‘Understanding underground climate change using numerical modelling and statistical methodologies'

CSIC Research Talk
Thursday 14th October 2021

‘Understanding underground climate change using numerical modelling and statistical methodologies: a case study for the city of Cardiff’
Dr Monika Kreitmair and Dr Nikolas Makasis

Abstract:
Heat fluxes from infrastructure in the shallow subsurface, such as heated basements, tunnels and shallow geothermal systems, have been shown to increase ground temperatures, particularly in urban areas. This increase, known as the Subsurface Urban Heat Island (SUHI) effect, can have implications on ventilation and cooling costs of underground spaces, efficiency of geo-energy systems, quality of groundwater flow, and the health and maintenance of underground structures and ecosystems. Understanding how temperature anomalies propagate and interact beneath urban areas, especially in areas with competing thermal uses of the ground, is essential for effective and equitable planning of underground utilisation. We present a case-study of the city centre of Cardiff, UK, for which high resolution data is available, to better understand the extent of the SUHI effect. A finite element numerical model of the subsurface is developed to assess the geothermal potential of the area, as well as to investigate efficiency by exploring the impact of typical modelling simplifications. A Bayesian calibration approach is adopted to infer values of key hydro-geological and anthropogenic parameters and thus obtain a clearer picture of the thermal state and potential of the ground. Research outcomes reinforce the idea that improved understanding of the subsurface, through monitoring data, accurate modelling methodologies, and suitable statistical tools, can lead to better utilisation of this shared resource and set the foundations for a more sustainable future.

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