Getting enough water is a major struggle in Darfur

Some 1,000 wells will be drilled in the region, with the agreement of Sudan's government, the Boston University researchers say.

Analysts say competition for resources between Darfur's Arab nomads and black African farmers is behind the conflict.

More than 200,000 Darfuris have died and 2m fled their homes since 2003.

"Much of the unrest in Darfur and the misery is due to water shortages," said geologist Farouk El-Baz, director of the Boston University Center for Remote Sensing, according to the AP news agency.

"Access to fresh water is essential for refugee survival, will help the peace process, and provides the necessary resources for the much needed economic development in Darfur," he said.

'Significant'

The team used radar data to find the ancient lake, which was 30,750 km2 - the size of Lake Erie in North America - the 10th largest lake in the world.

A similar discovery was made in Sudan's neighbour Egypt, where wells have been used to irrigate 150,000 acres of farmland, the researchers say.

"The root cause of the conflict is resources - drought and desertification in North Darfur."

He says this led the Arab nomads to move into South Darfur, where they came into conflict with black African farmers.

He also said that it has long been known there was water in the area but the government had not paid for it to be exploited.

French researcher Alain Gachet has also been using satellite images to look for new water resources in Darfur.

Last month, the UN Environmental Programme (Unep) said there was little prospect of peace in Darfur unless the issues of environmental destruction were addressed.

It said deserts had increased by an average of 100 km in the last 40 years, while almost 12% of forest cover had been lost in 15 years.

Secretary-General Ban Ki-moon said climate change was partly to blame for the conflict in Darfur in an editorial for US newspaper The Washington Post in June.