Lánzhōu (Chinese: 兰州; Postal map spelling: Lanchow) is the capital and largest city of Gansu Province in Northwest China. A prefecture-level city, it is a key regional transportation hub, allowing areas further west to maintain railroad connections to the eastern half of the country. Lanzhou is home to 3,616,163 inhabitants at the 2010 census and 2,177,130 in the built-up area (urban) of 1,088 square kilometres (420 sq mi).
- Area: 13,300 km²
- Elevation: 1,600 m above sea level
- China’s northwest geographical center
- More than 20 square kilometres (7.7 sq mi) of urbanisation along the southern banks of the Yellow River.
- Zonary basin
- Mountains are located on the south and north sides of the city:
- The Yellow River flows through from west to east.
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 (modern Xi’an) in Shaanxi province from both the west and the northwest, as well as the area ofQinghai Lake via the upper waters of the Yellow River and its tributaries.
Further information: Environment of China
Lanzhou is situated in the temperate zone and enjoys a semi-arid climate (Köppen BSk) with hot summers and cold and dry winters. Diurnal temperature ranges tend to be somewhat large due to the high elevation and aridity. The mean annual temperature is 9.8 °C(49.6 °F), while annual rainfall is 315 millimetres (12.4 in), almost all of which falls from May to October. The winters are so dry that snow is extremely rare.
Serious Air pollution in the city means that it has some of the worst air quality of all the cities in China. According to the Blacksmith Institute, Lanzhou is one of the 30 most polluted cities in the world, with its TSP (total suspended particle)] rating 247% above that of the Gansu State recommendation. Air quality is so poor that at times one cannot see Lanshan, the mountain rising straight up along the south side of the city. At one point, a controversial suggestion was put forward to bulldoze a mountain adjacent to the city, in order to let fresh air in to the bowl where Lanzhou is situated. It was suggested on the premise that the surrounding mountains block a free flow of air in the city. The city is located in a narrow river valley with an unfortunate curve causing it to be hemmed in with no free air flow. Lanzhou is also the home of many factories, including some involved in petroleum processing, and suffers from large dust stormskicked up from the Gobi Desert, especially in the winter and spring. In 2011, using Chinese statistics, the World Health Organizationreported that Lanzhou has the worst air quality (annual mean PM10 ug/m3 of 150) among eleven western China cities, and is even worse than Beijing with its reading of 121.
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”.
Well if you really want to do it, let me teach you the ways, first you need to study the weather, then how rainfall affects the region that contributes to the Yellow river, then the surrounding mountains that affect the geography of the region, then with all the information you can devise a plan to remove any mountains, or create any irrigation, or play with the rainfall by seeding the clouds to create the ideal environment to support the climate you want, even flattening land to built your city, but it must be sustainable, just bulldozing the land will create a deep environment havoc that cannot be undone.
– Contributed by Oogle.