UDC4: Impact of Urban forms on comfort III : theoretical studies
Effects of Different Floor Covering Materials on Thermal Comfort in Landscape Design Studies
1Ataturk University, Turkey; 2Ataturk University, Turkey
In the context of this study, effects of six different floor covering materials (grass, travertine, empenyel wood, andesite, soil and asphalt) on thermal comfort are determined. Three different landscape design projects covering 500square meters with different floor materials are analysed for thermal comfort. During July in cloudless days, PET (Physiologicall Equivalent Temperature) values were measured by using RayMan Pro2 program with surface temperatures, air temperature, wind and humidity data obtained at 12:00. The findings show that according to PET values (grass: 25.9İC, travertine: 26.1İC, empenyel wood: 28.9İC, andesite: 27.1İC, soil: 27.5İC and asphalt: 28.5İC); PET value was calculated as 26.3İC in the first project in which surfaces mostly covered with grass and travertine; in the second project mostly covered with wood and asphalt, PET value was 28.1İC; and finally in the third project, PET was calculated as 27.02İC. In conclusion, design based suggestions related to the use of floor materials in urban areas are made for decreasing urban heat island effects and for designing comfortable places in hot climate cities.
Keywords: Landscape design comfort, PET, landscape surfaces, temperature control
Impact of Urban Morphology on Average Urban Albedo
the University of Hong Kong, Hong Kong S.A.R. (China)
A three-dimensional Model for Urban Surface Temperature (MUST), which consists of a rigorous radiation scheme on the urban surface for a complex city, is used to investigate the impact of canyon geometry on average urban albedo. The model performs well in terms of predicting urban albedo. Urban albedo is defined as the ratio of incoming to outgoing shortwave radiation at the upper edge of the urban canopy layer, the value of which may vary throughout the time. Thus, we introduce an average urban albedo of a day to eliminate the time effect. Three scenarios are tested in the research, in order to study the impact of canyon density, building height and building height uniformity on the average urban albedo. The estimated results of the urban average albedo for different canyon geometry shows that the medium-density urban absorbs the solar radiation most and the average urban albedo is found to decrease with increasing building height. Also, more solar radiation will be absorbed as the geometry getting disordered. Overall, the average urban albedo is less for a moderately compact city having high-rise buildings with varying building heights than other cases.
Analysis of human thermal conditions in winter for different urban structures in Erzurum
1Ataturk University, Turkey; 2Ataturk University, Turkey; 3Anadolu Univ., Research Institute of Earth and Space Sciences; 4Ataturk University, Turkey; 5Albert-Ludwigs University of Freiburg/Germany
Analysis of human thermal conditions in winter for different urban
structures in Erzurum
Healthy urban planning and urban modelling is necessary for sustainable urbanization. For this purposes, this study was carried out in the city of Erzurum located 2000m altitude. It is the coldest city in Turkey started urban transformation projects in the last few years. Four different parts of the urban areas are decided for the case study as Erzurum city center (1), Botanic garden of Ataturk University (2), Yenisehir (3) and Dadaskent (4). PET and SVF were measured in these areas and measurements were made at 9:00, 12:00, 15:00 and 18:00 because they are peak hours in which people are using outside places in winter months (December- January - February). Life comfort, which is the issue tried to be measured in this study, is extremely important for long winter period cities. In addition to PET and SVF, Landsat satellite images are used for the measurement and in this process; different categories are defined for determination of alteration in the heat islands. In conclusion, related to the structural and plant design in urban areas, design based suggestions are made for increasing urban comfort.
Keywords: Urban design, PET, Winter comfort, SVF, Thermal Band, trees