Rola rzeźby terenu w modyfikacji temperatury powietrza na obszarze miejskim

W okresie 25 marca 2009-27 stycznia 2010 przeprowadzono automatyczne pomiary temperatury powietrza, w 10 punktach w Krakowie, rozmieszczonych w obszarach o różnym użytkowaniu i formie terenu. Teren pozamiejski charakteryzuje "asymetria termiczna" oraz przewaga sytuacji inwersyjnych, na obszarze miejskim dominuje normalne uwarstwienie termiczne i widoczna jest większa rola rzeźby terenu niż jego użytkowania w kształtowaniu rozkładu przestrzennego temperatury powietrza. Struktura termiczna miasta położonego w dolinie powinna być rozpatrywana jako część większej, mezoskalowej struktury termicznej, co najlepiej ilustrują dane z okresów występowania wiatru halnego. Wówczas w części obszarów pozamiejskich jest wyraźnie cieplej niż w centrum miasta, a na samym obszarze miejskim występuje inwersja termiczna, podobnie jak poza miastem. Katabatyczne spływy chłodnego powietrza są prawdopodobnie znacznie silniejsze w północnej części badanego obszaru niż w południowej, co może się wiązać z budową geologiczną i powodować wspomnianą "asymetrię termiczną"

Effect of relief and land use on heat stress in Kraków, Poland

Heat stress in urban areas is controlled mainly by the impact of anthropogenic land use on the active surface heat balance. This paper shows the role of land form superimposed on the land-use impact, using the example of Krakow, Poland. The city is located in a concave land form, on the Wisla (Vistula) River. The automatic measurements of air temperature and humidity were realised in Kraków from April to October, in the years 2010-2012. For the day time conditions, ANOVA test and Tukey’s test showed significant differences in the number of very hot days and number of heat waves, between urban areas in the valley and rural areas, both in the valley and on the slope. For the night time, significant differences were found for the number of tropical nights, not only between urban and rural areas, but also between urban areas located in various landforms and between urban areas in the valley floor and rural areas located in various landforms. Both urban and rural measurement points located in the river valley floor experienced the highest numbers of very hot days, heat waves and extreme air temperature duration. For measurement points elevated about 50 m above the valley floor, the indices’ values were lower by about 50 %

Evolution of studies on local climate of Kraków

Badania nad klimatem lokalnym Krakowa, realizowane po II wojnie światowej, opierały się na obserwacjach i pomiarach stacjonarnych na stacjach meteorologicznych i w punktach pomiarowych działających okresowo, na pomiarach mobilnych, a także na analizie danych sodarowych i satelitarnych. Zróżnicowana rzeźba terenu jest równie ważnym czynnikiem kształtującym klimat lokalny Krakowa jak użytkowanie/pokrycie terenu. Miejską wyspę ciepła należy rozpatrywać jako element struktury termicznej obszaru miasta i okolic w mezoskali, z uwzględnieniem inwersji temperatury powietrza i asymetrii termicznej doliny Wisły w Krakowie i okolicy. Pole opadów atmosferycznych jest znacząco zróżnicowane, głównie wskutek urozmaiconej rzeźby terenu. Sumy roczne opadu są wyższe w mieście niż poza miastem o ok. 80 mm, wyższa jest także liczba dni z opadem, ale dotyczy to tylko dni z sumą dobową poniżej 5 mm. Położenie Krakowa w dolinie Wisły i osłonięcie wypukłymi formami terenu od południa, północy i zachodu powoduje, że naturalna wentylacja pozioma i pionowa jest zła, co przyczynia się do częstego występowania ponadnormatywnych stężeń zanieczyszczeń powietrza. Średnia roczna prędkość wiatru w centrum miasta wynosi 1,8 m·s^{–1}, a częstość cisz atmosferycznych sięga 30%.Studies on local climate of Kraków conducted after the Second World War were based on observations and measu-rements at regular meteorological stations and at short-term measurement points, as well as on mobile measurements and analyses of sodar and satellite data. The diversified landform and the land use/land cover are equally important factors controlling the local climate of Kraków. The urban heat island should be studied as an element of the thermal structure of the city, in the meso-scale, including the impact of air temperature inversions and thermal asymmetry of the Vistula river valley in Kraków. Atmospheric precipitation is highly differentiated spatially due to the impact of relief. The annual totals are higher in the city than in the surrounding areas by about 80 mm; the number of days with precipitation is also greater but the latter is true only for daily totals below 5 mm. The location of Kraków in the Vistula river valley and the sheltering effect of the convex landforms to be found south, north and west of the city are the reason for poor natural horizontal and vertical ventilation, which in turn often generates air pollution concentrations above the acceptable levels. The mean annual wind speed in the city centre is 1.8 m·s^{–1}, and the frequency of atmospheric calm reaches 30%

Impact of wind speed and apartment ventilation on indoor concentrations of PM10 and PM2.5 in Kraków, Poland

In the period 2013-2015, PM_{2.5} and PM_{10} outdoor and indoor concentrations were measured on 23 days in cold half-year periods, in Kraków, Poland. Air pollution is still a serious health hazard for the inhabitants as Kraków is located in a concave landform and smog episodes occur often in the city during the heating periods, due to poor natural ventilation and frequent air temperature inversions. The PM_{10} and PM_{2.5} concentrations were studied for very good and very poor weather conditions concerning air pollution. Each subgroup was further divided into cases when the apartments’ windows were kept open or closed. Daily courses of PM_{10} and PM_{2.5} concentrations were very dynamic.Weather pattern, in particular wind speed and atmospheric stability, largely determined the concentrations of PM_{10} in ambient air. The share of PM_{2.5} in PM_{10} indoor concentrations reached around 70% for both types of weather conditions. The share of indoor PM_{10} and PM_{2.5} mean concentrations in the outdoor values was higher during good than during poor weather conditions by about 10%

Challenges to social capacity building in flood-affected areas of southern Poland

Various aspects of beliefs, behaviour and expectations of at-risk populations were analysed in four case study localities in southern Poland that were affected by flooding in 1997 and 2001. They represent localities of different sizes and are characterised by different paths of historical development. Two of them are deep-rooted communities with dense, strong family and neighbourhood ties, while the other two experienced an almost total replacement of their population due to decisions taken after World War II and still suffer from less developed social networks. Historical events also resulted in the disruption of local memories of flooding and transmission of knowledge about natural hazards. A questionnaire survey was conducted in late autumn 2006, followed by structured telephone interviews and focus group interviews in spring 2008. The results of the survey and interviews were analysed with reference to the social capacity framework and its five dimensions: knowledge, motivational, network, economic and governance capacities. Network capacities, that is resources of bonding and bridging social capital, were considered a key notion when analysing and interpreting the results. The differences in the local resources and abilities available in each of the localities to prepare a response to natural hazards were revealed. Consequently, challenges faced in the process of building and strengthening social capacity were identified as well as ways to address these challenges. It was concluded that there are general trends and tendencies that need to be considered in risk management strategies, however the different starting points of each case study community calls for different means and approaches, as well as producing somewhat different expected outcomes