This research was funded under the NSF Engineering - UKRI Engineering and Physical Sciences Research Council opportunity NSF 18-067. In dense urban areas, the underground is exploited for a variety of purposes, including transport, additional residential/commercial spaces, storage, lifelines, geothermal heat pump systems, and industrial processes. These uses all can contribute to changes in subsurface temperature, groundwater levels and flow. With the rise in urban populations and significant improvements in construction technologies, the number of subsurface structures is expected to grow in the next decade, leading to subsurface congestion and potentially deleterious effects to subsurface temperature and water conditions. With correct planning, subsurface temperatures can be harnessed beneficially. However, if unchecked, they can result in a high environmental and economic costs. The combination of specially packaged monitoring equipment and an open-source underground climate model developed in this project will provide a robust framework to assess underground conditions and evaluate future evolution and potential impacts. Cities, local and state governments, agencies, utilities, as well as citizens, will be able to access these tools to make more informed decisions, avoid environmentally unsustainable practices, and extract value more fairly. In the long term, awareness of the health status of the underground is a step towards sharing responsibility for its sustainable and fair use. The ultimate goal is for every city to generate reliable maps of underground climate, with the ability to understand the influence of future urbanization scenarios. The outreach strategy is focused on engaging with the wider community and the profession to raise awareness of the issues and provide tools to explore solutions.
In collaboration with researchers at the University of Cambridge, the project will develop a framework for monitoring and predicting temperature and groundwater distributions at high resolutions in the presence of underground heat sources and sinks. A low cost and reliable underground weather station using the fiber optic sensing technologies will be developed and installed at sites in the US and UK. A high-performance computing based thermo-hydro coupled underground climate change code will be developed to simulate the temperature and groundwater variation with time at the whole city scale. The main scientific deliverable from the district- and city-scale numerical simulations and the experimental temperature monitoring is a series of archetype emulators, which are defined based on the geological characteristics, above ground built environment, such as surface and buildings types, and the density and type of the underground structures. These archetype emulators will allow efficient city-scale modelling and enable application of the methodology to any other city or region with similar characteristics of above and underground built environment.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.