Digital Twins at the City and Town Scale: Europe and Beyond

The last ten years have seen great strides in digital archaeological and heritage outputs, particularly with the use of three-dimensional (3D) digital documentation becoming increasingly commonplace. Methods that widen participation and increase access have led to valuable community-scale documentation, from artefacts to landscapes. As part of this workflow, the Visualising Heritage team at the University of Bradford, UK, and international collaborators, have been at the forefront of applying digital twin technologies to townscape heritage for many years. Our approach includes the use of mobile mapping technologies that were initially developed to mitigate heritage destruction and loss that had occurred through conflict and mass disasters. Our main focus has now shifted to anticipating heritage loss and ensuring that an accurate record exists for heritage assets at risk, and engaging with planners to anticipate the needs of the cultural heritage sector. In this paper we present our scalable approach, from individual buildings that have been assessed as heritage at risk, to streetscapes and broader cityscapes. In partnership with City of Bradford Metropolitan District Council, we have developed 'Virtual Bradford', one of the first open-data level-of-detail 3 (LoD3) city-scale digital twins. Virtual Bradford provides an accurate digital representation of the city centre, encompassing several conservation areas and multiple listed buildings, including landmark buildings such as City Hall, St Georges Hall and the Wool Exchange, each designed by architects Lockwood & Mawson, who also designed the nearby United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site of Saltaire, which has been the subject of additional capture and outputs. This work has produced a seamless data-rich model embracing heritage at its core while addressing the demands of the 21st century. In response to the UK Research and Innovation (UKRI) Global Challenges Research Fund (GCRF) initiative advocating cutting-edge research to address challenges faced by developing countries, we have used the latest technology to replicate and extend our approach to digital twin development for the 19th-century colonial city of Bagamoyo in Tanzania. Each project collectively represents place-based research that helps to address needs ranging from data-driven decision-making in support of local authority needs (including, as a core deliverable, forming part of the digital strategy for the City of Bradford Metropolitan District Council), to education and interpretation, tourism and the creative economy. Fundamentally these scalar approaches help to bring planning, regeneration and related decision-making to the public and other stakeholders, leading to increased topophilia that includes heritage at its heart.