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Wednesday, June 1, 2016, 08:53

A new dimension in the space war

By Wang Yuke

As Hong Kong struggles with land shortage, the need for precision planning grows. A team of local researchers believes it has come up with a solution to all the conflicts. Wang Yuke reports.

A new dimension in the space war

What will the future look like? We can get a peek with three-dimensional (3D) mapping software that can foretell the impacts changes will have on any given environment. It can foretell effects on prevailing winds on the amount of sunlight, predict effects on the populated regions brought about by any emergency and natural disaster, and even make sense of the outcomes for Chinese white dolphins’ habitat in light of Hong Kong’s third runway development.

It can predict which hospitals are most likely to be cut off from access in a flood. It adds up to an invaluable aid to urban planners and property developers — possibly even to provide solutions to the endless wrangles over new developments in our cheek-by-jowl city, starved for affordable housing.

The Novel Integrated 3D Mapping Mode, developed by a team of scientists at the Hong Kong Polytechnic University (PolyU), was acclaimed with a Gold Award at the 44th International Exhibition of Inventions in Geneva in April.

The key, says Professor Wu Bo who headed the team at PolyU’s Department of Land Surveying and Geo-Informatics, is precision measurement.

In the case of a crowded city like Hong Kong, where buildings practically tumble over one another, he cites examples of the many rows arising between developers and nearby residents. People see their comfortable living arrangements torn apart by new developments that can impede sunlight, spoil the view, block the air flow, and generate nightmarish traffic.

Wu thinks that many disputes can be resolved in advance, if developers and urban planners use the 3D mapping and modeling system.

The precision is obtained by combining aerial imagery, which produces accurate horizontal models, with laser imagery which gives more precise measurements of vertical planes.

The system allows greater accuracy and predictability over a wide range of environmental considerations.

Property developers and urban planners can solve a lot of potential problems by examining proposed buildings to ensure proper ventilation, pleasing sightlines, efficient distribution of sunlight, and smooth ingress and egress of traffic flow, said Wu.

A new dimension in the space war
Wu Bo, professor, Department of Land Surveying and Geo-Informatics, Hong Kong Polytechnic University

He noted a case in a Sha Tin neighborhood. Proprietors in nearby buildings complained a newly built high-rise complex blocked the breezes and interfered with TV signals. Wu said his team measured wind velocity, 1.5 meters above ground. The team combined 3D mapping and modeling, rendering a ventilation simulation measured in tens of meters. They created a color coded map, showing how the winds affected each floor of every nearby building. The study revealed that some buildings at higher elevations received no breeze, leaving them poorly ventilated and stuffy. Lower levels were virtually blasted by wind velocities measuring between 4.675 m/s and 5.95 m/s.

“The 3D technology enables us to quantitatively evaluate how serious the problem is and even avoid it in the first place,” remarked Wu.

The technologies always have been applied separately, so that over the past 15 years, a large body of aerial images and laser scans has been accumulated. These have produced significant variances of measurement in data from identical locations, Wu declared.

“If the 3D system is made accessible to the general public, people will be able to take a virtual tour of any apartment they fancy. Before settling payment, they can get a sense of the ventilation, natural lighting, heat distribution, outdoor noise and scenic views,” said Wu.

Informed of any defects of potential problems that exist in the apartment, buyers have a chance to weigh their choices. They might eventually give it up, due to inadequate sunlight, traffic noise, poor ventilation or an unappealing view.

Even flawed apartments, said Wu, can be modified, by adding more light to compensate for insufficient sunlight. Better heating can be installed if the 3D model reveals the rooms are poorly insulated. This can be determined by examining the window to façade ratio.

Wu said his team experimented with 3D mapping and modeling system on a new office building at PolyU, to measure noise levels on different floors. Team members measured the noise level on the ground, followed by simulating the noise level at certain floors by using 3D modeling. Then noise distribution for the whole building was mapped out. The modeling results largely validated actual experience.

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