and CO 2 were used to determine the temporal and spatial changes of CH 4 production pathways. The obtained values of δ13C-CH 4 in the pore water of the Nielisz Reservoir ranged from −68.40‰ to −50.87‰, the α CH4-CO2 values varied from 1.04 to 1.07, and the calculated contributions of hydrogenotrophic methanogenesis in the total production of CH 4 (f CH4,h) ranged from 7% to 85%. These values varied depending on the research station and the sediment layer studied. During the entire study period, both acetate and hydrogenotrophic methanogenesis participated in CH 4 and the contribution of hydrogenotrophic methanogenesis increases in the deeper layers of sediment and in the autumn season. The main controlling factor of CH 4 production pathways in sediments is the qualitative composition of organic matter (content of labile organic matter and humic substances). [ABSTRACT FROM AUTHOR]

• Lake sediment-derived environmental reconstruction is presented for the 4.2 ka event. • Summer temperatures and climate humidity remained stable during the event. • We found likely indication of more severe winters between 4.0 and 4.25 ka BP. • A pulse of podzolization, likely favored by winter cooling, was reported ~4.2 ka BP. • The terrestrial vegetation and the lake biota remained unaffected by the event. Many regions around the world experienced abrupt climate change with far-reaching societal and environmental effects at ca. 4.2 cal. ka BP. As one of the most distinct climatic events of the last 11.7 ka, it has been used to establish the formal boundary between the mid- and late-Holocene. Although the 4.2 ka event was not pronounced in East-Central Europe, its exact impact on the area has yet to be evaluated. The aim of this paper is twofold: (1) to reconstruct the functioning of the selected lake and terrestrial ecosystems from northern Poland around the time of the 4.2 ka event, and (2) to disentangle the drivers of the recorded environmental changes (local factors vs. climate impact). We studied the sedimentary record of Lake Spore, focusing on the period between 3.8 and 4.5 cal. ka BP using numerous biotic and abiotic proxies, such as chironomids, cladocerans, pollen and spores, δ13C org , δ15N org , δ18O carb , δ13C carb , TOC/N, Fe, S, LOI 550 , and LOI 950. The chironomid-derived reconstruction of mean July air temperature did not change during the 4.2 ka event. Pollen accumulation rate (PAR) data showed lower pollen production of some tree taxa during the period 4.0–4.25 cal. ka BP that is consistent with low PARs recorded for the corresponding period in the sediments of nearby (~75 km) Lake Suminko. This change might have occurred due to either regional-scale forest disturbance or cooler winters resulting from an exceptionally strong Siberian High during the 4.2 ka event. Distinct peaks of Fe and δ13C carb at 4.2 cal. ka BP likely record a pulse of podzolization. Although soil transformation processes were common in East-Central Europe after ca. 5 cal. ka BP due to general climate cooling, they could have been enhanced at Lake Spore during the 4.2 ka event, if winters were more severe. The δ13C org , δ15N org , TOC/N and δ18O carb records point to a water level rise after 4.2 cal. ka BP that most likely resulted from soil transformation in the catchment, not a change in effective precipitation. The composition of the terrestrial vegetation and the lake fauna and flora remained largely unaffected by the 4.2 ka event. [ABSTRACT FROM AUTHOR]