The contribution of urbanisation, climate and mitigation strategies to the urban meteorology: A case study for Melbourne (Australia) and Toulouse (France)

(2010 – current)
Dr Matthias Demuzere

This post-doctoral position considers the implications of urbanisation, climate change and mitigation strategies on the urban climate in Melbourne (Australia) and Toulouse (France). Both cities are interesting cases to study contrasting cases of city planning: Australia for example has made great efforts to increase usage of roof materials with high albedo values, which heavily contrasts with old West-European cities such as Toulouse. Moreover, this choice offers the possibility to study similar mitigation strategies such as water sensitive urban design and its effect on urban climate in climatic regimes that are shown to suffer a larger heat stress intensification compared to urban areas in more moderate climate regimes.

The first part of this project involves an off-line evaluation of the new urban module of the Community Land Model (CLM4.0), for the period February 2004 to February 2005, using meteorological boundary conditions of atmospheric wind, temperature, specific humidity, precipitation and solar and long-wave radiation provided by measurement sites in Preston (Melbourne) and Toulouse. Flux measurements from the urban flux towers in both sites provide the necessary and invaluable evaluation dataset. This will allow assessment of the strengths and weaknesses of the urban module in clm4.0.

In a second step, a general set of three experiments will be undertaken with CLM4.0 coupled to the regional climate model COSMO-CLM for the two selected cities:
A. Quantification of the effect of pre-industrial and present-day urbanisation on the local climate
B. Quantification of the effect of different urban development scenarios as the climate changes
C. Similar as experiment B, but including mitigation strategies in the urban development scenarios

The range of mitigation strategies used in experiment C will be tested using the COSMO-CLM – clm4.0 modelling framework in order to address the possible unfavourable urban conditions due to climate change or thoughtless city planning. The main strategies are urban forestry (curb side planting and/or open-space planting), living roofs, light roofs and surfaces, and irrigation/stormwater retention for heat mitigation.

By looking at past, present and future development scenarios, this research will provide insight into the impacts of  large built-up areas on the urban climate. At the same time,  any large-scale warming likely to occur under a changing climate will also be accounted for. Moreover, the outcomes from this research project will strengthen scientific proof to support the use of mitigation strategies and will help policy makers to decide which development strategies to implement in order to support sustainable and pleasant urban areas in a cost-effective way.

For more information, click here (detailed project proposal).

Research Foundation Flanders (FWO)

Publications (link)

Project P3 (Green Cities and Microclimate)Cities as Water Supply Catchments Program