From Garbage to Green Park

　　Sophisticated technology employed to transform a Beijing rubbish dump into an ecological garden By Ni Yanshuo

　　Li Dong could not hide her surprise when she returned to her hometown from California. Havingbeen away for four years， she was amazed by thetransformation that Dongheyan Village， located nearthe Yongding River in southwest Beijing’s FengtaiDistrict， had undergone.

　　“I could not believe my eyes when I first came backhere. You would feel the same if you knew what thisplace was like before，” she told ChinAfrica.

　　Li’s hometown has been transformed into a massivescenic park， where the Ninth China (Beijing) InternationalGarden Expo (Beijing Garden Expo) is being

　　held from May 18 to November 18， 2013. Insidethepark， a variety of gardens， including some in Europeanand African styles， can be seen in a colorful profusionof flowers， trees， shrubs and water features.

　　“It was amazing to see all the amazing landscapeshere. You know， when I left here four years ago， thisplace was full of garbage，” said Li， who was particularlyimpressed by the changes in the Splendid Valley area.

　　Li still recalls how garbage and sand used to fly around the area when the wind blew. “But now， peoplehave a totally different view in the same place，” shesaid， already on her fourth visit to the Garden Expowithin 10 days of its opening to the public.

　　A dramatic change

　　Li is not the only person pleased by the great changesin the Splendid Valley area. Zhang Jianhua， Directorof the Beijing Garden Expo’s Media Service Department，is equally proud of the developments.

　　“We have turned a foul and rotten area into a beautifulplace. I hope this can serve as an example in termsof how to improve ecological environments in China，”Zhang told ChinAfrica.

　　According to Duan Muqi， one of the designers whoworked on the Beijing Garden Expo， Splendid Valleywas the expo’s greatest challenge in terms of designand construction. “This was a big pit about 30 metersdeep， covering 24.3 hectares， and filled with garbage，so we had to take into consideration the special landformsin different places tomake them into parts of thelandscape，” he said.

　　After careful research，Duan and his colleaguescame up with a plan to makea sunken garden surroundedwith rock features and waterfalls.“More importantly， weused waterproofing technologyto prevent garbagepollutants from spreading，”he said.

　　Workers first putwaterproofingmaterials on the pitsurface and then added soiland water to restore its basicecological environment. Afterthis， suitable plants wereselected to grow in the valley.“The construction of Splendid Valley is an excellentexample of combining ecological restoration withan environmental upgrade，” said Li Jinlong， a professorat Peking University’s College of EnvironmentalSciences and Engineering， adding that the projectcan lend experience of ecological restoration to otherplaces.

　　The work done for the Beijing Garden Expo is notthe first time that a wasteland was transformed intoa garden in China. Shanghai Chenshan BotanicalGarden， which was opened to the public in 2011， wasconstructed on a deserted mine. After its ecology wasrestored and pollution prevention measures were putin place， its original mining pits， waste water pools andcliffs were renovated into a distinctive landscape. Today，it is the botanical garden with the most diversifiedplants in east China.

　　Benefiting locals

　　“In fact， from the moment westarted constructingthe expo in 2009， we wanted to make it a model ofenvironmental improvement and ecological restoration，”said Duan.

　　Since 1997， the China International Garden Expo，which is held every second year， has been held in eightother cities in China. These expos were all held in placesthat originally had a good ecological environment.

　　When Beijing was given the opportunity， it proposedtwo places to hold the expo： One was a hilly areawith good ecological environment in western FengtaiDistrict. Covered with thick vegetation， technically， thiswas the best place to hold a garden expo. The otheroption was the landfill near Yongding River， which wasultimately selected.

　　“The major reason is that doing so would helprestore the ecological environment in the entire areanear the Yongding River and also benefit local people.

　　This work is one of the greatest innovations in thehistory of the China International Garden Expo，” saidDeng Naiping， Director of the Organizing CommitteeOffice of the Ninth China (Beijing) International GardenExpo.

　　The Beijing Garden Expo covers an area of 513 hectares，including 267 hectares of land and 246 hectaresof water. It consists of 47 gardens constructed by 69Chinese cities and 34 international gardens built by 37cities and organizations from 29 countries， includingpavilions from African countries， such as the Sudanese，Ethiopian， Cameroonian and Egyptian pavilions.

　　“Thanks to the designers and constructors，the former landfill is now a beautiful landscape alongthe Yongding，” said Deng during his address at theexpo’s opening ceremony on May 18.

　　Regarded as the mother river of Beijing， theYongding River and its surrounding area has benefitedenormously from the Beijing Garden Expo， particularlyin terms of ecological restoration.

　　“Sustainable social and economic developmentin Beijing， especially in Fengtai District， cannot beachieved without a good ecological environment.

　　Restoration of the ecological environment alongthe Yongding River benefits local people as the projectcan purify water and air， protect biodiversity and boosttourism and service industries，” said Li.

　　Sci-tech power

　　According to a China Association for Science and Technology press conference in early June， scienceand technology play an important role at the expo.

　　“Actually， science and technology have helped usgreatly in planning theexpo，” said Duan. One ofthe problems is that theexpo will run from May toNovember， but some ofthe flowers in the gardensdo not blossom duringthis period. To solvethe problem， scientistshave taken a varietyof measures to ensurethat visitors will see lushgardens no matter whenthey attend the expo.

　　These measures includethings such as freezingpeony seeds to delay theflowers’ blooming period，which normally occursin April， to May， June andeven July； they have alsochanged the growinglight and temperatureof water in Beijing， scientists designed an innovativerainwater collection system for the expo.

　　“This system can collect the rain that falls in thepark to irrigate the landscape，” said Liu Xueyan， anengineer at the Beijing Institute of Water.

　　Rainwater is filtered through collection tanksembedded inside the landscapes and permeablematerials on the paths and squares inside the expo，before it goes to an underground reservoir. The watercan then be used to irrigate expo plants.

　　Solar photovoltaic power generation technologyhas also been widely applied on the expo roofs.According to Guo Xinghai， General Manager of BeijingGreenery Energy Co. Ltd.， advancements made insolar photovoltaic power generation technology inChina allow such technology to be widely used. Thisphotovoltaic power is mainly used for lighting buildings，road lamps and in low-voltage current systems.

　　To recharge the electric vehicles thatcarry passengersaround the expo， a wind-solar hybrid systemwas also built. Each wind-solar hybrid plant has a windturbine and a solar photovoltaic panel， which canutilize both wind and solar resources to ensure stablepower generation. Conservative estimates show thatthis system will generate at least 15，000 kwh of electricityduring the six-month expo period.

　　“This expo was constructed on a deserted areaand should be environmentally friendly. By usingenvironment-friendly technologies， we have totallychanged the ecological environment here，” saidZhang.CA

　　niyanshuo@chinafrica.cn

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