Urban planning becomes three-dimensional

3D simulations as a key to the sustainable development of urban settlements

Cityscape in 3D © Ekkehard Matthias
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In order to make urban areas fit for the future and climate change, urban planners are increasingly using three-dimensional virtual models. Because with their help, they can calculate planning variants without great effort and compare. At the same time, the clarity compared to the previous 2D plans increases significantly even for inexperienced card readers. The simulations can range from simple "blocks" with no underlying terrain to detailed digital models with projected photos and detailed terrain.

"One or the other picture of flooded cities in coastal areas, everyone has seen before, " explains Ekkehard Matthias of the Hamburg State Geoinformation and Surveying. "Most of these representations are based on contour lines whose individual layers - depending on the assumed water level - are colored differently blue. This is very clear, but not always correct, "says Matthias to report.

Altitude measurement - but correct

Because modern processes not only consider the natural heights but also artificial structures such as dykes or other flood protection systems. The 3D simulations incorporate detailed field surveys, which were previously obtained using state-of-the-art laser scanning or terrestrial surveying. In interaction, this information then provides an accurate insight into the congestion and runoff of heavy rainfall as opposed to a "normal" tide.

Building design in 3D © Ekkehard Matthias

"The better we model the terrain and building shapes, the more accurate the simulation results will be. This is similar to the bodywork development of cars in the wind tunnel, "explains Matthias the benefits of the 3D models. Conclusions can be drawn not only for the optimal dike construction but also for the building design. "For example, in Hamburg's HafenCity, all buildings are built on so-called terps. These are small hills that are supposed to prevent the ingress of water into the lower floors in a storm surge ". Even the change in wind direction and strength can be included in the simulations. This is especially important when planning variants of buildings are exposed to the assumed weather.

Simulation of noise and quality of life

But not only the weather, the noise is also an environmental impact, which is particularly noticeable in cities. This is where the EU directive on ambient noise has been taking effect for some time. Many jobs are currently in Germany in the process of recording the actual state of noise pollution, says Matthias. The aim is to use three-dimensional noise calculations with stylized buildings to find the most heavily polluted areas and thus provide decision support for later protective measures. display

Residential and business building in the model Ekkehard Matthias

Changes to the skyline of the city are now frequently checked in advance on the basis of 3D models. Just as the visual relationships within the Stra enz ge: Not only the restriction of the field of view can be shown from different points of view, but also the shadows cast by the buildings. Thus, the impairment of the quality of life in cities has become largely predictable.

Facilitated planning

"These are all examples of more transparency in the planning process, " explains engineer Matthias. The biggest advantage is the ability to show clearly how the object will be- come, and what effects it can have before realizing expensive buildings. And not as abstract and difficult to understand as a 2D plan or a wooden model, but more realistic than ever before. If you do not want to do without the beloved wooden model, the digital data will continue to help you, because they can be used to derive haptic models made of plastic or wood, "smiles Matthias.

Finally, there is another aspect of sustainability. For example, valuable buildings that are listed as historical monuments can be modeled and textured so realistically that they provide good and meaningful foundations for planning in the neighborhood. Changes to existing buildings and their surroundings can then be adjusted to the overall impact. This guarantees the planners a harmonious and coordinated cityscape even before the start of realization.

If these urban planning options were recognized only a few years ago, they now find more and more supporters and imitators, "concludes Matthias. But urban development planning, especially the one that is committed to the long-term welfare of the citizens, will probably not want to do without these techniques in the future.


www.hamburg-domplatz.de/site/downloads/ 1481_32_3D_Modell_1.pdf

(Ekkehard Matthias / Free and Hanseatic City of Hamburg / Landesbetrieb Geoinformation und Vermessung, 10.08.2007 - AHE)