Lanzhou
Lanzhou is the capital and largest city of Gansu province in northwestern China. Located on the banks of the Yellow River, it is a key regional transportation hub, connecting areas further west by rail to the eastern half of the country. Historically, it has been a major link on the Northern Silk Road and it stands to become a major hub on the New Eurasian Land Bridge. The city is also a center for heavy industry and petrochemical industry.
Lanzhou is the geographical center of China’s land territory, and the third largest city in Northwest China after Xi'an and Ürümqi. Lanzhou is also an important center for scientific research and education in Northwestern China after Xi'an. The city is one of the top 50 major cities in the world by scientific research output as tracked by the Nature Index. It hosts several research institutions, including, Lanzhou University, Northwest Normal University, Lanzhou University of Technology, Gansu Agricultural University, Gansu University of Chinese Medicine, and Lanzhou Jiaotong University.
History
Originally in the territory of the ancient Western Qiangs, Lanzhou became part of the territory of the State of Qin in the 6th century BC.In 81 BC, under the Han dynasty, it was taken from the Huns' Huandi Chanyu and made the seat of Jincheng commandery, and later of the Jincheng county, later renamed Yunwu. From at least the first millennium BC it was a major link on the ancient Northern Silk Road, and also an important historic Yellow River crossing site. To protect the city, the Great Wall of China was extended as far as Yumen. Parts of the Great Wall still exist within the built-up area.
After the fall of the Han dynasty, Lanzhou became the capital of a succession of tribal states. In the 4th century it was briefly the capital of the independent state of Liang. The Northern Wei dynasty reestablished Jincheng commandery, renaming the county Jincheng. Mixed with different cultural heritages, the area at present-day Gansu province, from the 5th to the 11th century, became a center for Buddhist study. Under the Sui dynasty the city became the seat of Lanzhou prefecture for the first time, retaining this name under the Tang dynasty. In 763 the area was overrun by the Tibetan Empire and in 843 was conquered by the Tang. Later it fell into the hands of the Western Xia dynasty and was subsequently absorbed by the Song dynasty in 1081. The name Lanzhou was reestablished, and the county renamed Lanzhuan.
After 1127 it fell into the hands of the Jin dynasty, and after 1235 it came into the possession of the Mongol Empire.
Under the Ming dynasty the prefecture was demoted to a county and placed under the administration of Lintao superior prefecture, but in 1477 Lanzhou was reestablished as a political unit.
The city acquired its current name in 1656, during the Qing dynasty. When Gansu was made a separate province in 1666, Lanzhou became its capital.
In 1739 the seat of Lintao was transferred to Lanzhou, which was later made a superior prefecture called Lanzhou.
Lanzhou was badly damaged during the Dungan revolt in 1864–1875. In the 1920s and 1930s it became a center of Soviet influence in northwestern China.
File:Shengyun_and_Mannerheim_in_Lanzhou,_1908.jpg|thumb|Viceroy of Shaan-Gan and Baron C. G. E. Mannerheim in Lanzhou, 1908
Second Sino-Japanese War-World War II
During the Second Sino-Japanese War Lanzhou, linked with Xi'an by highway in 1935, became the terminus of the Chinese–Soviet highway, used as a route for Soviet supplies destined for the Xi'an area. This highway remained the primary traffic route of northwestern China until the completion of the railway from Lanzhou to Ürümqi, Xinjiang.The Battle of Lanzhou
Lanzhou's old Donggang Airport, located near the city centre, was the primary entry point for combat aircraft provided to China under the Sino-Soviet Non-Aggression Pact, and along with other targets around Lanzhou, including civilian centers, were heavily bombed by the Imperial Japanese Army Air Force and Navy Air Force. Many air battles were fought between the Chinese Air Force and the Imperial Japanese air forces over Lanzhou and surrounding regions from 1937 to 1945, particularly from 1938 to 1941 when the influx of Soviet war materials formed the primary support in China's War of Resistance against the Imperial Japanese invasion. Instances of major air-battles include an IJAAF raid consisting of 30 BR.20 and Ki-21 bombers against civilian targets in Lanzhou on 20 February 1939; 17th PS, 5th PG commander Capt. Cen Zeliu and his deputy commander Capt. Ma Guolian, a Canadian-Chinese volunteer for the Chinese Air Force, shot down the first two bombers in the battle, followed by two more downed as Capt. Cen led another attack on the third formation. They would be joined by pilots of the Soviet Volunteer Group led by Nikolay Garilov and the 15th PS led by Li Debiao, who would all shoot down five more of the Japanese bombers; the northern Chinese air-raid early-warning net headquarters in Xi'an observed 21 of the original 30 IJAAF bombers returning from Lanzhou.As the Imperial Japanese forces were preparing for Operation Z against the United States and other allies in Southeast Asia and the Pacific by mid-1941, the IJANF were busy training new aircrews in live combat action across China for the upcoming war in the Pacific; on 22 May 1941, Lt. Gao Youxin of the 21st PS, 4th PG engaged an IJNAF raid on Lanzhou in an I-16 fighter aircraft, while avoiding confrontation against the Zero fighters, he shot down a Mitsubishi G3M bomber north of Lanzhou. On the ground, the KMT Muslim Generals Ma Hongkui and Ma Bufang protected Lanzhou with their cavalry troops, putting up such resistance that the Japanese never captured Lanzhou.
Geography
At above sea level, Lanzhou lies in China's northwest geographical center. The metropolitan area covers more than of urbanisation along the southern banks of the Yellow River, which flows through from west to east. The Qilian Ranges, Mt. Pingliang, and Mt. Kongtong are located on the south and north sides of the city.Lanzhou is situated on the upper reaches of the Yellow River where it emerges from the mountains and has been a center since early times, being at the southern end of the route leading via the Hexi Corridor across Central Asia. It commands the approaches to the ancient capital area of Chang'an in Shaanxi province from both the west and the northwest, as well as the area of Qinghai Lake via the upper waters of the Yellow River and its tributaries.
Climate
Lanzhou is situated in the temperate zone and has a semi-arid climate with hot summers and cold and very dry winters. In the urban core, based on 1971-2000 normals, the monthly 24-hour average temperature ranges from in January to in July. The mean annual temperature is, while annual rainfall is, almost all of which falls from May to October. The winters are so dry that snowfall is sometimes restricted to fall and spring. With monthly percent possible sunshine ranging from 47 percent in September to 57 percent in April, sunshine is generous but not abundant, as the city receives 2,350 hours of bright sunshine annually.Environmental problems
The city is located in a narrow and curved river valley with surrounding mountains causing it to be hemmed in blocking a free flow of air. According to the National Environmental Analysis released by Tsinghua University and The Asian Development Bank in January 2013, Lanzhou was among the ten most air-polluted cities in the world. Air quality reportedly was so poor that at times one could not see Lanshan, the mountain rising up along the south side of the city. Lanzhou is also the home of many factories, including some involved in petroleum processing, and suffers from large dust storms kicked up from the Gobi Desert, especially in the winter and spring. In 2011, using Chinese statistics, the World Health Organization reported that Lanzhou had the worst air quality among eleven western Chinese cities. Its annual mean PM10 μg/m3 of 150 is 7 times the safe level established by the World Health Organization. It was worse than Beijing with its reading of 121.Since then, authorities have taken measures to improve air quality, which have largely been successful. "Thirteen polluting enterprises with excessive capacity have been closed, more than 200 highly polluting enterprises were suspended in winter, and 78 industrial enterprises have moved to an industrial park outside the city." In 2015 it was awarded China's climate progress title. As a city once unable to be spotted from satellites, Lanzhou has taken various measures to combat air pollution in recent years, having reduced its Air Pollution Index at the fastest speed across China. According to the 2018 WHO database, of 2700 towns listed, Lanzhou has the 158th highest level of PM 2.5 pollution, with an average of 54 micrograms per cubic meter. The large particle PM10 remains high, at 132 micrograms per cubic meter, in part as a result of sand storms.
The reach of the Yellow River at Lanzhou carries a high load of silt, giving the river its characteristic muddy appearance; however water quality in this reach is better than the "fetid outflow that barely passes for water two hours downstream". In recent years, several specimens of the endangered Chinese giant salamander have been found in and near the Yellow River in Lanzhou.
On April 11, 2014, Lanzhou officials advised residents not to drink tap water, because benzene levels were 20 times the national limit of 10 micrograms per liter. The city water supply suspected industrial chemical production to be the culprit, similar to what happened in the 2005 Jilin chemical plant explosions.
A brucellosis outbreak infecting humans took place in Lanzhou in 2020 after the Lanzhou Biopharmaceutical Plant involved in vaccine production accidentally pumped out the bacteria into the atmosphere in exhaust air, due to use of expired desinfectant, and affecting over 3,000 people.