The Need for a Reliable Map of Utility Networks for Planning Underground Spaces

Land shortage has been on the global agenda, especially in countries with high population density such as Singapore, Hong Kong and Japan. Urban expansion and rapid population growth in these countries have led to limited surface land. In order to compensate for the shortage of surface land, the spaces below the ground surface (i.e. the stratum) are being requisitioned for the purpose of utility networks installation, public usage (e.g. pedestrian underpass, shopping malls, etc.), transportation (e.g.: subway or vehicular tunnels) and private or personal storage (e.g. car garage or basement). With the development of underground infrastructure, there is a need for monitoring and mapping these infrastructures for better usage and planning for underground spaces. This paper highlights the initiative embarked on by Singapore-ETH Centre together with Singapore Land Authority (SLA) on three-dimensional (3D) underground utility services mapping. The results ultimately contribute to the establishment of a roadmap towards a reliable 3D map of utility networks in Singapore. Several case studies for utility network mapping conducted in different cities, such as Zurich (city in Switzerland), Kuala Lumpur (city in Malaysia) and Hong Kong have been used to establish best practices for underground utility mapping using ground penetrating radar (GPR). It is expected that reliable and accurate information of these underground utility networks can lead to a better understanding and management of underground space, which eventually contributes to better city planning, making the “unseen” structures become visible.