A team of Chinese experts will kick off an environmental "long march" next month along the country's longest river to raise the public's awareness of the acute pollution in the river.

They will start from Chongqing, travel along the river and doing research and educating people, and will arrive in Shanghai next March.

If enough attention is not given, the Yangtze River might become as heavily polluted as the Yellow River, warned experts attending the press conference last week in Shanghai.

The event, "Long March to Protect the Yangtze River," was organized by the Standing Committee of the Chinese People's Political Consultative Conference.

The Yangtze River Delta covers less than one fifth of the country's total area, but it accommodates more than one third of its population. The river zigzags through 10 provinces, cities and autonomous regions and links four industrial cities: Chongqing, Wuhan, Nanjing and Shanghai.

"As an important economic zone, China depends on the Yangtze River if it wants to be a developed country, for the river has rich water resources, transportation capacity and also biological resources," said Chen Jiakuan from Fudan University, who specializes in bio-ecology.

But what the river faces now is heavy damage inflicted by human activities.

Construction of large-scale hydro-power stations and dams have brought big changes to the river. Lakes along the river are thinning as expanding farmland has reduced the size of some lakes by half.

With a big population and fast developed industry, the delta discharges both industrial and life sewage into the river without fully treating it.

According to an investigation launched by the China Development Research Institute last year, the polluted water in the Yangtze River has affected the operation of water pumping stations in more than 500 main cities.

Shanghai, located at the lower reaches of the river, is both a victim and a destroyer. A decade ago, the city's designed ability to process the sewage was only about 15 per cent of the discharge, which means about 85 per cent of sewage was thrown into the river without proper treatment. In 2004, the processing ability could reach 90 per cent.

"What surprised me more is not the serious situation but the weak awareness of people living along the Yangtze River," said Zhang Qi, managing president of the institute which co-organizes the trip.

"So the aim of this trip is to raise people' awareness to protect the river," he added.