Dariusz Brykała

Site-specific sediment responses to climate change during the last 140 years in three varved lakes in Northern Poland

Accurate dating and unambiguous chronological correlation using cryptotephras provide a powerful tool to compare the varved sediment records of the lakes Głęboczek (JG), Czechowskie (JC) and Jelonek (JEL) (north-central Poland). For the last 140 years, micro-facies analyses and µ-XRF element scanning at seasonal resolution, as well as bulk elemental analyses (organic matter, carbonate) at sub-decadal to decadal resolution, were conducted for all three lakes records. All lakes are located in a region with low population density, and therefore, anthropogenic influences are negligible or only minor. The varve chronologies have been established independently for each record and were synchronized with the Askja AD 1875 cryptotephra. Comparison with monthly temperature data since 1870 and daily temperature data since 1951 revealed different responses of lake deposition to recent climate change. Varves are well preserved over the entire 140 years only at JG, while in the JC record two faintly varved intervals are intercalated and in the JEL record two non-varved intervals occur at the base and top of the profiles. These differences likely are due to variations in lake characteristics and their influence on lake-internal responses. JG is the smallest and best wind-sheltered lake, which favours varve preservation. JC’s attenuated sediment responses can likely be linked to lake productivity changes with respect to climate warming. JEL is lacking a direct sedimentological response to the observed temperature increase, which can be linked to lake size and water depth superimposing regional climate changes. Climate changes at the demise of the ‘Little Ice Age’ around 1900 and the recent warming since the 1980s are expressed in sediment proxies in the lakes with different response times and amplitudes. This detailed comparison study on three nearby lakes demonstrates the influence of local parameters such as lake and catchment size and water depth superimposed on more regional climate-driven changes.

Planning a greenway based on an evaluation of visual landscape attractiveness

Abstract The potential for using a standardized landscape evaluation method for planning a greenway in a young glacial area in northern Poland is evaluated in this paper. In the evaluation of visual landscape attractiveness (VLA), we took into account not only its natural but also its cultural components. The cultural components were divided into two groups, i.e. increasing and decreasing VLA scores. The sources of data needed for the evaluation included a Vector Smart Map level 2 (VMap L2), aerial photographs and a field survey. The newly-designated greenway links two landscape parks (which play the role of greenspaces) and runs along numerous lakes, forests, rivers, and objects of cultural heritage. The greenway is composed of existing local roads, allowing a more optimal utilisation of natural and cultural resources of the landscape, primarily those located between the selected greenspaces. Using this application, the idea of sustainable development can be implemented, and the overlapping protected areas will not be subject to devitalisation. The VLA method can facilitate multiple greenway designations in other areas.

Geology, permafrost, and lake level changes as factors initiating landslides on Olkhon Island (Lake Baikal, Siberia)

Permafrost decline, observed in the last few decades as a result of climate change, causes an activation of cryogenic landslide processes. This study on Olkhon Island in Lake Baikal (Eastern Siberia), located within the discontinuous permafrost zone, was aimed to determine how strongly the landslide forms found there are associated with climatic conditions and if they can react to climate change. It was also important to identify which type of landslides in this area is the most sensitive indicator of the observed changes and to what extent they can react to them. For this purpose, landslides were identified, and their morphology, geological structure, and thermal parameters were assessed. The results show that the key process is the increase in thickness of the active layer, partly due to the presence of Miocene lake clays and changes in water level in Lake Baikal.

The use of the temporal oscillation model to assess variability of precipitation

The article presents the variability of precipitation based on the temporal oscillation model. Series of monthly precipitation totals from the years 1955–1980 were used for the analysis. The detailed research referred to the selected 10 measurement stations in central Poland and 17 in southern Poland. Data series from all the measurement stations were verified in terms of their statistical homogeneity. Furthermore, in accordance with the model guidelines, the tendency was assessed. This was followed by calculation of seasonal and accidental oscillations of precipitation. The results were used to present the variability of precipitation in the two areas studied. The measurement stations in southern Poland showed a much higher mean variation of seasonal oscillations of monthly precipitation. Accidental precipitation, however, is much more significant for the total variability of precipitation in southern Poland.