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Light Pollution

5260 Views 3 Replies 3 Participants Last post by  Rachmaninov
Natural night sky fading away amid bright city lights, survey finds
11 June 2009
South China Morning Post

The night sky in urban areas can be 500 times brighter than in the countryside, according to the results of the first city-wide light-pollution survey.

The finding came from a 15-month study conducted by the Department of Physics at the University of Hong Kong, with the help of volunteers who measured and reported the brightness level at 200 places across Hong Kong from March last year.

Detailed findings of the study will be released today, along with a light-pollution map on the internet.

The survey found Mong Kok and Wan Chai were two of the most "light-polluted" areas, but that a natural night sky could still be found in rural areas such as Sai Kung and south Lantau.

Jason Pun Chun-shing, an assistant professor in charge of the survey, said it was the first attempt to map Hong Kong's brightness levels and the findings would provide valuable data for policy decisions to tackle the problem.

"The results are to some extent expected given our compact city designs. But we had been unsure how exactly serious the problem is. It's time for the government to do something about the problem. Otherwise, our remaining dark sky will gradually disappear," he said.

The survey was financed by the Environment and Conservation Fund, and a report would also be submitted to the government for reference, Professor Pun said.

The Environmental Protection Department said it was still studying the need for a law to regulate light pollution in the city. The study is expected to be completed by the end of this year.

In 2003, the university conducted a small-scale study that found a brightness-level difference of 30 times between the University of Hong Kong and south Lantau.

Professor Pun said all the measurements in the latest survey - generating 5,000 sets of data - were taken at 9.30pm and 11.30pm by volunteers using hand-held devices.

The study found the average brightness level in Wan Chai and Mong Kok was about 13 magnitudes per square arc-second - the unit used to measure brightness of a night sky, with larger values for darker skies. It compared to average 20 magnitudes in south Lantau and Sai Kung.

Each drop in magnitude is equal to about a 2.5 times increase in brightness. Stargazers normally regard a value of 21.6 magnitudes as the minimum natural background radiation.

Leung Kam-cheung, president of International Year of Astronomy 2009 Hong Kong League, said the findings rang an alarm bell.

"There needs to be a law to tackle the problem, and we want it to be introduced soon as it is quite clear that light pollution in the urban area spills off into the rural areas. Otherwise our next generation will only enjoy stargazing in museums," he said.

Cheung Sze-leung, astronomy officer of Ho Koon Nature Education cum Astronomical Centre, said he was astonished by the findings. "The problem seems to be far more serious than we had imagined."

Hahn Chu Hon-keung, environment affairs manager of Friends of the Earth, said excessive lighting was energy-wasteful, and many lights in the city served little functional purposes other than being decorative. The group will organise a lights-out campaign on June 21.
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Hong Kong residents up in arms over light pollution

HONG KONG, March 7 (Reuters) - Chiu Mung-ngor and her husband paid US$3.3 million for their Hong Kong flat in a luxury apartment block in 2009, lured into buying it partly by its view of the harbour.

But their enjoyment was short-lived. The completion last October of a three-storey high LED advertising billboard on the roof of a nearby shopping mall blocked the harbour view, while the billboard lights began shining into the living room and bedrooms until midnight.

Chiu and other residents complained to the mall, the developer, the apartment block's management firm, the government, politicians and activists. Nothing changed.

Now, ten parties owning a dozen properties in the building in the Tsim Sha Tsui area may launch Hong Kong's first legal action about light pollution, claiming the billboard has ruined the value of their properties as well as their quality of life.

"The beginning of October, one couple from Australia -- they loved the apartment, they come back to visit four times, decided to rent it," Chiu said, telling how three prospective tenants have been put off by the flashing billboard 250 metres away.

"Then all of a sudden, the sign comes on. So they still tried to accomodate so they asked around to see how late the sign would be turned off. Finally they decided they could not handle it."

Chiu only managed to find a short-term tenant after reducing the rent for the 1,200-sq ft flat to US$8,300 to $6,300 a month.

The action started by the apartment residents has set off fresh complaints from nearby residents about overly bright buildings.

Mary Elvin has lived in the area for 20 years and said that many residents have left because of the break-neck pace of development, causing noise, light and traffic misery.

She said she suffered for six years while the shopping mall opposite her was under construction but now faces not only the lights from the mall but also the reflection from the mirrored panels on the side of the building.

"I've got double curtains in my bedroom. I haven't got big curtains in my living room and why should I have to?" she said.

"Should we live in dungeons?"

Complaints about light pollution have risen six-fold since 2004, with the illuminations contributing to greenhouse gas emissions, said Han Chu Hon-keung, environmental affairs manager of the group Friends of the Earth.

"In Hong Kong the population has grown less than six percent in the last 10 years, but energy consumption jumped by 80 percent. What a wastage," he said.


There is no specific legislation in Hong Kong on outdoor lighting, and complaints are handled on a case-by-case basis.

Prior to 2000, flashing lights were banned in Hong Kong because they were a hazard to planes landing at the airport, which was situated in the heart of the city.

But after the airport moved to Lantau island, the government came under pressure from developers and advertisers to allow flashing decorations and billboards on buildings.

In fact, the government itself invested money in a light show that takes place around the harbour, sparking competition among building owners who began to dress up their buildings with light -- even in residential areas.

But public pressure is mounting, and on March 28 lawmaker Audrey Eu will table a motion in the Legislative Assembly for the government to consider bringing back lighting regulations.

"So far the fight was really environmentalists, who said this is really bad for the community, the energy is bad because it gives you more air pollution," said district councilor and urban activist Paul Zimmerman.

"But now we have property owners saying,'Look, listen! This is going to impact the value of my property.' Now certainly, this is where suddenly the whole of Hong Kong is very sensitive."
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藝術相片影片 控訴旺角光污染
(星島)2011年3月14日 星期一 05:30





現從事網絡設計的他決定代表居民發聲。他以「旺角路西法效應」為題,從心理學角度表現一個社會環境何以「令正常人做邊緣事」(how good people turns evil),創作四張藝術照片和兩段影片。四幅相片以旺角行人專用區為背景,再在實景相片上畫圖或添色彩,如將高樓大廈間的街道行人加上紅色,塑造血淋淋效果,「我嘗試想像該區住戶的潛在想法,表達一種報復的心態。」


記者 洪藹婷
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