Tackling uncertainty in combined visualizations of underground information and 3D city models

Cities are under constant development. They are characterized not only by their surface constructions like buildings and traffic infrastructure, but also by their underground structures. Besides human-created lifelines, tunnels and quarries, there are also diverse geological formations. Underground information contains a lot of uncertainty by nature, because measurements provide information along drilling lines only. Additionally, man-made structures are often hardly documented. In this paper we will present ways to visualize such uncertainty in combination with exact surface structures from 3D city models in order to assist stakeholders in making decisions. We will evaluate existing techniques and describe the requirements imposed on uncertainty visualization.