BEIJING - China's Yellow River has gone digital, part of a government project in which scientists use sophisticated computer models to study and 'tame' the country's second-longest river.

Besides digitised models, the scientists also use huge physical models built to simulate the river's erratic behaviour.

Known as China's Sorrow, the 5,464-km river has been blamed for bringing untold suffering to the people living next to it each time it bursts its banks.

Records show that the river has burst its banks more than 1,500 times and changed course 26 times in the past 2,500 years.

Hundreds of thousands of lives have been lost.

The main focus of the digital Yellow River project, therefore, is to use high-tech means to better prevent flooding, forecast rainfall and monitor rising water levels, water crests and sources of pollution.

According to Mr Cheng Xiaotao, director of the Department of Water Hazard Research at the China Institute of Water Resources and Hydropower Research, the computer models use remote sensors, GIS (geographic information system), GPS (global positioning system), and other technologies to gather information about the river.

Mr Cheng says data collection remains the most difficult part of building computer models.

'Sediment collects and shifts so quickly that river bed levels can fluctuate by as much as two to three metres between sections,' he explains.

The river historically alternates between flooding and drought.

It runs for 617 km through eastern Shandong province and some spots are prone to dry up periodically.

In recent years, the situation has worsened, with the dry river bed stretching hundreds of kilometres inland to Henan province as a result of excessive use by industries and households along its upper and middle reaches.

Each time the river dries up, the State Council issues orders to release water from upstream reservoirs like Liujiaxia and Longyangxia.

But such hasty measures disrupt power generation and water usage along the upper and middle reaches.

Mr Cheng said that China has been making computer models of the Yellow River since the early 1990s, but the current project brings together all the efforts undertaken so far.

He estimates it will take another 10 years before the software can achieve a high degree of reliability.

The software will be particularly useful in determining water-use rights and water prices along the entire length of the river.

'Currently, there is no yardstick by which we can measure who is over-using water because rainfall and water levels change every year.

'With digital Yellow River, we will have developed a model for the entire Yellow River,' says Mr Cheng.

Although the project is underwritten by the central government with aid from the Asian Development Bank, project leaders are still uncertain about overall costs, he said.

But, as digital Yellow River gradually matures as a reliable technology, it can be applied to other major river systems in China and abroad.

An Internet website has been set up to promote the project around the world.