City planners are taking advantage of a horticulture expo to promote public awareness of environmental protection in the city of Xi'an in northwest China's Shaanxi province.

Exhibitions that showcase environmentally friendly ways of processing waste, a pavilion that demonstrates an energy-saving water recycling system and works of art that promote the frugal use of natural resources are on display at the ongoing International Horticultural Exposition in in Xi'an, the capital of Shaanxi province.

"By using visible 'green exhibits', we hope to send an invisible message to the public of what eco-friendly technology and lifestyles should be like. Hopefully, visitors will take a hint from these examples," said He Hongxing, a professor at the Xi'an University of Architecture and Technology.

Public awareness for environmental protection and ecological preservation is especially important in Shaanxi, which is home to a large portion of the Loess Plateau on the middle reaches of the Yellow River. The region is prone to ecological disasters that are caused by human activity, said He, who is also the former head of the Xi'an City Planning Bureau.

More than 15 million tourists have already visited the 178-day expo, which concluded on Oct 22. Although no statistics are available regarding the number of local residents who have visited the expo, He said he believes its impact on local ecological awareness should not be underestimated.

To ensure that visitors to the expo park are exposed to a variety of "green" technology, gardening artists and architects have been encouraged to use materials that are renewable and environmentally friendly, according to Huang Liwen, senior designer at the expo park design office.

One example is the Chang'an Tower, a 99-meter-tall Chinese-style pagoda designed by architect Zhang Jinqiu that has served as one of the expo's landmarks.

The skeleton of the structure is out of steel and recyclable glass that can be disassembled and reused, while its air-conditioning system features a ground-source heat pump (GSHP) that fewer less greenhouse gases.

The site of the expo park itself is a demonstration of the ways in which the ecology of areas that have been badly damaged by human activity can be restored, said Ma Naixi, a professor from the Department of Environmental Science at Northwest University.

The expo is being held near Guangyun Lake, which used to be a key seaport during the Tang Dynasty (618-907). However, the lake itself disappeared many years ago, and has largely been used as a landfill since then, according to Cheng Bin, a local resident and vice general manager of the Xi'an International Horticultural Park Co.

In January 2005, the city began to refurbish the lake, channeling water from a local river to fill sand pits and planting trees. The area is now carpeted in flowers and other greenery.

"By turning this wasteland into an ecological city and a site for such a large-scale expo, we hope that both the city and the public will be more aware of how to maintain the balance between people and nature," said Cheng.

Organizers also decided to refrain from using fireworks at the expo's opening ceremony. The municipal government of Xi'an has promised that the expo park will not be used for real estate development projects after the closure of the expo.

The expo site will instead be built into a theme park and reopen to the public in April next year, according to the expo's organizing committee.

The low-carbon and environmentally friendly technology exhibited at the event will be applied to Xi'an's economic and social development in the future, said Zhang Jianzheng, a municipal government spokesman, at a press briefing on Thursday.