A scientific development plan is the key to sustainable urban expansion and management, officials said yesterday.

Chen Xiaoli, an official with the Ministry of Construction, made the remarks at the International Conference on Sustainable Urban Development, which opened yesterday in Nanning, capital of south China's Guangxi Zhuang Autonomous Region.

The three-day event, organized jointly by the UN Human Settlements Program (UN-HABITAT) and China's Ministry of Construction, has attracted 355 delegates from domestic and overseas research institutions and government departments engaged in urban development.

The 2005 Nanning International Human Settlement Exhibition was held yesterday in conjunction with the conference.

Three parallel sessions focusing on urban governance, sustainable land use and housing development also open today.

Chen said he believes clear planning is vital for sustainable development.

"For a city to achieve balanced and sustainable development, it is a must to clearly identify the nature, size, targets and structure of development through scientific predictions and planning before efforts are made to realize all the objectives," he said.

Chinese cities have seen rapid expansion over recent years, with increasing urban economic development providing a strong impetus for regional economic development.

Sources with the Ministry of Construction indicate that there are currently 661 cities in China, with an urban population of 540 million.

However, Chen said, Chinese cities are suffering from water and energy shortages, pollution, population expansion and insufficient infrastructure.

"Economic growth, social progress and urban performance in terms of ecological environment, city image and culture must be taken into consideration for sustainable urban development," said Chen.

Executive Director of UN-HABITAT Anna Tibaijuka said yesterday that "adequate shelters for all" has become the most important objective of sustainable urban development.

(China Daily November 10, 2005)