Learning from the past: Urban climate studies in Munich

Transcription

1 271 Learning from the past: Urban climate studies in Munich Andreas Matzarakis, Helmut Mayer Meteorological Institute, Albert-Ludwigs-University of Freiburg, Germany Abstract A lot research has been conducted in urban climatology in the last four decades. Not only urban heat island has been the point of interest of the investigations and analysis. In the Federal State of Bavaria (southern Germany), several projects have been carried out, e.g. URBAN CLIMATE IN BAVARIA (STADTKLIMA BAYERN), which was mainly focused on the urban climate in the city of Munich. Based on collected and existed data sets, investigations and analysis can be run. Although new techniques, equipments and mapping possibilities exist nowadays, the targets and questions almost remain the same, but can be processed and solved with new technologies and possibilities. 1. Introduction In the first part of the eighties, the extensive urban climate project URBAN CLIMATE IN BAVARIA (STADTKLIMA BAYERN) was performed in three cities in the Fedearl State of Bavaria (southern Germany). Most of the investigations were conducted in the city of Munich, the capital of Bavaria (Baumgartner et al., 1985; Bründl et al., 1986, Mayer, 1986, 1987, 1988). Networks of meteorological stations in the screen and roof level were established in order to determine the urban climate conditions. In addition, car traverses have been established for a detailed analysis of the urban climate conditions in the lower Urban Canopy Layer of Munich. After STADTKLIMA BAYERN several other projects and investigations concerning urban climate structures, urban ventilation and urban air pollutions have been conducted in Munich in order to continue not only scientific research but also to develop and provide material for decision making (Suppan et al., 1989; Mayer and Matzarakis; 1990, Haberfeld, 1992; Matzarakis and Mayer, 1992; Haustein, 1993; Mayer et al., 1994, 1992). Focus was not only on quantifications of single streets, urban street canyons and urban structures but also on the assessment and consideration of urban climate information including air pollution and results in the master plan of cities. Based on the existing data from the research program STADTKLIMA BAYERN and other other urban climate projects conducted in Munich, a comparison of several possibilities and different recent techniques have been made in order to analyse and quantify the data. 2. Methods Methods for analysing urban climate conditions and phenomena exist since several decades. In the last thirty years, because of the new technologies and computer developments, several possibilities have been added as analysing options and tools (Helbig et al., 1999; Mayer, 2000; Matzarakis, 2001; Kuttler and Düttemayer, 2003; Mayer and Matzarakis, 2003; Kuttler, 2004a, b).

2 272 Based on the collected data and the available tools and computer facilities several analyses about urban heat island and urban human-biometeorological conditions have been performed (Mayer, 1988; Matzarakis, 2001; Mayer et al., 2003). Maps of climatological parameters and urban heat island have been produced for planning applications. The results were based on available statistical and interpolation techniques in a time where GIS-techniques were not existed. Based on the first results and in continuous cooperation and exchange with planning and environmental authorities, the demand for information and quantification of urban climate conditions and their effects on citizens moved in the foreground, knowing that thermal images are not the appropriate way for quantification of urban heat island or urban thermal discomfort island (for more detailed information, e.g. effects of urban green, trees and urban air paths see Mayer (2000) as well as Mayer und Matzarakis (2003). Due to the increasing importance of air pollution, one focus has been set on the analysis of urban air pollution (Haustein, 1993; Mayer, 2000). Fig. 1: Thermal image of Munich in the daytime, based on data from project STADTKLIMA BAYERN ( For the urban climate studies in Bavaria in the beginning of the eighties of the 20th century, a standard procedure was meteorological shelters equipped with hygro-thermographs and no automatically collecting possibility for the screen level network. A roof level network consisted of five meteorological stations, thermal imaging (Fig. 1) for the important daily and nocturnal periods, mobile energy balance stations, vertical sound-

3 273 ings and car traverses have been applied and analysed (Bründl et al., 1986; Mayer, 1987, 1988). Fig. 2: Climatic relevant urban structures in Munich based on data from the project STDTKLIMA BAYERN (Bründl et al., 1986)

4 Results Based on urban climate data from Munich measured within the scope of different urban climate projects in the eighties and the beginning of the nineties of the 20 th century, several analyses and applications have been performed (e.g. Bründl et al., 1986; Suppan et al., 1990; Haberfeld, 1992; Haustein, 1993; Matzarakis, 2001; Matzarakis and Mayer, 1992; Mayer und Matzarakis, 1992; Mayer et al., 1994). Suited data from different urban climate methods have been the basis for the construction of urban climatie maps (Figs. 2 and 3). Fig. 3: Synthetic climate function map of Munich, based on data from the research project STADTKLIMA BAYERN (Haberfeld, 1992) With the existing data sets, Matzarakis (2001) has performed human-biometeorological analyses. Based on the old data of the screen level station, Mayer et al. (2003) have investigated the temporal pattern of the moisture in the lower Urban Canopy layer, particularly the urban moisture excess (UME). In addition, further analyses were conducted on the basis of meta data from the urban climate network in screen level, e.g. related to fish-eye photos by Matzarakis and Mayer (2008). They imported the fish-eye photos in the RayMan model (Matzarakis et al., 2008) and calculated the sky view factor. 4. Discussion and conclusions It is common to collect data from experimental and other investigations. Afterwards this data and information were not processed at all due to the lack of time and other limita-

5 275 tions in research projects. In addition in the past, techniques and possibilities operating with extense data files and data sets were not the case. The strong and fast development of analysing possibilities and software products, e.g. GIS, represents an excellent opportunity for new data sets and products. But they can also applied to still existing datasets from past urban climate research projects. Nevertheless, the questions concerning urban climate problems still remain after several decades of urban climate research (Matzarakis, 2005; Kuttler, 2008). The construction and arrangement of urban structures, which lead to optimal urban humanbioclimeteorological conditions for citizens, i.e. an ideal urban climate (Mayer, 1989), is still under discussion. Up to now, the quantification of urban climate processes and resulting phenomena as well as the quantification of contents of urban climate functions maps and resulting recommendation maps for urban planning is not carried out. Therefore, the solution of these problems, which are known since more than 40 years, should be a key objective in applied urban climate research. Acknowledgement The authors would like to express their thanks and honour for all the colleagues (students, technical staff and scientific researchers), who have contributed to the several urban climate projects in Munich. References Baumgartner, A., Mayer, H., Noack, E.-M., 1985: STADTKLIMA BAYERN Final report of the subproject Thermal images of Bavarian cities. Bayer. Staatsministerium für Landesentwicklung und Umweltfragen, Reihe Materialien Nr. 39. (in German) Bründl, W., Mayer, H., Baumgartner, A., 1986: STADTKLIMA BAYERN Final report of the subproject Climate measurements in Munich. Bayer. Staatsministerium für Landesentwicklung und Umweltfragen, Reihe Materialien Nr. 43. (in German) Haberfeld, E., 1992: Synthetic urban climate function map for Munich. Diploma Thesis, Geoscience Faculty, Ludwig-Maximilians-University of Munich. (in German) Haustein, Ch., 1993: Measurements of traffic-related air pollutants in Munich. Wiss. Mitt. Meteorol. Inst. München Nr. 65. (in German) Helbig, A., Baumüller, J., Kerschgens, M., 1999 (eds): Urban climate and air pollution control. Berlin, Springer. (in German) Kuttler, W., 2004a: Urban climate. Part 1: Fundamentals and reasons. UWSF - Zeitschrift für Umweltchemie und Ökotoxikologie 16, (in German) Kuttler, W., 2004b: Urban climate. Part 2: Phenomena and impacts. UWSF - Zeitschrift Umweltchemie und Ökotoxikologie 16, (in German) Kuttler, W., 2008: Country report - Urban climate research in Germany. IAUC Newsletter 29, Kuttler W., Dütemeyer, D., 2003: Investigation methods in environmental meteorology. Promet 30, (in German) Matzarakis, A. 2001: The thermal component of urban climate. Ber. Meteorol. Inst. Univ. Freiburg Nr. 6. (in German)

6 276 Matzarakis, A., 2005: Country report - Urban climate research in Germany. IAUC Newsletter 11, 4-6. Matzarakis, A., Mayer, H., 1992: Mapping of urban air paths for planning in Munich. In: Planning Applications of Urban and Building Climatology. Wiss. Ber. Inst. Meteor. Klimafor. Univ. Karlsruhe Nr. 16, Matzarakis A, Mayer, H., 2008: Dependence of the thermal urban climate on morphological variables. Ber. Meteor. Inst. Univ. Freiburg 17, Matzarakis, A., Rutz, F., Mayer, H., 2007: Modelling radiation fluxes in simple and complex environments - Application of the RayMan model. Int. J. Biometeorol. 51, Mayer, H., 1986: Objective and structure of the research project STADTKLIMA BAYERN. Mitt. Geogr. Gesell. München 71, (in German) Mayer, H., 1987: Results from the research project STADTKLIMA BAYERN. Mitt. Geogr. Gesell. München 72, (in German) Mayer, H., 1988: Results from the research program STADTKLIMA BAYERN for urban planning. Energy and Buildings 11, Mayer, H., 1989: Workshop Ideal Urban Climate on 26 October 1988 in Munich. DMG-Mitt. 3/89, (in German) Mayer, H., 2000: Umweltmeteorology at the outset of a new century. Gefahrstoffe Reinhaltung der Luft 60, (in German) Mayer, H., Matzarakis, A., 1990: Urban climate relevant air paths in Munich (STADTLUFT). Report for the period to Chair for Bioclimatology and Applied Meteorology, Ludwig-Maximilians-University of Munich. (in German) Mayer, H., Matzarakis, A., 1992: Urban climate relevant air paths in Munich (STADTLUFT). Final Report. Chair for Bioclimatology and Applied Meteorology, Ludwig-Maximilians- University of Munich. (in German) Mayer, H., Matzarakis, A., 2003: Future outlooks in the environmental meteorology. Promet 30, (in German) Mayer, H., Beckröge, W., Matzarakis, A., 1994: Determination of urban climate relevant air paths. UVP-Report 5/94, (in German) Mayer, H., Matzarakis, A., Iziomon, M.G., 2003: Spatio-temperal variability of moisture conditions within the Urban Canopy Layer. Theor. Appl. Climatol. 76, Suppan, P., Matzarakis, A., Mayer, H., Höppe, P., 1989: Research project KLIWUS (Investigation on the microscale impact of urban structures). Research project on behalf of the Environmental Department, City of Munich. (in German) Authors' address: Prof. Dr. Andreas Matzarakis (andreas.matzarakis@meteo.uni-freiburg.de) Prof. Dr. Helmut Mayer (helmut.mayer@meteo.uni-freiburg.de) Meteorological Institute, Albert-Ludwigs-University of Freiburg Werthmannstr. 10, D Freiburg, Germany