The aim of this article is to determine the share of frost processes in the annual balance of river bank erosion. Rates of erosional retreat of river banks in Podhale (boundary zone between the Central and Outer Carpathians) were measured for the hydrological year 2013–2014. Bank erosion during the winter half year was caused mainly by frost phenomena (ground ice and needle ice) and during the summer half year – by fluvial processes and mass movements (undercutting, slumping). The share of erosion by fluvial processes in the yearly progress of bank retreat (this amounted to 71 cm on average) was four times greater than by frost processes, including mass movements. The effects of erosion by frost processes were greatest in the upper parts of banks, built mostly of fine-grained alluvia, while the lower parts, built largely of gravel, were mostly eroded by fluvial processes.

The paper presents the possibilities of the airborne laser scanning (ALS) data use in the morphological analysis of the bottom of the designed Pietraszki multi-purpose water reservoir, which is located in the mouth section of the Sufraganiec river (5th rank) in Kielce. The source material consisted of 0.5 m resolution digital terrain model created by the MGGP Aero company on the base of ALS point cloud obtained in 2011. The analysis was performed in SAGA GIS software and included modelling of the Sufraaniec valley bottom, where the reservoir’s coastline was outlined, and a calculation of the reservoir’s geometrical and morphological parameters. A practical effect of the analysis was the estimation of the ground masses volume that need to be moved in the investment area and also the designation of recreational zones along the reservoir’s coastline. The performed analysis demonstrates the legitimacy of ALS digital terrain model use in detailed modelling of the planned reservoir bottom and also in outlining its coastline reach at the designed water levels.

The objective of the study was the long-term and annual variability of atmospheric circulation indices over the Lublin region in the years 1951–2010. The zonal, meridional and cyclonicity indices were calculated based on the calendar of circulation types over East-Central Poland. Furthermore, the relationships between atmospheric circulation and thermal as well as precipitation conditions in the Lublin region were examined. In winter season, the strongest zonal circulation was noticed in the period from the second half of the 1980s to the end of the 20th century. In the last two decades of the analyzed period, a higher frequency of southern circulation in summer was observed. The characteristic features of atmospheric circulation in the study area include the prevalence of westerly circulation in autumn and winter, and easterly air flow in spring. The zonal circulation had an important role for monthly air temperature both in winter and in summer, whereas meridional air flow in spring and autumn. Compared to the air flow direction, the character of atmospheric circulation, expressed by anticyclonic and cyclonic circulation, had a weak influence on monthly air temperatures. The cyclonicity index most accurately reflects the variability of monthly precipitation totals in the Lublin region

There are many classifications of atmospheric circulation types. In Poland, the most important one, used in climatological studies, is the classification of circulation types developed by Lityński. This study aims to compare the results of two variations of this classification: the “old” one – based on the NCEP/NCAR reanalysis data and on the original limits of the classes (of indicators Ws, Wp and Cp) proposed by the author of the original classification and the “new” one – which also calculates the limits of the classes on the basis of NCEP/NCAR reanalysis material, but with increasingly longer periods each year. In the period 1971–2015 more than 21% of the results of the “new” classification were different from the “old” one. The differences in the frequency of each class (in relation to individual circulation indicators) in the “old” classification were much higher than in the “new” one. Consequently, the use of “new” limits of the classes causes that in the circulation types catalog the division of the distribution of the Ws, Wp and Cp indicators into three classes is more similar to the one of equal-probability. In the second part of the paper, a modification of the “new” classification isproposed. The “new modified” classification, takes into account only the 30 last years while calculating the limits of the classes. Shortening the period based on which the limits of the classes are calculated one can capture long-term variations in the values of individual circulation indicators, and thus the division of their distributions into three classes is even closer to the equal-probability one.

The work is a description of onerousness of bio-thermal conditions occurring at midday during days of tmax≥30°C in three towns located in north-western Poland: Kolobrzeg, Chojnice and Poznan, for people undertaking physical activity of varying intensity. Based on the meteorological data for 12 a.m. UTC from the period 1981–2016 average values of biometeorological (HIS, STI) and thermophysiologial (HR, Oh_H, SW, DhRna) indices, as well as their extreme values and amplitudes were calculated. The frequency of conditions burdening human body, when undertaking exercise outdoors, was also determined. The analyses showed that in the midday hours an increased physical activity leads to an increase in intense thermal sensations and a significant burdening of the human body with heat stress. A potential risk of overheating, that could occur within an hour of intense effort, was noted. A serious risk of dehydration of the body, even at moderate activity, was also indicated. Particularly burdening conditions, with high sultriness and a possibility of hyperthermia were observed in Kolobrzeg.