Gyokumon

A county-level city in the northwest of Gansu Province, China. It is home to the Yumen oil field and is one of the petroleum industrial bases in the northwest region. It belongs to the Jiuquan prefecture-level city. It has a permanent population of 159,792 (2010). A branch line is drawn into the city from the Lanxin line. It is located at the northwest end of the Hexi Corridor, and has been the entrance from the Chinese world to the Western Regions since ancient times. Jiayuguan Pass, the western end of the Great Wall, is to the east of this pass. However, the remains of the Yumen Pass (meaning the entrance where jade from the Western Regions was brought) built during the Han Dynasty are believed to be located in Xiaofanpancheng, northwest of the current city of Dunhuang, and it is said that after the pass was abandoned, the garrison was moved to the rear and it was established as a county here. There was a long period afterwards when the area was under the control of foreign tribes from the north, and although Yumen County (now Yumen Town) was established there again during the Qing Dynasty, it was not a particularly developed city.

However, in modern times, the city has grown rapidly as the oil fields have been developed. The existence of oil in the area has been known since the Northern and Southern Dynasties period, but in 1938 the Kuomintang established the Gansu Oilfield Bureau, constructed oil extraction facilities and began development. After the founding of the People's Republic of China, development continued, and the area was a representative oil field in the early days of Chinese oil development. In 1955 the oilfield area was made into a city, and later Yumen County was annexed as well. However, since the Yumen branch of China National Petroleum Corporation (PetroChina) moved to Suzhou District, Jiuquan City in 2001, the oil-related industry has been shrinking.

The area around the former county is an oasis formed by the Soroku River, and oasis agriculture is carried out.

[Motohide Akiyama, Editorial Department, June 20, 2017]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

中国、甘粛(かんしゅく)省北西部の県級市。玉門油田があり西北地区の石油工業基地の一つである。酒泉(しゅせん)地級市に属する。常住人口15万9792（2010）。蘭新(らんしん)線より支線が引き込まれている。河西(かせい)回廊の北西端に位置し、古くから中国世界から西域(せいいき)への入口であった。万里の長城の西端である嘉峪関(かよくかん)はこの東にある。ただし漢代に置かれた玉門関（西域の玉がもたらされる入口という意味）は、いまの敦煌(とんこう)市の北西、小方盤城(しょうほうばんじょう)がその遺跡とされ、関が廃されたのち、守備隊が後方に移されて県とされたのがここであるという。その後、北方異民族の支配下にある期間も長く、清(しん)代に玉門県（いまの玉門鎮）がふたたび置かれていたものの、とくに発展した都市ではなかった。

　しかし、近代に油田が開発されるとともに都市も急速に発達した。付近の石油の存在は古く南北朝時代から知られていたが、1938年国民党は甘粛油田局を設けて採油設備を建設し開発を始めた。中華人民共和国成立後、さらに開発が進められ、中国石油開発の初期における代表的油田であった。1955年、油田地区を市とし、のちに玉門県をも併合した。しかし、2001年に中国石油天然気（ペトロチャイナ）の玉門支社が酒泉市粛州(しゅくしゅう)区に移って以降、石油関連産業は縮小している。

　旧県付近は疏勒河(そろくが)の形成するオアシスで、オアシス農業が行われている。

［秋山元秀・編集部　2017年6月20日］

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