Authorities responsible for areas along major flood-prone rivers, particularly the rain-swollen Yangtze, have been urged to prepare for the year's worst floods as China enters its major rainy season this month.

Deng Jian, deputy director of the Office of the State Flood-Control and Drought-Relief Headquarters, told China Daily: "It is high time for water levels in the Yangtze and other major rivers to rise as more rain is predicted for this month, the beginning of the major flood season throughout China."

China's big rivers - including the Yangtze, Huaihe and Yellow - will face rising water levels, which might lead to flooding with more rains in the next few weeks, Deng said.

In Central and East China, major floods are likely to occur along the middle and lower reaches of the Yangtze, one of China's key flood-prone areas.

But Deng refused to predict how strong the floods might be. He said: "It will depend on the intensity of rain falling on the river and the consequent run-off formed in the weeks ahead."

The season's rain belt is moving quickly. "The belt was in the Huaihe River valley only a few days ago and is now in the skies over the middle and lower reaches of the Yangtze River," said Deng.

By yesterday, rainfall had pushed up water levels to above the warning levels at Chenglingji and Hukou, outlets of the Dongting and Poyang lakes leading to the Yangtze.

Although torrential rain has caused many local creeks and rivers to overflow since early June, the rain - much of which fell in drought-prone regions - has not increased the run-off on the main parts of China's major rivers.

Deng said this is why China's major rivers have remained "basically stable" without flooding so far this week except for the Huaihe and Pearl rivers.

Flash-flood waters have receded and passed downstream without causing heavy damage in the Huaihe, China's third-longest river, and in the Xijiang, a tributary of the Pearl River in South China.

To date, water levels are below their alarm levels on most of the main sections of the Yangtze, Yellow, Huaihe, Songhua, Liaohe and Haihe rivers.

But more than 500 people have been killed in flooding since the start of June. The floods have also caused 26 billion yuan (US$3.1 billion) in damage in 18 provinces.

Deng admitted: "China has suffered heavy damage from the flooding on some local rivers due to torrential rain."

He said the most significant factor in the heavy flooding was that storms took the rainfall to more than 600 millimetres in a few areas.

The rain that fell between June 7 and 11 covered two-thirds of China's territory and triggered the worst floods ever recorded in many local rivers' history, including the Ziwu and Xunhe in Northwest China's Shaanxi Province and the Jinxi River in Fujian Province.

The worst-hit province was Shaanxi, where 151 people were killed and 300 others missing. Heavy rainfall caused torrents of water, mud and rock to tumble from the mountains in remote areas such as Foping, the hardest-hit county in the province.

Such flooding is usually particularly destructive in drought-plagued areas such as Foping. People had got used to farming in dry river beds for years and were unaware of the risk of flooding, experts said.

China still faces major difficulties in its fight against devastating floods despite its massive reinforcement of levees on major flood-prone rivers since 1998. The reinforcement aimed to increase flood-control capacity and mitigate possible damage.

Some experts have expressed concern that sections of embankment have still not been reinforced, as well as worries over the operation of some flood basins and the dependability and security of the new facilities.

But another expert at the flood-control headquarters, who declined to be named, predicted: Emergencies will not occur everywhere this year even if there is flooding like that in 1998 thanks to the large-scale reinforcement along thousands of kilometres of levees on the middle and lower reaches of the Yangtze River.

Following the consolidation of more than 3,000 kilometres of levees along the Yangtze, "major anti-flood facilities along the river are capable of withstanding flooding like that in 1954, one of the river's worst in history," the expert said.

However, the expert made it clear that this does not mean that flood control along the Yangtze, Yellow and other major rivers "has been completed once and forever."

Many things remain to be done to perfect anti-flood systems on the rivers, the expert said.

Many new water-control projects have to be tested by floods to prove they can withstand flash flooding during the rainy season, the expert said.

(China Daily July 3, 2002)