Impact of the COVID-19 pandemic on competitive swimming performance

OBJECTIVE This article aims to conduct a comparison of swimming performance during short course national championships (25-m) from 2019 and 2020 (before and during the pandemic). MATERIALS AND METHODS The data points from the championships will be compared for 5 European countries: Poland, Spain, Russia, Turkey, and Denmark. Times achieved in the finals were calculated by the analysis of variance. Post hoc pairwise comparison analysis was performed using Tukey's test. The analysis plan included the assessment of the main effects and the effect of interactions in the groups of women and men. The strength of the effect was expressed by the partial eta-squared ratio. RESULTS Two main trends were observed in the results. The first was a greater variation in the results in the group of men than in women (12-5 differences). The second was the development and improvement of sports performance in symmetrical strokes (69% improvement in recorded times measured during the pandemic, e.g., in Poland, women on 50-m breaststroke and butterfly Δ = 0.52, p <0.001 and Δ = 0.32, p = 0.034, men on 50-m and 100-m butterfly Δ = 0.34, p = 0.003 and Δ = 1.21, p <0.001). CONCLUSIONS The main conclusion of our analysis is that the pandemic influenced the development of sports performance in symmetrical techniques, i.e., in breaststroke and butterfly

Types of gullies and conditions of their development in silvicultural loess catchment (Szczebrzeszyn Roztocze region, SE Poland)

The aim of this paper is to present a characteristic of loess permanent gullies, which form the branched erosion system, with the total length of almost 7.8 km, dissecting an erosion-denudation dry valley. Only 20%of the gully system catchment is cultivated as the result of steep slopes and considerable height differences up to 100 m. 80%of the catchment is covered by fir coniferous forest and Carpathian beech forest, and gully development is the result of intensive forest exploitation. Five types of gullies have been selected on the basis of the runoff directions, which are determined by the following: original relief, runoff concentration from fields, runoff concentration from fallplaces, skidding and course of forest roads used to carry a timber

Phases of aeolian accumulation on the Vistula Spit (Southern Baltic Sea) in the light of TL dating and analysis of a digital elevation model

The genesis of the Vistula Spit (Southern Baltic Sea) in the Postlitorina period is regarded as occurring by gradual addition of successive dune ridges along the entire length of the form. Based on the degree of soil profile development and radiocarbon dating of organic sediments three main stages of aeolian processes are usually recognized. GIS analysis of a digital elevation model (DEM) and thermoluminescence dating of dune sand supports the model of progressive development of dune ridges, and has identified four periods of intense aeolian activity. These were established 5860–5400, 1930–1610, 1200–900 years ago from the present, and from 500 years ago