Practical and Theoretical Investigation of the Influence of Facade Greening on the Distribution of Heavy Metals in Urban Streets

Greening of facades is a non-expensive option to increase the amount of vegetation in urban areas. Especially in areas with dense settlement, the filtering effect of facade greening can improve urban air quality. In this paper, results from field experiments and numerical simulations are presented. Using Atomic Absorption Spectrometry the amount of heavy metals on leaf samples from seven houses in Düsseldorf (Germany) has been analysed. To understand the dynamics of particle emission and dispersion inside the urban environment, numerical simulations with ISIS Kfz [11] and ENVI-met [1, 2, 3] have been carried out. It is shown that the general mechanisms inside the street canyon and at the facade can be reproduced by the model, but the model fails to calculate some detailed characteristics found at two houses in the field experiments.