China's Grand Canal will be proposed for UNESCO World Heritage status. Yao Minji explores the world's oldest and longest manmade waterway. First stop: Yangzhou.

A tugboat sounds its deep horn as it tows a dozen barges into a pound lock at Shaobo, a county just outside Jiangsu Province's Yangzhou City. The barges must be unlinked and rearranged to fit inside the lock. Sluice gates release water and lower the level in the lock so the barges can continue their southward journey.

Each barge has at least one person working and living onboard to guard it. Canal sailors live in small cabins, patrol the barge and hang their laundry out. Cooking smoke rises as they prepare their meals. Dogs and cats roam around or bask in the sun.

These barges have unloaded their cargo, but the dark traces on the waterline and some lettering indicate that they are coal barges from Shandong Province in northern China. When the water level falls, the gates open and the barges are pushed outside to continue their journey.

The barges are made of steel and equipped with modern machinery and cranes but they're not too different from the barges of 1,000 years ago that transported grain, salt, silk, timber and other products along the Grand Canal of China.

Back then, they were hauled by men and oxen. At one time canals ran from Beijing in the north to Hangzhou in the south, flowed as far west as Luoyang in today's Henan Province, and emptied into the East China Sea near Tianjin.

This scene near the city of Yangzhou is busy, hectic, as it was in ancient times when the vital artery knit China together and aided in its unification and governance, as well as transport of food and diffusion and exchange of cultures.

Today China plans to seek UNESCO World Heritage status for the entire canal, the world's oldest and longest manmade waterway. It once covered 3,200 kilometers.

Birthplace

Yangzhou is the birthplace of the canal, where first ditch was dug more than 2,500 years ago, around 486 BC. It was built in the Wu Kingdom to transport troops and military supplies for a surprise attack on a rival. Yangzhou was a garrison town that became splendid city of commerce and culture, equivalent to Shanghai today.

Over the years, the canal was expanded and connected into a sophisticated network that included lakes, reservoirs, locks and gates across eastern China. Achieving this north-south link for distribution of grain contributed greatly to political stability and made governance and control of territory easier.

The canal and its culture flourished during the Ming (1368-1644) and Qing (1644-1911) dynasties, but declined in the late Qing as roads, railways and ocean shipping become more important.

Shaobo remains one of the busiest waterways of the Grand Canal that once covered 3,200km and includes the Beijing-Hangzhou Grand Canal. Around 1,400km are in use today, though long stretches in the north are no longer used and a few have dried up.

Cities such as Yangzhou, Huai'an and Suzhou in Jiangsu Province are busy ports; dozens of other once-important cities are little-known today. But still some cities were born or flourished because of the canal, such as Tianjin and Cangzhou in Hebei Province.

Today the canal carries millions of tons of coal, bricks, sand, timber, diesel and other materials. Shipping bulk goods by canal is much cheaper than rail or road. The canal transports seven times more cargo than the Beijing-Shanghai Expressway.

Since it traversed different regions and cultures, the canal brought people closer together and spread ideas about religion, government, philosophy, arts, entertainment, as well as food. Some of the earliest "fusion cuisine" arose along the canal in cities such as Yangzhou.

During the Ming and Qing dynasties, Yangzhou was one of China's most important commercial and cultural centers, like Shanghai today. Yangzhou salt traders made fortunes.

The city today is a prime example of preservation that retains functioning structures and buildings along the canal as part of the city's daily life.

"It is one of the earliest cities to recognize the significance of the Grand Canal and it is one of the most important spots along canal," says Gu Feng, a renowned Grand Canal expert and historian based in Yangzhou.

Gu loves the sight of local ordinary people gathering along the canal's branch, demonstrating that the canal is naturally part of daily life, just as it was two thousand years ago.

Since the 1980s, the city started treating water pollution and planted trees along the banks and in the area. Nearby structures have been renovated. One segment of the canal is no longer used for transport, only leisure vessels. Plazas and playgrounds have been built along the banks.

Relaxing life

"I have been coming here to do exercises for at least five years," says Lin Rongyuan, a retired company manager, who wears a white silk outfit as she practices tai chi with her sword. "It's become part of my daily routine to practice with my friends here.

"When I was little, it was quite polluted with crowded houses on both sides. But look at this. Isn't it beautiful now?" she says.

Lin points at the trees, flowers and buildings rebuilt or renovated in traditional Ming- and Qing-style architecture.

After practicing for an hour, Lin and her six sword-practice friends go to a nearby restaurant to enjoy Yangzhou's famous and bountiful zao cha or breakfast tea.

In the evening she joins a dance team comprised mostly of middle-aged women. They dance for fun to remixed traditional Chinese songs when buildings are lighted and lanterns and lamps are reflected in the water.

"I'm getting used to being photographed by tourists on the boat, it's actually quite inspiring to think that I might become part of someone's memory of Yangzhou," Lin says.

When the government ended its monopoly on the salt trade in the Ming Dynasty, private traders stepped in. Yangzhou and surrounding areas were already important areas for sea salt production.

"The great business opportunities brought prosperity to the city, and naturally culture and arts were introduced through the canal, following the business," says Gu, the canal historian.

"Among all canal cities, Yangzhou is the most typical. Its rise and fall were closely related to the fortunes of the canal," he adds.

"Because of so many years of crosscurrents and cultural cross-pollination, Yangzhou itself doesn't have its own culture," Gu observes, adding that this is a positive development. "Its culture represented the most advanced Chinese wisdom. When Yangzhou can be described as a specific culture, that will be a sign of its decline."

He compares Yangzhou culture to the water in the canal: "The water can come from any part of the canal as long as it is flowing. Once you can tell which part it comes from, that means the canal has become a dead water pool."

All about the Grand Canal

World's oldest and longest manmade waterway

Originally 3,200km at peak in the Tang Dynasty (AD 618-907), including the 1,794km Beijing-Hangzhou Grand Canal

More than 1,400km in use today, including 800km navigable all year. Most of the parts still in use were expanded after 1958.

First segment dug 2,500 years ago in Yangzhou in the Wu Kingdom for military transport. Within the city, it extends 143km.

Emperor Yang of the Sui Dynasty (AD 569-618) committed more than two million men to expand the canal, to transport food from the south to the war-torn, arid north.

Stretched from the capital Beijing in the north to Hangzhou in the south, Luoyang in the east and emptied into the East China Sea near Tianjin.

Connects five major rivers: Hai, Huai, Qiantang, Yangtze and Yellow rivers. Covers most of eastern China, running through six provinces (Hebei, Shandong, Henan, Jiangsu, Anhui and Zhejiang) and the municipalities of Beijing and Tianjin.

Chinese engineers are believed to have built the world's first system of locks in AD 983, as well as feeder lakes and lateral canals.