Smart city initiatives have been a driving force for citylevel dataset collection and the development of data-driven applications that benefit effective city management. There is a need to demonstrate P. ALVA ET AL. development of data-driven applications that can help in effective city management. Smart cities have humans, technology and institutions as their three elements, with the environment, energy, transportation, safety, healthcare and education as fundamental disciplines. City sustainability, infrastructure, quality of life and service to the inhabitants are enhanced by smart city initiatives. A city-scale digital twin is one of the smart city initiatives that can integrate all disciplines mentioned above and improve systems' operability on a digital platform. Urban Digital Twin (UDT) is a 3D geospatial data model of a city consisting of physical assets, multimodal sensor data and bi-directional automated dataflow. Furthermore, planning and decision support is provided by UDTs to cities in terms of their administration, infrastructure, economic development, or citizen engagement (see Figure 1).