3D city models to simulate the spreading of electromagnetic waves in urban areas, and thus accurately plan the deployment of telecommunications (mobile telephony, wifi) wireless networks.

Electromagnetic field exposure in Nîmes – source: Siradel

Based on geostatistical data (ex: use of transport, data of consumption) and demographic (ex: number and average age of the residents and workers of the district), the hotspots for the use of these networks can be predicted, to optimize the coverage of the networks.

In parallel, the exposure of populations to these electromagnetic waves can be objectively calculated in all urban areas, outside as well as inside buildings. So, some base stations can be moved, in order to minimize electromagnetic pollution near the most vulnerable places (crèches, schools etc.).

Prerequisite: Model city LoD1 3D, positioning of base stations.

Initiatives & links

Siradel company

• Exposure of the population to the airwaves radio and recommendation of positioning of base stations (case study, paper)
• Advanced model of propagation of radio waves

Brussels environment

• Atlas environment: 3D Simulation of the electromagnetic field (webgis)

Urban forms, surface materials, the presence of vegetation and water bodies, and the concentration of human activity have a real influence on the urban microclimate. In particular, the dense urban morphologies are "traps for solar and thermal radiation" while the surfaces of the frames absorb and store some of this energy.

Screenshot software CitySim – source: Kaemco

This microclimate is more often characterized by higher temperatures in the Center cities than on their outskirts, called urban heat island phenomenon. In the winter, so these are milder temperatures and thus consumption of heating lower than in rural areas, but also of the peaks of heat stressed in the summer, sometimes suffocating. More than just a source of thermal discomfort for city dwellers, urban heat island is moving to the center of political and social concerns, in order to limit the health impacts of heat waves that should multiply in temperate zones in the coming years according to the IPCC.

Accurately predict the micro-climates linked to new urban developments is therefore crucial. Take into account all aspects and their interactions requires a combination of quite comprehensive and complex physical models (models thermo-radiatifs, air, évapo-transpiratifs and anthropogenic effects). These are based on the 3D geometry of the buildings, their construction materials and its mode of occupation, but also data on their environment, vegetation, soil, human activity (especially transport) etc… all data that can deliver city CityGML models.

Schematic Cup of visualization of temperatures in 2008 for a night of heat – source: Group DESCARTES

Initiatives & contacts

SOLENE, development of a tool for simulations of the urban microclimate platform.

• Author: School of architecture of Nantes (NICHE)
• Contacts: Thomas Leduc, Marjorie Musy.

CITYSIM, urban energy simulation software

• Author: School Polytechnique Federal de Lausanne, now managed by Kaemco
• Contact: Silvia Coccolo, Jérôme Kaempf.

3D city models combined with the digital terrain models (DGM) offers a data base adequate to the calculations of propagation of sound waves in urban areas.

Map of Zurich noise – Source: City of Zurich

  Such studies are required in particular by the European 2002/49/EG directive on noise in the environment to assess the levels of noise pollution and implement the necessary improvement actions. The agglomerations of more than 100.000 inhabitants are required to perform such studies every 5 years.

For new urban development, this method based on 3D models to optimize plotted of the axes of transport and urban forms in order to limit noise pollution.

Prerequisite: model 3D city (enough LoD1) including DGM, data traffic, railroad and air as well as from industrial activities. Optionally: Data for construction of buildings and urban infrastructure (in particular their reverberation coefficient).