Adam Choiński’s research while affiliated with Adam Mickiewicz University in Poznań and other places

This study represents a pioneering effort to analyze the impact of avalanches descending into Morskie Oko from Marchwiczny Gully, the most active avalanche path around the lake. It focuses on catastrophic avalanches that descended from the analyzed gully, as reported in the literature from the 1900s until now. However, only the data collected in recent years, our field studies, combined with modern LIDAR data and GIS-based modeling, allowed us to perform a detailed analysis. The GIS-based approach effectively uses spatial data to address snow avalanche modeling challenges. Although the study area lies within Tatra National Park, no official services carry out systematic avalanche monitoring or measurements. The impact of hazardous events, such as snow avalanches, on the most famous Polish mountain lake, Morskie Oko, has been poorly described in the literature and has yet to be discovered. Therefore, to analyze the selected avalanche parameters, we mainly used our ground and additional aerial photographs taken by local mountain services and related field measurements. Our analysis resulted in figurative estimates of the extent and volume of avalanche snow and its weight, both on the surface of the ice sheet and the part of the avalanche that did not reach the lake’s shore and remained on the slope of Marchwiczny Gully. For example, the values for the mighty avalanche on February 3, 2023, are 23,500 m ³ and 4,700 tons on the ice surface and 20,000 m ³ and 4,000 tons on the slope. It was determined that avalanches that descend onto the studied lake’s surface result in its shallowing. This process occurs because of sedimentation of slope material carried by avalanches, especially during the final phase of ice cover melting. When openings appear in the solid ice cover in spring, floating ice can migrate, driven by wind pressure, and deposit avalanche material in various parts of the lake bottom. Thus, avalanches contributed to the gradual disappearance of the lake.

The Tatra National Park is the most frequently visited national park in Poland. Its most popular tourist trail is the route to Lake Morskie Oko, the second largest lake in the Tatra Mountains, and the best known mountain lake in Poland. The paper is based on results of field observations, and the analysis of literature and statistical data. The ecosystem of Morskie Oko in this paper is defined as the area of the lake’s catchment. The unique character of Morskie Oko is reflected by its recognition by “The Wall Street Journal” as one of five most beautiful lakes in the world. This results in exceptionally high interest of tourists in the lake despite the difficulties reaching the place. It takes walking a nine-kilometre route with a height difference of 420 m. Study results show the annual attendance of the place by more than a million people, whereas the number of tourists per day can exceed 10,000. The tourist traffic evidently intensifies between June and September. It results in high human pressure on the lake’s waters and surroundings, leading to the degradation of most components of the natural environment. Such high traffic intensity is frequently a nuisance for tourists using the trails themselves. Moreover, high tourist traffic contributes to the intensification of slope processes, resulting in mass movements in the form of debris and snow avalanches, potentially changing the course of the trails.

Lake pollution has attracted concerns worldwide; especially the excessive accumulation of trace elements (TEs) and rare earth elements (REEs) in bottom sediments can pose a serious threat to ecosystem health. However, there is still a knowledge gap on the level of sediment pollution in lakes isolated from the direct impact of pollution sources, their spatial variability, and also on the factors influencing this state. The aim of this study is to investigate the level and spatial variability of TEs and REEs concentrations, as well as to determine their source and the factors determining their distribution in the bottom sediments of Lake Ostrowite. Lake Ostrowite is the largest and deepest water body located in the Bory Tuholskie National Park (in northern Poland), which completely isolates the lake from the direct impact of pollution sources. The study covered analyses of 32 surface samples of bottom sediments. The concentrations of 24 TEs and 14 REEs were determined using inductively coupled plasma mass spectrometry (ICP‐QQQ‐MS). The assessment of the enrichment of bottom sediments in TEs and REEs employed geochemical background values (GBV) that provided the basis for the calculation of relative concentrations and geochemical indices. The determination of their sources and supply routes was based on the cluster analysis and principal component analysis. The obtained results point to the enrichment of the bottom sediments with TEs and REEs. Relative concentration values of TEs and REEs in reference to geochemical background values were in ranges from 0.01 to 7.31, at an average of 0.99, and from 0.03 to 4.29, averaging 1.76, respectively. The enrichment factor values show moderately severe enrichment of sediments at the study sites. This was primarily determined by the concentrations of Ag (from the TEs group) and Lu (from the REEs group). The metal pollution index values showed an approximate spatial distribution of points in terms of the presence of TEs and REEs. The lowest concentrations of TEs and REEs occurred on the eastern shore of the western basin of Lake Ostrowite. TEs and REEs concentrations in sediments are positively correlated with the content of organic matter and depth and negatively correlated with distance of the sampling point from the river outflow from Lake Ostrowite. On the eastern shore of the western basin, TEs and REEs concentrations are additionally shaped by wind, predominantly from the western direction. With water wave action, organic matter is transported to the central part of the western basin, where it is accumulated. Since the lake is isolated from point and nonpoint pollution sources, relevant from a biogeochemical point of view are dry and wet depositions from the atmosphere as well as aquatic vegetation, shoreline vegetation, forest litter, soil, and groundwater.

Оцінювання динаміки озерних систем є досить складним завданням. Це зумовлено тим, що водоймам як компонентам природного ландшафту властиво швидко й чутливо реагувати на зміну свого середовища. Будь-яке порушення вже сформованих екосередовищних умов у межах водозбору обов’язково позначається на водному режимі водойм. У сукупності впливу багатьох чинників велика кількість озер Польщі та України значно змінили свої природні параметри. Процесам замулення, обміління, зменшенням об’єму води та площі водного дзеркала піддаються майже всі озера й навіть водойми в межах природоохоронних територій. Дослідження охопили територію Великопольської низовини Польщі та Волинського Полісся України, які характеризується наявністю значної кількості льодовикових озер. Метою проведеної роботи є оцінка ступеня заростання та зникнення озер у Поморському, Мазурському та Великопольському поозер’ях, а також у Волинському Поліссі України. Дослідження базувалися на аналізі поверхні озер і ділянок, які заросли емерійною рослинністю. Відправною точкою були матеріали, розроблені на основі документації, підготовленої Інститутом внутрішнього рибальства в Ольштині в 1958‒1968 роках. Їх порівнювали з даними, отриманими з ортофотопланів Центрального відділу геодезичної та картографічної інформації Польщі за 2010‒2012 рр. Oкрім того, відібрані об’єкти проаналізовано за ортофотопланами 2020‒2022 років. Для оцінки лімнодинаміки волинських озер використано показники, наведені в працях польських озерознавців 1930-х років, матеріали Геологічного фонду України, Регіонального офісу водних ресурсів Волинської області, супутникові фотографії та власні експедиційні дослідження.

The aim of the study is to determine the scale of differentiation and variability of ice phenomena on the lakes in the south-eastern part of the Baltic Sea catchment area. The analysis was performed based on data from the period 1961–2020 from 15 lakes located in Poland (10) and Belarus (5). The characteristics of ice phenomena were characterized, i.e., the length of their occurrence and ice cover, the thickness of ice cover and the number of breaks occurring in the ice cover in the given years were characterized. The analysis of the course of ice phenomena made it possible to distinguish three regions with an increasing length of ice phenomenon occurrence from west to east. The zones were the west of the Vistula, the east of it and the eastern part of the Belarusian Lake District. In the analyzed multi-year period, a shortening of the duration of ice phenomena and ice cover, a decrease in the maximum thickness of the ice and an increasing number of breaks in ice cover were observed. These data correlate with the upward trend in air temperature.

This dissertation has presented the results of measurements regarding the surface area of Morskie Oko and Wielki Staw lakes performed throughout the period of 140-years with the use of various measurement technologies and analyses of cartographic resources. The research has clearly demonstrated that the obtained results are diverse, which could be influenced by various environmental factors and the time difference of surveys conducted at the ana- lysed objects. Wielki Staw is currently the largest lake in the Polish Tatra Mountains. Its surface area in 2021 covered 33.44 ha. Thus, it appeared to be larger than Morskie Oko, the surface area of which is 1.51 ha. It was also concluded that the difference in the size of these two reservoirs might increase over time since Morskie Oko is situated in an environment that undergoes dynamic transformations and, consequently, has an impact on the evolution of this lake. Moreover, the area surrounding Morskie Oko is one of the most popular tourist locations within the Tatra National Park, which may intensify the anthropogenic impact on the course of, among others, the shoreline.

On the basis analysis of 53 hydrographic maps in the scale 1:50,000, an inventory of crenological objects in the Świętokrzyskie Voivodeship was made. A total of 462 of them were identyfied. Most of them are permanent springs, precisely 346, followed by: 60 permanent springs with intakes, then 34 periodic springs, 10 spring groups, 5 bog springs, 3 mineral springs, 3 observed springs and 1 other outflow. Moreover, the studies revealed the diversity and specificity of the region in terms of crenology. Total discharge of all springs is small as it was estimated at 459.04 dm3•s–1. The most efficient springs reach about 40 dm3•s–1 and only eight exceed 20 dm3•s–1. The total discharge of the 10 most efficient outflows amount to 258.6 dm3 s-1, which accounts for 56.3% of the output in the Świętokrzyskie Voivodeship. In terms of the number of crenological objects, there is a clear difference between the mountain and highland identyfied. In the area of the Świętokrzyski National Park, 25 outflows were registered. Their total output is 6.5 dm3•s–1. At the same time, on the northern slopes of the Świętokrzyski National Park, 21 crenological objects with a total discharge of 5.5 dm3•s–1 were identyfied.

High montain lakes are regarded as sensitive indicators of environmental changes in local and global scales. In recent years, climate change has considerablely influenced the timing of ice phenomena in these lakes. The objective of the paper is an investigation of long-term changes and periodicity of ice phenomena in high mountain Lake Morskie Oko (1392.8 m a.s.l.) located in the Tatra Mts. in the period 1971–2020. The study employed the Lomb-Scargle periodogram, linear regression modelling for temporal trends, correlation analysis, parameters of variability, and flashiness index. Periodicity of the duration of ice phenomena (∼5.4 y) and ice cover on the lake (∼13.5 y) was observed, although both are statistically insignificant. Ice cover duration has been interrupted several times by winter thaws after 1996 whereas no such events had been reported earlier. The trend towards a delayed appearance of ice phenomena reaches 4.0 d·decade−1 (p < 0.001). The observed trend towards an earlier ice phenomena disappearance reaches 5.1 d·decade−1 (p < 0.001). It results in a decline of the number of days with ice phenomena on Lake Morskie Oko at a rate of 9.0 d·decade−1 (p < 0.001). The duration of ice cover on Lake Morskie Oko has been decreasing at a rate of 10.4 d·decade−1. It is attributed to later freeze-up (3.9 d·decade−1, p < 0.001) and earlier ice break-up (5.6 d·decade−1, p < 0.001). An increasing trend of average annual air temperature (0.4°C·decade−1, p < 0.001) in the period 1971–2020 is observed. A statistically significant correlation is recorded between ice phenomena and ice cover (beginning, end, duration), average annual air temperature, average air temperature of three summer months (June, July, August), and average air temperature of the six months period from June to November. Higher air temperature induces growing heat resources accumulated in the lake water in the summer and autumn seasons, potentially causing later initiation of ice phenomena in the lake. There is no statistically significant relationship between maximum ice thickness and any air temperature parameters. Variability of maximum ice thickness appears to have been significantly increasing in the second part of the investigated period (1996–2020).

The paper presents changes in the surface area and overgrowing of the largest Polish lakes (> 500 ha). It has been established (on the basis of 4 analyzed time sequences) that over the last 80 years there has been a gradual reduction of the lake area. At the same time, the area occupied by emerged vegetation has increased. This is confirmed by the lake overgrowth rate and the shoreline overgrowth rate.

The paper presents an assessment of water level fluctuations in eight lakes located in the Bory Tucholskie National Park (Poland). Mann-Kendall and Sen tests were applied to analyze the extent and direction of lake water level changes. For the purpose of detection of shoreline active zones, digital lake bottom models were developed based on bathymetric measurements. They were integrated with catchment digital terrain model, developed based on data from Airborne Laser Scanning. In analysed period, water levels in the majority of lakes showed a decreasing tendency, as a result of climate change. An increasing tendency was only observed for two lakes caused by the activity of beavers (castor fiber). The study permitted the identification of active shoreline zones with long-term exposure to drying and flooding. These zones are of the highest importance from the point of view of the functioning of water and water-dependent ecosystems, particularly protected species.