Multi-scale Investigation of Principal Heat Transport Processes in Subsurface Urban Heat Islands

• Applicant: Professor Dr. Philipp Blum
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2012 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 230799312

As a result of population growth and urbanization, air temperatures in urban regions are significantly elevated, which is known as the so-called Urban Heat Island (UHI) effect. To a lesser extent, research has been dedicated to the thermal impact on the subsurface. The temperature in the shallow urban subsurface slowly increases with urban development, leading to large-scale thermal anomalies underground as well. Now, are these subsurface UHIs a blessing or a curse? On the one hand, elevated ground temperatures might promote the growth of pathogens in groundwater. On the other hand, the amount of heat available in such aquifers offers a great potential to cover energy demands and/or storages in urban areas using it for space heating or cooling by means of geothermal heat pump systems. To take advantage of this potential of urban aquifers, the principal heat transport processes in the subsurface urban heat islands have to be comprehensively understood. Hence, the main objective of this research project is to examine the intensity of subsurface UHIs and to quantify all dominant heat fluxes beneath. As study sites, we selected the two cities, Zurich and Karlsruhe, to be able to distinguish between site-specific and universally valid findings. The collaborative project of the two local partners will also benefit from their complementary expertise in field investigation and simulation. The methodological framework is innovative, uses a multi-scale monitoring strategy and process-based analytical and numerical simulations in anthropogenically influenced environments, together with geophysical/hydrogeological, statistical, engineering and remote sensing techniques.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Participating Person: Professor Dr. Peter Bayer