Talks and Poster Presentations (with Proceedings-Entry):
A. Mahdavi, K. Kiesel, M. Vuckovic:
"A Framework for the Evaluation of Urban Heat Island Mitigation Measures";
Talk: sb13 -munich - Implementing Sustainability - Barriers and Chances,
- 2013-04-26; in: "sb13 -munich - Implementing Sustainability - Barriers and Chances",
G. Hauser, T. Lützkendorf, N. Eßig (ed.);
Fraunhofer IRB Verlag,
In the last few years, the general awareness concerning the urban heat island (UHI) phenomenon has been steadily rising. Likewise, a deeper understanding is emerging concerning UHI's farreaching implications for microclimate, energy use, and human requirmente pertaining to health and comfort. In this context, in many cities around the world adaptation and mitigation measures are being conceived - and, in a number of instances implemented - that are expected to address the negative impacts of UHI phenomena. Such measures generally require a considerable level of effort and investements. Hence, their effectiveness should be assessed and evaluated a priors and systematically.
As a contribution to the present efforts in this direction, this paper presents results of an on-going research project which investigates the urban heat island phenomena in the Central European area. The proposed methodology can be seen as a contribution tothe UHI issue in terms of reducing the negative effects of this phenomenon. Moreover, the present paper introduces a systematic framework for the evaluation of urban heat island mitigation measures.
The aforementioned UHI project involves the consideration of potential pilot actions toward mitigation of the urban heat island effect. A spatial domain associated with the area in which such a pilot action is envisioned, could be defined in terms of an U2O. These well-defined segments may share characteristic features in view of geometry, massing, or other aspects of the physical structure. In order to predict, estimate and verify the effect of urban heat island mitigation actions on reduction of urban heat island intensity, we need to express such actions in terms of changes that they introduce in an U2O. We thus need a structured approach to systematically capture the essential geometric and physical features of an U2O. Once U2Os and their respective variables are defined, potential mitigation measures may be expressed in terms of respective changes to the variable attributes. Once the specifics of an envisioned mitigation measure are determined (specifically, in terms of implied changes in the U2O variables), their impact can be estimated based on appropriate calculation tools and modelling methods.
Given its complexity, we are providing the summary of the proposed framework by listing the steps that will provide us meaningful results:
i) Definition of "urban Units of Observation" (U2O): These are properly bounded areas within an urban setting selected as the target and beneficiary of candidate UHI Mitigation measures.
ii.) Description of the status quo of U2O in terms of a structured set of geometric and physical properties. The first set includes variables such as built volume ratio, urban envelope factor, etc. The second set captures information on surface albedo, admittance, etc.
iii.)Specification of the existing UHI effect intensity in terms of a set of pertinent variables (e.g. the difference between urban and rural temperatures).
iv.)Specification of the candidate mitigation measures in terms of projected changes to the geometric and/or physical properties captured in step ii above.
v.)Predicitve assessment of the effect of mitigation measures using empirically-based and/or numeric micro-climatic models.
vi.)Expression of the mitigation measures' impact in term of predicted changes in UHI effect intensity variables mentioned under step iii above.
vii.) Overall evaluation of the mitigation measures' effectiveness on the basis of modelling results together with their estimated financial and logistic ramifications.
none - see english version
Urban Heat Islands, Mitigation and Adaptation, modelling, evaluation
Project Head Ardeshir Mahdavi:
Monitoring and modeling of the urban micro-climate
Created from the Publication Database of the Vienna University of Technology.