Search Results (2)

Raised bogs of the Baltic type are unique because of their geomorphologic structure and hydrologic conditions. There are about 80 bogs of this type in Poland. All are affected by human impact, and their water circulation patterns are disrupted by artificial outflows. The aim of the study was to show the effects of human impact on water circulation patterns in raised bog on an example of the Wielkie Bagno peat bog. The main work consisted of field studies, during which measurements of groundwater fluctuations, flows at main outflows, and hydrographic mapping were performed. Data on precipitation and evaporation were also obtained from state institutions. Research has shown that fluctuations in groundwater levels in the Wielkie Bagno bog average 78 cm per year (hydrological years 2018–2019) and the bog is in poor condition. This is mainly due to climate change, which manifests itself in too little precipitation in summer and an increase in evaporation, a too dense drainage network causing the lowering of the groundwater level in the peat bog, and the close proximity of a peat mine causing significant drainage of water from the examined peat bog, as well as too large fluctuations of groundwater during the year and in individual months. In some areas, a near-surface layer of the bog was also detected, about 30 cm thick, which is a sign of bog desiccation (especially in summer). Water balance data were used to show that the quantity of water available in the bog is determined by atmospheric precipitation, which is too small in the warm period. As a consequence, there are months with a negative climatic balance. It was also observed that factors such as physical location in different parts of the bog and the degree of degradation also affect water circulation patterns in the study area. At the moment, the most important task in the peat bog is to raise the groundwater level, reduce its fluctuations, and reduce human pressure on the bog. Full article

Understanding processes that affect changes in the coastal zone and the ability to predict these processes in the future depends on the period for which detailed monitoring is carried out and on the type of coast. This paper analyzes a southern fragment of the Baltic coast (30 km), where there has been no anthropogenic impact (Slowinski National Park). The study was carried out covering a time interval of 65 years. Historic and current aerial photographs (orthophotomaps) from the following years: 1951, 1964, 1975, 1984, 1995, 2004, and 2016 were used. Changes in the position of the foredune toe line (FTL) in each years’ images were used. For each time interval (1951–1964, 1964–1975, 1975–1984, 1984–1995, 1995–2004, 2004–2016), the coastal area over which morphodynamic processes (erosion and accumulation) took place was calculated. The calculated RL (reference line)—FTL positions allowed us to determine differences in the shoreline course in subsequent years and to determine the extent of shifts/changes of the coastline in each time period. The study results showed an equilibrium between the processes of accumulation and erosion, proving that the development of the studied natural coastline is balanced. There was only a change in the trend of the characteristics of changes from erosive into accumulative ones and vice versa. Moreover, along the studied coast section, a certain periodicity in the coastline changes can be observed. The intervals where predominant erosion occurs alternate with those when accumulation prevails, and then the cycle repeats. The analysis of historic/current aerial images and orthophotomaps from 1951–2016 indicated that strong storms have a significant impact on the magnitude of change (accumulation/erosion) and the formation of the studied coastline. Full article