Developing an Urban Digital Twin for Environmental and Risk Assessment: A Case Study on Public Lighting and Hydrogeological Risk

Improvements in immersive technology are opening up new opportunities for land management and urban planning, enabling the creation of detailed virtual models for examining and simulating real-world short-, medium-, and long-term scenarios. The goal of this research is to present the creation of an urban digital twin based on a virtual reality city replica, that models and visualizes the urban environment in three dimensions using advanced geomatics techniques and IoT technologies. The methodology focuses on two case studies that utilize environmental analysis and virtual simulation: assessing hydrogeological risk and evaluating public light pollution. The Cesium platform was employed to build high-precision 3D models based on topographic, meteorological, and infrastructure data. The proposed methodology calculated a correlation between light pollution and CO 2 equal to 0.51 and a correlation between precipitation, slope, and risk area higher than 0.80. The most critical and high-risk classes are as follows: Dense Discontinuous Urban Fabric, Roads and Associated Lands, Pastures, and Forests. Results show how an urban digital twin can be a powerful tool for monitoring and territorial planning, with concrete applications in the public and risk management fields. This study also highlights the importance of geomatics technologies in the creation of realistic and functional virtual environments for the assessment and sustainable management of urban resources.