Further development of the urban bioclimate model UBIKLIM, taking local wind systems into account

Abstract

The urban bioclimate model UBIKLIM is an application model providing an assessment on the influence of urban climate on human beings. On a calm summer's day with fair weather conditions it calculates the meteorological parameters air temperature, humidity, wind velocity and short and long wave radiation based on a digital height model and appropriate land use information. These meteorological parameters determine the heat exchange conditions of human beings and thus can be analyzed with the help of the Klima-Michel model into physiologically significant terms. The result is a bioclimate map on a scale that is appropriate for climate-related planning in an urban environment. In urban areas lying in a distinct relief, a superimposed wind regime, such as a down valley wind, can modify the bioclimate considerably. Up to now it was not possible for UBIKLIM to take this situation into account. In this point UBIKLIM has been developed further, but its easily applicable character has been preserved. This has been realized, firstly by combining an orographically induced wind field with the one calculated in UBIKLIM as a function of land use esp. of urban structure, and secondly by introducing an algorithm by working out conveyance processes in the direction of the superposed wind field. UBIKLIM fills the gap between meso and micro scale models. Results of the further developed model are shown in the example of the city of Freiburg im Breisgau which is influenced by the distinct relief at the southern edge of the Black Poorest.