The authorities will not allow the amount of arable land in the country to shrink to less than 120 million hectares, a top land official said Monday while announcing the launch of a nationwide land-use survey.

Addressing a "National Land Day" ceremony yesterday, Land and Resources Minister Xu Shaoshi said conservative land-use would be a key part of economic development and social stability.

Xu warned that the amount of arable land was shrinking due to relentless construction and a poor land-use system.

The most recent national survey, released in October, showed that the country's arable land had dwindled to 121.8 million hectares, representing a year-on-year decline of 307,000 hectares.

Most of the lost land went to construction, natural disasters and reforestation, the ministry said.

China has less than 10 percent of the world's arable land and one-fifth of the world's population, so land-loss poses a grave threat to the country's sustainable development, Xu said.

The rapid industrialization and urbanization in recent years and the country's increasing population have all made claims on the amount of available land, he said.

"The gap between the supply of land and demand for it will continue to grow," he said.

"We must stick to the strictest possible land-management system, use land in a conservative way and firmly guard the 120 million-hectare bottom line."

Xu said the land-approval process would be tightened to force local governments to make better use of their available land and spur the disposal of land that has already been approved for use.

And next month the authorities will kick off a three-year national land-use survey.

Vice-Premier Zeng Peiyan said last week the survey would help the authorities get a clear picture of the nation's land resources and improve the land-management system.

The authorities will also set up a database to monitor land use, he said.

The authorities conducted the first such survey from 1984 to 1996, from which they developed a rough picture of the available land resources.

However, there were concerns that local officials had hid or even fabricated data during the inspection. Soaring property prices have made land sales very lucrative, and some local governments have waded into the market for extra funds.

As a result, cases of illegal land acquisition have become more frequent in recent years. They often involve local officials who have used their power to approve land deals to fill their own pockets.

To clamp down on the possibility of cheating in the forthcoming survey, Xu said, the ministry would conduct random checks and punish anyone who fabricates or hides data.