An ancient wooden map discovered by Chinese archaeologists in northwest China's Gansu Province has been confirmed as the country's oldest one at more than 2,200 years.

The map was drawn on four pine plates, 23 cm long, 17 cm wide and 1.5 cm thick each, and includes a drawing of Guixian County of the Qin Kingdom, one of the seven major principalities in the era of the Warring States (475-221BC).

The map, believed to have been completed in 239BC, is more than 1,300 years older than the Hua Yi Tu and Yu Ji Tu, both unearthed in the Forest of Steles in Xi'an, capital of northwest China's Shaanxi Province.

It is 300 years older than the map of Western Han (206BC-24AD), excavated from Mawangdui in central China's Hunan Province in 1973, according to the State Bureau of Surveying and Mapping.

He Shuangquan, a research fellow with the Gansu Provincial Archaeological Research Institute, has made an in-depth study of the map and confirmed its drawing time to be 239BC.

This map provided material evidence of the developed cartology of ancient China and was a precious artefact in the study of China's map-drawing technologies, said Li Wanru, a research fellow with the ancient maps laboratory of the Natural Science Research Institute under the Chinese Academy of Sciences.

Li agreed with researcher He's viewpoint that the map was the oldest among the existing maps in China.

The map of Guixian was unearthed from tombs of the Qin Kingdom at Fangmatan in Tianshui City of Gansu Province in 1986 and was listed as a national treasure in 1994.

Located in the central Qinling Mountains, Fangmatan had fertile water and soil in ancient times. Textual research shows that more than 100 Qin tombs were built on a slope in this section of the Qinling Mountains, distributed in a fan shape. All the tombs were well preserved, said archaeologists.

Archaeologists with the Gansu Provincial Archaeological Research Institute excavated 13 Qin tombs and one tomb of the Western Han at Fangmatan in 1986, unearthing over 400 relics including the map of Guixian County.

Researcher He said that the map, drawn in black on four pine wood plates of almost the same size, had clear and complete graphics depicting the administrative division, a general picture of local geography and the economic situation in Guixian County in the Warring States era.

Eighty-two places are marked with placenames, locations of rivers, mountains and forested areas on the map. What is more surprising is that the map marks the location of Wei Shui, now known as the Weihe River, and many canyons in the area.

The location of the Weihe River marked on the map agrees with the record in the Waterways Classic, a book by an unknown author of the Three Kingdoms period (220-280AD) giving a brief account of the country's 137 major waterways. Forested areas marked on the map also tallies with the distribution of various plants and the natural environment in the area today.

Unlike modern maps, placenames on these maps were written within big or small square frames, while the names of rivers, roads, major mountains, water systems and forested areas were marked directly with Chinese characters. The distances of some roadways were also marked clearly on the map.

Experts said that graphics, symbols, scales, locations, longitude and latitude are key elements of a map. The map of Guixian County has all these elements except longitude and latitude, according to historians.

(Xinhua News Agency April 30, 2002)