Climatic and thermal comfort analysis of the Tel-Aviv Geddes Plan: A historical perspective

This paper examines how the first urban plan of Tel-Aviv (the Geddes Plan of 1925) [18] affected outdoor human thermal comfort in two periods: at the time of its implementation (1920-1930s) and in the present day (2010s). Additionally, this paper questions which of the two - shade or wind velocity - has greater influence on outdoor thermal sensation in the urban areas along the Israeli Mediterranean seashore. In order to examine the thermal sensation at street level during the 1920s and 1930s, a series of summer and winter climatological measurements were taken in the years 2010-2013 and compared to historical climatic data from the 1920s-1930s. The historical city structure was then reconstructed virtually and the climatological measurements for 2010-2013 were fed into the RayMan model to produce thermal comfort information (PET, Physiologically Equivalent Temperature). A main finding of the study is that in summer the duration of “hot” and “very hot” heat stress was double in eastwest oriented streets compared to north-south ones. Furthermore, in the winter, higher H/W ratios can increase cold thermal sensation in streets with the same orientation by up to 10 °C PET, due to shading. Finally, the results show that solar radiation has a greater effect on thermal sensation than wind velocity both in summer and winter seasons. Consequently, the Geddes Plan created improved thermal sensation in the main streets of Tel-Aviv, which are north-south oriented, and provided for greatly improved micro-climate conditions, in spite of the critique that Tel-Aviv “turned its back to the sea”.