綠色層頂

David+Feeley+張曉敏

Who gets to plan the cities of the future？ You do！ It may all start with the roof over your head. Roofs of future cities will look and feel cooler. "Green" plant covered and "Cool" white or pastel1） roofs have long been popular in Europe， the Middle East， and Canada. Now roofs that look more like meadows than asphalted2） streets， plus those that paint a pretty pastel picture， are becoming part of the "greening" of America.

未來的城市由誰來著手規劃？由你來！這一切或許都可以從你頭上的屋頂開始。未來城市的屋頂看上去和感覺上都將會更涼爽。在歐洲、中東和加拿大，一直都很流行將屋頂種滿“綠色”植物并且刷成“涼爽的”白色或是柔和的色彩。現在，那些看上去更像草坪而不是瀝青馬路的屋頂，還有那些畫著一幅美麗的彩色圖畫的屋頂正成為美國“綠化”的一部分。

Jackman School

Students， teachers and parents at Jackman Avenue Public School in Toronto， Canada， had a problem： heat. They knew air conditioners weren't an eco-friendly solution because they waste energy and just heat up the neighborhood. So， looking to the future， they used ultraviolet3） （UV） film4） and solar blinds for their windows， and added ceiling fans and shade trees. They also put a Green Roof on the school.

The Heat Island Effect

Cities full of buildings with Jackman School's problem are in big trouble！ The United States Environmental Protection Agency （EPA） says that due to the "Heat Island Effect"， cities and suburbs are 2 to 10 degrees Fahrenheit （F） hotter than nearby country areas. Tall buildings with flat roofs and narrow streets trap heat from cars， factories and air conditioners. This adds to global warming. In cold， northern locations， cities may stay a little warmer in winter， but most of the year they need more energy to get cool.

Cities have other problems too. They have increasing levels of pollution， which make people sick， and rainwater from roofs washes through city streets without becoming part of our needed watershed5）. How can the 3.3 billion people now living in our cities survive in the future as temperatures climb higher due to global warming？ Bob Fittro， of DesignandBuildwithMetal.com， says green roofs—those with a plant covering—can certainly help. "Where roofs are flat， plant covered systems have been shown to keep buildings cooler inside， and as an added benefit they turn roofs into enjoyable park-like spaces，" he says.

Green Roof Pros and Cons

On a summer day， the temperature of a roof can reach 140 to 190 degrees F. Think about it： an egg fries in a 158-degree F pan！ Covered with grass to absorb sunlight， the temperature of that same roof wouldn't rise above 77 degrees F. After a couple of years， plant roots get so dense that they act like a warm coat， lowering heating costs in winter， even when that coat is more brown than green.

Balmori Associates， an urban landscape design firm based in New York City， built a 35，000-squarefoot green roof atop Silvercup Studios in Queens， New York. The firm found a 30～50 percent reduction of energy use for climate control for the building in the summer and nearly a 50～100 percent reduction in spring and fall.

You can breathe deeply with a green roof， too， because they clean the air by catching particles of pollution， and use carbon dioxide to make more oxygen. They also absorb traffic， machinery and airplane noise. So future cities with Green Roofs will be cooler， cleaner and quieter.

Storm water is stored by a green roof and its plants return water to the air. Extra water is cleaned and cooled by plants before it leaves the roof. Jackman student research showed their green roof had about 75 percent less runoff water than before adding a green roof.

Balmori Associates planned a green roof for an environmentally progressive residential tower in New York City， called The Solaire， which stores rainwater not absorbed by its plants， along with the building's grey water6）， in a basement cistern7） where it is filtered and reused to irrigate8） nearby parks as needed.

Owners of the Fairmount Waterfront Hotel in Vancouver， Canada， save about $30，000 a year by using the herbs and vegetables growing on the building's roof.

Green roofs also are healthy， safe places to relax and play in a crowded city. Some local plants and animals even find a home there.

Making It Green

（and Yellow， Red and Brown）

A rooftop is a tough place to live. There are high winds， extreme hot and cold temperatures， and usually very little water. For its green roof， the Jackman team chose local plants with brightly colored flowers and shallow roots. Bergamot， yarrow， asters， geraniums， daisies， coneflowers and four kinds of sedum9） are included. Their "green" roof is actually shades10） of yellow， red， purple and brown. The Silvercup Studios' green roof has 20 different sedum varieties growing in a pattern of green strips and blocks that bloom in yellows， reds and pinks from spring to fall.

Tomorrow

Many groups have grand plans for future cities. One is a project by Balmori Associates called Shanghai Bund in China， where they propose to create a 20-meter green zone connecting the city to Huangpu River. With engineered islands to clean and filter water and generate energy， Shanghai Bund will be a zero-waste11） landscape. You'll see plenty of green roofs there.

The best choices will improve our lives and the cities we live in by respecting each other and the planet we so depend upon.

杰克曼學校的故事

加拿大多倫多杰克曼大街公立學校的學生、老師和家長們之前碰到過一個難題：炎熱。他們知道開空調并不是個環保的方法，因為空調浪費能源，只會使居住區變得更熱。所以，放眼未來，他們給窗戶貼上了紫外線薄膜，裝上了遮陽百葉窗，還安上了吊扇，栽了遮陰樹。他們還為學校建造了綠色屋頂。

熱島效應

不少城市滿是面臨杰克曼學校這種難題的建筑，大麻煩也由此而來！美國環境保護署宣布，由于“熱島效應”，城市和郊區的溫度會比鄰近的鄉村地區高出2～10華氏度（編注：1華氏度約等于17.2攝氏度）。平頂高樓和狹窄的街道令汽車、工廠以及空調散發的熱量無法外散，而這又加劇了全球變暖。美國那些位于北部寒冷地區的城市在冬天也許仍能稍微暖和一些，但是一年中的大部分時候它們需要更多能源來降溫。

城市還面臨著其他問題。城市里有越來越嚴重的致人生病的污染，而且順著樓頂流下來的雨水從城市的街道沖刷而過，卻沒有成為我們所需要的集水區的一部分。隨著全球變暖導致氣溫不斷升高，現在全球城市里居住的33億居民未來要如何生存下去？DesignandBuildwithMetal.com網站的鮑勃·菲特羅稱，綠色屋頂——那些有植物遮蓋的屋頂——無疑是一大助力。“對于平頂的建筑，有植物覆蓋的系統已經表明可以讓建筑的內部更加涼爽，另外還帶來一個額外的好處，就是把樓頂變成了像公園一樣賞心悅目的地方。”他說道。

綠色屋頂的利與弊

夏日的白天，屋頂的溫度可以達到140～190華氏度。想象一下：一顆雞蛋在一個158華氏度的煎鍋里煎著！同一個屋頂，如果上面鋪了草坪來吸收陽光，其溫度將不會超過77華氏度。幾年之后，植物的根長得夠密實，還可以當做房子的保暖外套，降低冬天取暖的費用——即便那時這件“外套”更接近棕色而不是綠色（編注：指冬天植物葉子變黃時）。

巴爾莫里建筑事務所是一家總部位于紐約市的城市景觀設計公司，該公司在位于紐約皇后區的銀杯工作室頂部搭建了一個35000平方英尺的綠色屋頂。這家公司發現，該建筑控制溫度的能耗有所減少，夏天能耗減少了30%～50%，春秋兩季則減少了近50%～100%。

擁有了綠色屋頂，你還可以深呼吸，因為這樣的屋頂可以通過捕捉空氣中的污染顆粒來凈化空氣，并能利用二氧化碳來制造更多的氧氣。它們還可以吸收交通、機器以及飛機帶來的噪音。所以，未來有綠色屋頂的城市將會更涼爽，更干凈，也更安靜。

雨水會被綠色屋頂貯存下來，再由屋頂的植物送回到空氣中。多余的雨水會在離開屋頂前被植物過濾和降溫。杰克曼的學生研究顯示：他們加了綠色屋頂后，屋頂雨水流失量比之前減少了約75%。

巴爾莫里建筑事務所為紐約市一幢環保方面較為先進的住宅高樓設計了一個綠色屋頂。這幢高樓名為索拉里，它能將沒有被屋頂植物吸收的雨水以及樓內的廢水都存入地下室的蓄水罐里。這些水會在這里經過過濾，然后在需要時被用于澆灌附近的公園。

通過利用酒店屋頂生長的香草和蔬菜，加拿大溫哥華費爾芒特海濱酒店的擁有者一年就可省下大約30000加元。

在擁擠的城市，綠色屋頂還是個放松、游玩的好去處，健康又安全。當地的一些植物和動物甚至還會在這里安家。

讓屋頂變成綠色

（和黃色、紅色和棕色）

在屋頂生存不易。那里有強風，有酷熱或嚴寒，而且通常沒什么水。杰克曼學校的設計團隊給他們的綠色屋頂選擇了當地一些花朵顏色亮麗和根須較淺的植物，有佛手柑、歐蓍草、紫苑、天竺葵、雛菊、金花菊，還有四種景天屬植物。他們的“綠色”屋頂實際上有黃色、紅色、紫色和棕色。銀杯工作室的綠色屋頂則有20種不同的景天屬植物，種的時候排成了綠色條紋和不同的方塊組成的圖案——從春天到秋天依次開出黃色、紅色和粉色的花兒。

綠色屋頂的明天

許多組織對未來的城市都有宏偉的規劃。其中之一就是巴爾莫里建筑事務所在中國規劃的一個叫做上海外灘的項目。巴爾莫里建筑事務所提出建造一個20米長的綠色區域來連通上海和黃浦江。有這些人工設計的小島來過濾清潔水資源并產生能量，上海外灘將會成為一個零廢棄的景觀。你在那兒會看到許多綠色屋頂。

這些最好的選擇將會通過對彼此的尊重以及對我們如此依賴的地球的尊重來提升我們的生活品質，改善我們生活的城市。

1.pastel [?p?stl] adj. 柔和的；淡的（指顏色）；彩色粉筆畫的；彩色蠟筆畫的

2.asphalt [??sf?lt] vt. 用瀝青（或柏油）鋪（路）或覆蓋（屋頂）

3.ultraviolet [??ltr??va??l?t] adj. 紫外線的

4.film [f?lm] n. （塑料）薄膜

5.watershed [?w??t??ed] n. （森林地帶的）集水區

6.grey water： 洗盥污水；不凈化就可再利用的家庭污水

7.cistern [?s?st?n] n. 地下蓄水罐

8.irrigate [??r?ɡe?t] vt. 灌溉

9.sedum [?si?d?m] n. 景天屬植物

10.shade [?e?d] n. 色調

11.zero-waste： 零廢棄，一種新型理念和設計原則，方法是運用可持續發展原則，管理資源和廢棄物，目標是消除廢棄物及有毒物質排放，減少所需資源，實現資源的再利用和再循環。

To Build a Green Roof 如何打造一個綠色屋頂

Are you thinking that your school should have a green roof？ There are lots of important considerations. Green roofs that will be intensely planted with trees and shrubs， and have people walking on them， should start with a strong， flat roof. This should be covered with waterproof， insulating， root-blocking barriers. Follow this with both water drainage and filter layers. Then add soil and cover it with a tightly woven material to keep wind from blowing the soil away. Poke your plants through this cover into the soil. Leave the roof edge and corners plant-free to prevent wind damage.

Isn't there an easier way？ Yes. Light-weight roofs can be made of two-to-four-inch thick pre-planted blocks snapped together and placed over water and root barriers. Planted with short， hardy plants， like sedums， these green roofs can neatly cover even sloped roofs.

你是不是在考慮你的學校也應該有個綠色屋頂？有許多重要的事情需要考慮。一個將要種植密集的樹木和灌木、還能讓人在上面行走自如的綠色屋頂首先應該是堅固而平坦的。在它的上面還應該鋪上能防水、隔熱、阻絕植物根系的多層阻隔物。緊接著，要在上面鋪設排水系統和過濾層。然后再蓋上土，并給土層罩上一層編織緊密的織物，防止風把土吹走。透過這層外罩把你的植物種進土里。要把這個綠色屋頂的邊緣和角落都空著，以防大風造成破壞。

有更簡單一些的方法嗎？當然。可以制作輕型屋頂：將2～4英寸厚的提前種好植物的板子拼在一起，然后把它放在可以防水并能阻絕根系的阻隔層之上。要種一些低矮的耐寒植物，比如景天屬植物，這樣的綠色屋頂就連有點兒傾斜度的屋面都可以很好地遮蓋。