The national land watchdog is requiring local authorities to establish permanent arable land protection zones with a total area of 104 million hectares to protect China's shrinking arable land and guarantee food security, authorities said.

Wang Lei, director of the basic farmland protection office with the Ministry of Land and Resources (MLR), told China Daily on Wednesday strict supervision will be taken after the establishment of the protection zones.

A database of arable land across the country will be set up at regional and national levels to realize real-time monitoring and the database system will show exactly where every piece of arable land is located and whether the land has been protected, Wang said.

The primary database is expected to be built in 2012, he added.

A notice released by the MLR and the Ministry of Agriculture on Monday said the protection zones will be drawn on the basis of the second national land survey, and related map and graphics for the zones will be made in the country's arable land database.

Since 2008, the MLR has monitored the land protection situation across the country.

The 104 million hectares of arable land will be guaranteed through stopping land occupation and upgrading ordinary land into good-quality land, he added.

He said except key national projects, arable land cannot be occupied for other uses, and the land occupied by key projects must be replaced with the same amount of new arable land.

He added that in addition to stopping land occupation, local authorities, organizations and individuals are encouraged to upgrade ordinary land into good-quality arable land.

Although strict land protection measures have been taken for the past three decades, the country's quick industrialization, urbanization and agricultural modernization are posing dramatic challenges to land supply.

Arable land across China dropped dramatically from 130 million hectares in 1996 to about 122 million hectares in 2008 due to rapid urbanization and natural disasters, figures from the National Bureau of Statistics show.

Illegal land-use cases were still rampant in 2010, involving 27,866 hectares of land, 1.1 percent higher than 2009, Li Jianqin, director of the law enforcement and supervision department of the MLR said in a press conference in early January.

About 10,933 hectares of the total illegally used land in 2010 were arable land, Li added.

Since 2000, China has used satellites to monitor the land-use situation in 66 cities of 25 provinces and the range has increased to a total of 2,895 regions, cities and counties across the country since 2009.

The MLR will release illegal land-use cases every quarter and release an annual illegal land-using profile based on satellite images every year.