No abstract

Heat stress is one of the most critical factors affecting human life. In Central Europe, its influence is noticeable, especially in the Polish–Saxon region, which is a very popular tourist region also inhabited by a high number of elders. The main goal of this paper was to assess multi-annual changes in heat stress occurring in the region, considering the frequency of heat days, the UTCI (Universal Thermal Climate Index), and circulation conditions. The research showed that all the thermal and biothermal indices in this region significantly increased during 1971–2019 in the lowlands, the mountain foreland, and the lower mountain zone. In terms of the UTCI, a negative trend for cold stress frequency was noticed in the entire region in favor of an increase in a tendency toward thermoneutral conditions and heat stress. This concerns especially strong and very strong heat stress (UTCI > 32 °C), in which positive trends were observed for most of the stations located in the lower hypsometric zones. The results also showed that heat stress mainly occurs on days with anticyclonic circulation. Analysis of selected cases of heat waves in the 21st century indicated that the lower hypsometric zones are characterized by a very high UTCI, while the summit zone is free from heat stress occurrence.

Abstract. current and future climate conditions and their impact on water balance, ecosystems, air quality and bioand agro-climatology were investigated in the region of the lusatian neisse within the two eu-projects -neyMO and klaPS. This work focuses on the climate analysis of the region at the german-Polish border as a preliminary step for a hydrological analysis of current and future conditions.Observed climatological data were processed and analysed using the indicators air temperature, precipitation, sunshine duration, potential evapotranspiration and the climatic water balance (cWB). the latter defines the difference between precipitation and potential evapotranspiration and is a measure for the climatological water availability in the region. Observations were used to statistically downscale data from global circulation Models under various scenarios regarding greenhouse gas emissions (a1B, rcP 2.6, rcP 8.5) and applying the weTTreg-method for regionalization. in total, 50 climate projections for periods up until the end of the 21 st century were analysed, with the application of the mentioned indicators.For the period 1971-2010, increasing trends of temperature, precipitation, sunshine duration and potential evapotranspiration were found. This leads to a reduced cwB in the summer half-year (Shy), which could be partly compensated by an increase in the winter half-year (why). Trends of temperature, sunshine duration and potential evapotranspiration remain positive for the far future (2071-2100), but precipitation decreases. These climatic conditions aggravate water availability, especially in the Shy. impacts on water management are very probable and were therefore further investigated in the neyMO project that applied hydrological models.

The main goal of this paper was to assess the intensity of heat stress in Lower Silesia, Poland, during selected weather events characterized by high air temperatures. The complex impact of weather on the thermal load of the human organism is presented using the Universal Thermal Climate Index (UTCI). The analysis was carried out for the 2015 and 2018 summer seasons and compared with the multiannual period of 1971–2018. It was based on meteorological data from the IMGW-PIB stations of Wrocław, Jelenia Góra and Śnieżka. In order to examine how heat conditions affect UTCI in different geographical regions, stations located at different altitudes and representing the lowlands, the lower mountain zone and the summit zone of the Sudetes Mountains were considered. The research showed that during the most extreme thermal events, UTCI values in the lowlands and the lower mountain zones can be among the highest heat stress classes. In the summit zone, the maximum UTCI values are usually classed as ‘no thermal stress’.

Water resources are one of the most important issues affected by climate change. Climate scenarios show that in the upcoming decades, further climate change can occur. It concerns especially air temperature and sunshine duration, whose prognosis indicates a significant rising trend till the end of the century. The goal of the paper was the evaluation of water resources and hydropower production in the future, depending on climate scenarios with a consideration of risk analysis. The analysis was carried out on the basis of observation data for the Lusatian Neisse river basin (Poland) for 1971–2015 and climate projections till 2100 for the RCP2.6 and RCP8.5 (representative concentration pathways) scenarios. The results of the research showed that, especially in terms of RCP8.5, very high risk of decrease in water resources and hydropower production is expected in the future. Therefore, recommendations for mitigation of the possible effects are presented.