Research Center Human Biometeorology

Freiburg, Germany

Research Center Human Biometeorology

Freiburg, Germany
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Lin T.-P.,National Cheng Kung University | Chen Y.-C.,National Cheng Kung University | Matzarakis A.,Research Center Human Biometeorology
Sustainable Cities and Society | Year: 2017

Urban thermal stress climatic maps present the features of urban thermal conditions relevant for planning by integrating climate parameters and urban development information. Planners can easily identify thermal environment characteristics and detect existing problems in urban climatic information to make appropriate decisions regarding urban planning processes. In this study, the metropolitan area of Taichung City was chosen as a study area to analyze urban development factors. First, the gridding approach was used to generate a standardized process for constructing a thermal stress map of the study area. Second, basic layers, including population density, land-use zoning, building total floor area, and land cover type, were collected. Third, development layers, including the sky view factor and impervious surface ratio, were established. Fourth, mobile and fixed-point meteorological measurements were obtained twice a month in 2013–2014. The measurement results and layer information were integrated to establish the thermal stress estimation equation through multiple regression analysis. Finally, the long-term climate data of Taichung City were imported into the estimation equation to determine the thermal stress risk and thermal stress potential through the application of a physiologically equivalent temperature. The thermal stress map can demonstrate the link between urban development and human thermal perception, thereby enhancing climate adjustment for urban areas. © 2017 Elsevier Ltd

Rodriguez-Algeciras J.,University of Camagüey | Tablada A.,National University of Singapore | Matzarakis A.,Research Center Human Biometeorology
Theoretical and Applied Climatology | Year: 2017

Walkability and livability in cities can be enhanced by creating comfortable environments in the streets. The profile of an urban street canyon has a substantial impact on outdoor thermal conditions at pedestrian level. This paper deals with the effect of asymmetrical street canyon profiles, common in the historical centre of Camagüey, Cuba, on outdoor thermal comfort. Temporal-spatial analyses are conducted using the Heliodon2 and the RayMan model, which enable the generation of accurate predictions about solar radiation and thermal conditions of urban spaces, respectively. On these models, urban settings are represented by asymmetrical street canyons with five different height-to-width ratios and four street axis orientations (N-S, NE-SW, E-W, SE-NW). Results are evaluated for daytime hours across the street canyon, by means of the physiologically equivalent temperature (PET index) which allows the evaluation of the bioclimatic conditions of outdoor environments. Our findings revealed that high profiles (façades) located on the east-facing side of N-S streets, on the southeast-facing side of NE-SW streets, on the south-facing side of E-W street, and on the southwest-facing side of SE-NW streets, are recommended to reduce the total number of hours under thermal stress. E-W street canyons are the most thermally stressed ones, with extreme PET values around 36 °C. Deviating from this orientation ameliorates the heat stress with reductions of up to 4 h in summer. For all analysed E-W orientations, only about one fifth of the street can be comfortable, especially for high aspect ratios (H/W > 3). Optimal subzones in the street are next to the north side of the E-W street, northwest side of the NE-SW street, and southwest side of the SE-NW street. Besides, when the highest profile is located on the east side of N-S streets, then the subzone next to the east-facing façade is recommendable for pedestrians. The proposed urban guidelines enable urban planners to create and renovate urban spaces which are more efficient in diminishing pedestrian thermal stress. © 2017 Springer-Verlag GmbH Austria

Rodriguez Algeciras J.A.,University of Camagüey | Matzarakis A.,Research Center Human Biometeorology
International Journal of Biometeorology | Year: 2015

In order to contribute to the sustainability of the outdoor environment, knowledge about the urban thermal bioclimate should be transferred into climatic guidelines for planning. The general framework of this study responds to the need of analyzing thermal bioclimate in Mediterranean climate regions and its influence as an urban design factor. The paper analyzes the background of the urban climate and thermal bioclimate conditions in Barcelona (Spain), through the effect of shade conditions and wind speed variations. Simulations of shade and wind speed variations were performed to evaluate changes in thermal bioclimate due to modifications in urban morphology. Air temperature, relative humidity, wind speed, and solar radiation for the period from January, 2001 to January, 2015 were used to calculate physiologically equivalent temperature (PET) using the RayMan model. The results demonstrate that shade is the most important strategy to improve urban microclimatic conditions. In Barcelona, human thermal comfort conditions can be improved by shade and wind speed increase in terms of PET above 23 °C and by a wind speed decrease for thresholds of PET below 18 °C. Heat stress situations can be mitigated by shade and wind speed increase in conditions above 35 and 45 °C, respectively. The results of the study are an important contribution for urban planners, due to their possibilities and potential for the description of microclimatic conditions in Mediterranean climate regions. The knowledge is useful for improved human thermal comfort conditions, from the suitable configuration of urban form and architecture. © 2015 ISB

Rodriguez Algeciras J.A.,University of Camagüey | Gomez Consuegra L.,University of Camagüey | Matzarakis A.,Albert Ludwigs University of Freiburg | Matzarakis A.,Research Center Human Biometeorology
Building and Environment | Year: 2016

The conservation of historical urban centres is an important resource to encourage liveability and sustainable development of cities in the context of global climate change. It is a complex process that serves diverse perspectives, among them is the thermal comfort. The paper analyze the contribution of street configuration towards the improvement of thermal comfort at pedestrian level, in the Old Town of Camagüey-Cuba (World Heritage Site, since 2008). Simulations performed are run for summer and winter solstices by using RayMan model. The urban settings are represented by symmetrical street canyons (380 m long, 9 m width), with different solar orientations (i.e. N-S, NE-SW, E-W, NW-SE) and aspect ratios (i.e. H/W = 0.5, 1, 1.5, 2, 3, 4, 5). Results are presented in terms of Physiologically Equivalent Temperature (PET). Our findings confirm that the spatial distribution of thermal conditions at street level, depend strongly on aspect ratio and street orientation. The results show extreme patterns of thermal comfort between N-S and E-W streets. Rotation to N-S orientation is a valid strategy to mitigate the heat stress in summer, with reductions of up to 2 h at the center of the street. Aspect ratios between 1 and 1.5 offer a quite acceptable thermal performance for summer and winter. PET patterns discussed give information about the most suitable locations for pedestrian within the street. The urban guidelines presented enable to urban planners rehabilitate and design cities, which are able to reduce the impact of thermal stress in hot-humid climates. The results could be included in the Urban Regulations of Camagüey. © 2016 Elsevier Ltd.

Gueguen F.,CNRS Hydrology and Geochemistry Laboratory of Strasbourg | Stille P.,CNRS Hydrology and Geochemistry Laboratory of Strasbourg | Dietze V.,Research Center Human Biometeorology | Giere R.,Albert Ludwigs University of Freiburg
Atmospheric Environment | Year: 2012

Passive air samplers have been installed in industrial, urban, rural and remote forested environments in order to collect coarse airborne particles for subsequent chemical characterization. To identify principal polluting sources, isotopic tracers, such as Sr, Nd and Pb isotopic ratios, have been used. The mass deposition rates (MDRs) of trace metals, determined for each of the studied environments, clearly indicate that industrial and traffic sites are especially affected by air pollution. Elements such as V, Pb, Fe, Cr, Co, Mo, Cd, Ni, As, Sb and Zn are notably enriched in samples from industrial zones, whereas V, Mn, Ba, Sr, Al, U, Th, rare earth elements (REE), Zr, Y, Cs, Rb, Sb, Sn and Cu are principal components of the airborne particles collected close to areas influenced by heavy traffic. The chemical/isotopic baseline composition derived from the airborne particles is the result of mixing of particles from different industrial sources, traffic and fertilizers. The monthly analysis of trace-metal MDRs of the collected airborne particle samples from different stations around the industrial zone allows for the detection of distinct atmospheric dust-deposition events during the year, characterized by high MDRs. " Natural" dusts from regional soil re-suspension, including from more distant regions like the Sahara desert, might overprint the regional atmospheric baseline composition, as suggested by trace metal trajectories in ternary diagrams and by Sr, Nd and Pb isotope data. © 2012 Elsevier Ltd.

Ketterer C.,Albert Ludwigs University of Freiburg | Matzarakis A.,Albert Ludwigs University of Freiburg | Matzarakis A.,Research Center Human Biometeorology
Landscape and Urban Planning | Year: 2016

The gap between point measurements made during a measurement campaign and the required discrete data of human thermal comfort in the form of maps could be overcome by statistical or numerical models. City planners usually demand thermal maps with a resolution below 50 m. The required input data for the statistical models were meteorological data at high resolution as well as land use and land cover data including morphological data. Meteorological data were obtained through car traverses on a measuring campaign on hot summer days in July 2014. The chosen statistical approaches of stepwise multiple linear regression and artificial neural network were compared for the case study area Stuttgart, Germany. The Physiologically Equivalent Temperature (PET) was applied to analyse the human thermal conditions taking into account both the meteorological environment and the thermo-physiological parameters including the human energy balance. The polycentric and complex spatial distribution of heat stress and heat load is clearly visible in the created maps. One hot spot is the city centre and its surrounding residential neighbourhood, the other hot spot can be detected in Bad Cannstatt (easterly of the Neckar river valley), including industrial and residential areas. Thereby, the non-linear artificial neural network model delivers better results than the stepwise multiple linear regression model. Advantages of the artificial neural network arise from the possibility to reveal non-linear dependencies and interactions between the variables resulting in a better model fit. © 2016 Elsevier B.V.

Schleicher N.,Karlsruhe Institute of Technology | Kramar U.,Karlsruhe Institute of Technology | Dietze V.,Research Center Human Biometeorology | Kaminski U.,Research Center Human Biometeorology | Norra S.,Karlsruhe Institute of Technology
Atmospheric Environment | Year: 2012

Volcanic particles can be transported over long distances in the atmosphere and can cause severe problems for air traffic. This was the case over large areas of Europe in spring 2010 after the eruption of the Eyjafjallajökull (E15) volcano on Iceland.The scope of this work was to characterize these volcanic particles more in detail with regard to size and chemical composition in order to provide valuable information needed for a better estimation of the possible impact on airplane jet engines and cockpit windows. Another question of this study was which share of the overall atmospheric particles in Germany originated from the E15 eruption and whether this amount of volcanic particles could cause any adverse health effects to humans. To this end, single particle analysis by means of scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and synchrotron radiation based micro X-ray fluorescence analysis (μS-XRF) together with multivariate statistical methods were applied for samples collected on ground-level in Southwest Germany and Iceland. Based on the obtained chemical fingerprints combined with multivariate statistical methods it was possible to discrimate between the amount of volcanic particles from Iceland and other atmospheric particles from non-volcanic sources. This aspect distinguishes this single particle approach from most other studies. The results of the study showed that at least 40% of the analyzed particles between 2.5 and 10μm size at the remote sampling sites in the Black Forest area and about 25% in the city of Freiburg were clearly of volcanic origin from the E15 volcano eruption event. © 2011 Elsevier Ltd.

Schleicher N.,Karlsruhe Institute of Technology | Norra S.,Karlsruhe Institute of Technology | Fricker M.,Research Center Human Biometeorology | Kaminski U.,Research Center Human Biometeorology | And 5 more authors.
Environmental Pollution | Year: 2013

The spatial and temporal distribution and the flux of black carbon (BC) concentration in Beijing were continuously investigated over a two-year period at five sites to highlight the relative influence of contributing sources. The results demonstrate firstly that there is significant spatio-temporal variability of BC in Beijing. Highest concentrations occurred during winter primarily due to stagnant meteorological conditions, and seasonal BC sources, such as coal combustion for heating purposes. Biomass burning was identified as a minor seasonal source during the summer months. BC also varied spatially with higher concentrations in the SE of Beijing and lower concentrations in the NW, due to the differing emission intensity of various local BC sources such as traffic and industry. Frequently, overnight BC concentrations were higher due to specific meteorological conditions, such as the lower urban mixing layer height and various anthropogenic activities, such as exclusive night-time heavy duty vehicle traffic in the inner-city. © 2013 Elsevier Ltd. All rights reserved.

Yang S.-Q.,Albert Ludwigs University of Freiburg | Matzarakis A.,Research Center Human Biometeorology
International Journal of Biometeorology | Year: 2016

Köppen-Geiger climate classification (KGC) is accepted and applied worldwide. The climatic parameters utilised in KGC, however, cannot indicate human thermal comfort (HTC) conditions or air humidity (AH) conditions directly, because they are originally based on climatic effects on vegetation, instead of that on human body directly. In addition, HTC is driven by meteorological parameters together. Thus, the objective of this study is to preliminarily implement the HTC information and the AH information in KGC. Physiologically equivalent temperature (PET) has been chosen as the HTC index, and vapour pressure (VP) is for the quantification of AH conditions. In this preliminary study, 12 Chinese cities in total have been taken into account as the assumed representatives of 11 climate types. Basic meteorological data of each city with 3-h resolution in 2000–2012 has been analysed. RayMan model has been applied to calculate PET within the same time period. Each climate type has been described by frequencies of PET and frequencies of VP. For example, the Aw (Sanya) has the most frequent occurrence of thermally stressful conditions compared to other climate types: PET in 22 % points in time of the year was above 35 °C. The driest AH conditions existed in Dwc (Lhasa) and Dfb (Urumqi) with VP rarely above 18 hPa in the wettest month. Implementation of the HTC information and the additional AH information in each climate type of KGC can be helpful for the topics of human health, energy consumption, tourism, as well as urban planning. © 2016 ISB

Sharmin T.,University of Cambridge | Steemers K.,University of Cambridge | Matzarakis A.,Research Center Human Biometeorology
Building and Environment | Year: 2015

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-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. © 2015 Elsevier Ltd.

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