Pilot actions in European cities - Stuttgart

The field of urban climatology has a long tradition in Stuttgart. It exists as discipline in Stuttgart since 1938. Stuttgart was the first city to establish its own Department of Climatology to research ways of improving the flow of fresh air into the city and to reduce thermal stress in most populated city districts. The specialist department of Urban Climatology, within the Environmental Protection Office, deals with tasks relating to environmental meteorology within the scope of air pollution control and also relating to urban and global climate protection. So in Stuttgart the urban heat island phenomenon (UHI) is studied for several decades, leading to a high level understanding of the UHI and the problems which it causes. The UHI causes an increase in air temperatures and thermal stress, that are identified as most negative impacts on human health and urban living. In the view of global climate change and the predicted temperature rise for the Stuttgart region of 1.5–2 K in this century, the negative impacts of UHI on human health and urban living will become more problematic in the future. According to the results of climate models the frequency of very hot days is expected to jump by nearly 30 % at the end of the century. The rising temperatures due to the global climate change in combination with the temperature shift as a result of the UHI will intensify the heat stress in urban areas, that leads to a significant increasing risk to human health, in particular to the very young and elderly. Not least due its importance for the human health and the quality of urban life in Stuttgart, the UHI is focussed by urban planners and is noticed by the future development of the city. Within the pilot action study in Stuttgart several measure for reducing the UHI and the impacts on urban living and human health are analysed by the use of micro-scale and macro-scale simulations. With the help of these analysis realisable measure are selected. The most useful measures are implemented into a developmoutline plan for the redevelopment of the city district Stuttgart-West by the municipal urban planners

Thermal bioclimate analysis for Europe and Italy

Thermal bioclimate indexes (as thermal comfort or heat stress indexes) are one of the main issues concerning tourism and health conditions especially for expected climate change. The Mediterranean area and countries such as Italy, Spain, France, Turkey and Greece, whose economies are markedly dependent on tourism, are vulnerable regions concerning climate change. In the present study thermal comfort and heat stress (here with the thermal index physiologically equivalent temperature—PET) are analysed in order to quantify the monthly conditions in this area. Additionally, based on climate change scenarios, the seasonal pattern of PET for the period 2070-2100 has been calculated. The results show that the expected conditions of thermal comfort especially for the Mediterranean and Italy will be higher, during summer, about two to three classes of thermal stress for the “business as usual” climate scenarios, and one class of thermal stress for winter. Adaptation and mitigation strategies are hence required for the protection of human health and tourism state and potentialities

THERMAL COMFORT TRENDS AND VARIABILITY IN THE CROATIAN AND SLOVENIAN MOUNTAINS

Mountain meteorological stations played an extremely important role in weather forecasting in the past because they were the only available data source on meteorological conditions several hundred metres above the sea level. Nowadays they are mainly used to estimate the climatic variations and the climate change trends in the environment that is not under the direct influence of the local anthropogenic factors. Two mountain meteorological observatories were chosen to illustrate climatic and bioclimatic trends and variability, Zavižan in Croatian Dinaric Alps and Kredarica in Slovenian Julian Alps. Both have the same monitoring protocol and similar instruments. Because of their unchanged surrounding since time of establishment the data from both observatories are extremely valuable for studying changes in sensitive mountain ecosystems in both countries. Data from the period 1955-2004 were used to assess mountain climatic and bioclimatic variability and trends in Croatia and Slovenia. Results point at the significant increase in the thermal bioclimate index (PET) based on the human energy balance models. At both sites the increase is mainly caused by temperature changes

Differences in the thermal bioclimatic conditions on the urban and rural areas in a southern Hungarian city (Szeged)

The aim of this study is to compare the bioclimatic situation of a city and the surrounding rural area on the example of a Southern Hungarian city (Szeged). To examine the frequency of the one hour averages of the PET index, it is shown that due to the strong direct radiation a strong or extreme heat stress values has 1.1 % higher occurrence in the rural areas compared to the urban ones. But considering the PET averages through the whole examined time period, it is 14 % higher in the urban areas. This effect is more pronounced in summer, when daytime with extreme heat stress is followed by night with 7-8 °C higher PET values in the city. During these times, the human body cannot regenerate in the nights before the repeated extreme heat stress occurs again during daytime. This makes the urban bioclimatic conditions (in summer, especially during heat wave) more demanding, compared to the rural ones

THERMAL BIOCLIMATE CONDITIONS IN THE ALPINE REGIONS OF AUSTRIA

Data of 46 climate stations located from 1000 m to 3105 m a.s.l. were used to describe the thermal human bioclimate conditions in the alpine regions of Austria. Austria possesses a dense network of climate stations with daily measurements and observations of air temperature, relative humidity, wind velocity and mean cloud cover at 7, 14 and 19 LMT . To show the special climate conditions in alpine regions the behaviour of this parameters in relationship to the human energy balance is used to give a description of the effect of the thermal environment on humans. The importance of topography leading to inversions during the cold seasons and clothing resistance to modify the individual thermal bioclimate will be shown exemplarily

Analysis of microclimatic diversity and outdoor thermal comfort perceptions in the tropical megacity Dhaka, Bangladesh

The study has observed microclimatic conditions in residential, commercial and educational areas in Dhaka city. Comfort surveys were carried out along with microclimatic measurements. Findings suggest, urban forms that are more variable with irregular plot sizes and building heights, mostly in traditional areas, have positive responses with respect to the synoptic climate, while planned areas with uniform plot sizes and height, shows a tendency to develop daytime urban heat island effect. An east-west orientated street in a formal residential area was found to be 1°C to 3.8°C warmer than a street in a traditional residential area in the same orientation. It is apparent that the differences are directly linked to the specific geometric pattern of the areas and can be defined by the parameters like uniformity versus diversity and compactness versus openness. Uniform heights, equal building separation and plot sizes can lead to harsher urban microclimate, while variety in these may foster positive changes. Lack of such variety can even affect compact urban areas. This is also evident from the analysis of pedestrian’s responses in the case-study areas. Pedestrians in the formal planned areas or less diverse traditional areas were found to be less comfortable than those in the more variable areas. A statistical analysis of climatic variables and thermal sensation showed moderately strong and significant correlations. These reveal that urban geometry and the resultant climatic variables may not be the only, but one of the most important factors for governing the outdoor thermal comfort sensation in a tropical climate.This paper is drawn from research funded by the Schlumberger Foundation at the University of Cambridge, Department of Architecture.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.buildenv.2015.10.00

Human-Biometeorological Assessment of Urban Structures in Extreme Climate Conditions: The Example of Birobidzhan, Russian Far East

The study shows the effect of urban structures on human thermal comfort indices in the extreme climate region of the Russian Far East, with an annual temperature range of 75 ∘ C. The study examines different urban zones in Birobidzhan, the capital city of the Jewish Autonomous Region (JAR). The climate of this region can be characterized as continental monsoon climate. The difference of thermal values for three zones with different vegetation and build-up density shows the influence of urban planning on the local microclimate. The moderating effect of dense build-up and inner city vegetation on extreme thermal conditions becomes clear when comparing all zones. Through the analysis of daily and monthly timelines it was possible to determine preferable times of the day for inner city outdoor activities. From the results derived from PET with a total of 170 days per year with PET values below 0 ∘ C Birobidzhan can be considered a region of extreme cold stress. This means that an adaptation based solely on behaviour and clothing is not sufficient, but an adaptation of the urban surroundings and therefore the identification and choice of preferable urban structures is necessary

THERMAL HUMAN BIOCLIMATIC CONDITIONS FOR AUSTRIA AND THE ALPS

Abstract. Daily measurements and observations at numerous times of air temperature, relative humidity, wind velocity and mean cloud cover arc the required data for the calculation of the Physiological Equivalent Temperature PET. PET represents a thermal index, which is based on the human energy balance of the human body, for the description of the effect of the thermal environment on humans. We analysed the thermal human bioclimate in Austria using the data from the dense climate network with daily measurements and observations at 7, 14 and 19 LST of 201 stations covering the period 1991 to 2000 as input to compute PET. The results were compared with the outcome of the computation using the synoptic data not only from Austria but also from the surrounding countries and the Alps region. The obtained results give fundamental information often demanded by the tourism and recreation authorities

Comparisons of urban and rural heat stress conditions in a hot–humid tropical city

Background: In recent years the developing world, much of which is located in the tropical countries, has seen dramatic growth of its urban population associated with serious degradation of environmental quality. Climate change is producing major impacts including increasing temperatures in these countries that are considered to be most vulnerable to the impact of climate change due to inadequate public health infrastructure and low income status. However, relevant information and data for informed decision making on human health and comfort are lacking in these countries. Objective: The aim of this paper is to study and compare heat stress conditions in an urban (city centre) and rural (airport) environments in Akure, a medium-sized tropical city in south-western Nigeria during the dry harmattan season (January–March) of 2009. Materials and methods: We analysed heat stress conditions in terms of the mean hourly values of the thermohygrometric index (THI), defined by simultaneous in situ air temperature and relative humidity measurements at both sites. Results: The urban heat island (UHI) exists in Akure as the city centre is warmer than the rural airport throughout the day. However, the maximum UHI intensity occurs at night between 1900 and 2200 hours local time. Hot conditions were predominant at both sites, comfortable conditions were only experienced in the morning and evenings of January at both sites, but the rural area has more pleasant morning and evenings and less of very hot and torrid conditions. January has the lowest frequency of hot and torrid conditions at both sites, while March and February has the highest at the city centre and the airport, respectively. The higher frequencies of high temperatures in the city centre suggest a significant heat stress and health risk in this hot humid environment of Akure. Conclusions: More research is needed to achieve better understanding of the seasonal variation of indoor and outdoor heat stress and factors interacting with it in order to improve the health, safety, and productivity of Akure city dwellers

the urban corridor of venice and the case of padua

Urban Heat Island effect was widely studied in large cities around the world, more rarely in medium size ones. The chapter reports on the study of the UHI phenomenon in Padua, a medium size city of the North-East of Italy, one of the most industrialized and developed parts of the country. Experimental measurements were carried out during 2012 summer, recording the main thermo-hygrometric variables (dry-bulb temperature, relative humidity, global solar radiation) by a mobile survey along an exact path crossing different zones of the city area: urban, sub-urban and rural. The analysis of the data highlights the presence of UHI effect with different magnitudes in function of the zone of the city. In the city centre, an historical zone, the effect was up to 7 °C. In the meantime, some measurements in situ were carried out in order to evaluate other thermal comfort indexes rather than air temperature and humidity only: wind velocity and mean radiant temperature (besides the other meteorological variables) in some characteristic sites of the city area like historic centre, high and low density populated residential zones, industrial zone, rural zone, were recorded. In particular, a very famous square of the city (Prato della Valle) was analysed: it can be considered representative of the phenomenon because of the size and the very different characteristics from the UHI effect point of view. RayMan simulation model was used to calculate some outdoor comfort indexes and Envimet model was further used to evaluate the effect of some mitigation strategies in characteristic sites of the city