Economy

Old Salt Wells in ZigongBoiling Brine into Pure SaltSalt was once one of the major sources of revenue for China. To give an idea of how much money was generated from salt in China - after the fall of the last emperor, the Republic of China under Sun Yat-sen secured loans based upon the revenues of the Chinese Salt Administration (the government agency in charge of taxation on salt). The chief inspector of that administration stated "The best salt in China is produced from the salt wells of Sichuan". The best salt wells in Sichuan are in Ziliujing District, Zigong.The people of Zigong have been drilling in the area for Salt since before the Han Dynasty (76-88 A.D.) to extract salt from brine. Some historian estimates are that China has been active in producing salt since about 6000 BC. The brine aquifers in the area have salinity of at least 50 grams per liter. The classical method of drilling and production was the following: a drilling rig is erected and a borehole is drilled using a drilling bit and rope. Brine is extracted by dropping a long tube down the borehole. A membrane valve then captures the brine for retrieval on the surface. Once the brine is retrieved it's then piped to flat pans for boiling. In the boiling process some water and crushed yellow soybean is added. The soybean absorbs the impurities in the salt. Once boiled, a yellow layer is formed - this is scraped off leaving absolutely pure salt. The salt is a medium grain salt with different size flakes which have a very strong and unique salt taste. This salt has no additives so it does clump. Locals use grains of rice in the salt to keep the salt from clumping.Early methods of brine salt production involved digging large pits in the earth (other parts of China used the evaporation method). Later methods involved very innovative drilling and retrieval methods. An unexpected byproduct of the drilling and resulting wells was natural gas. Since natural gas didn't have the uses it does today, it was channeled into pipes and primarily used onsite to boil the brine and extract the salt. The salt Zigong produced was very rich in taste and was served to the Emperor of China as a tribute. The people of Zigong believe its taste to be superior to the popular French sea salts such as Fleur de sel.Salt production via boreholes was once prevalent in the entire Sichuan area - but for several factors (war, rebellion, taxes, wells drying up) Zigong became the center of production. Salt wells in Zigong were deeper and had better brine salinity - making for better yields in the salt extraction process. The method in which boreholes were drilled is significant. In 1835, the world's (at that time) deepest well was drilled reaching 3,300 feet (compared with a much publicised well in Pennsylvania at 69.5 feet). Wealthy families of the Sichuan city of Jingyan invented deep percussion drilling techniques used in Zigong - 400 years before the Europeans. The miners of Zigong refined the techniques of deep borehole drilling. Later, Europeans copied and further refined the percussion drilling methods - so its effects can be seen in the modern Drilling rig used for oil and water.Salt became an engine of commerce and wealth for Zigong. There were cheaper methods for salt production, as to start a borehole well cost 3,000 pieces of silver, but transportation cost into the Sichuan valley negated the cheaper production methods (as they usually involved sea water). Zigong is located in the central Chinese Sichuan province, which was a large basin, surrounded by mountains on three sides and therefore somewhat isolated. Before refrigeration was available salt was a key chemical used in preserving vegetables, meat, and fish. Because of the factors mentioned above (war, wells drying up, and a rebellion) Zigong became a significant supplier of salt to the Sichuan province up until the 1930s. In 1892, miners discovered a vein of rocksalt that feeds Zigongs aquifers. In 1946, a well was drilled with a rotary drillbit. Ancient percussion drilling methods became obsolete and most of the drilling rigs were torn down due to decay. Today, only one traditional salt well still exists, the Shenhai Well, as a tribute to the workers and industry. The Shenhai Well (Bore depth: 1,001.4 meters/4,400 feet) still operates using the older manual methods of pumping and boiling. The salt is used for pickling or canning - and makes an important ingredient to Sichuan style pickles (which are a local favorite). In the modern day, Zigong is a primary source for Natural Gas, Coal, and Inorganic Chemical Production in addition to salt.

Geography

Zigong is located in the Sichuan Basin, and has an area extension of 4,372.6 km2 (1,688.3 sq mi). Granted the recognition as one of the Historical and Cultural Cities of China by the State Council of the People's Republic of China. Zigong has long been renowned as "Salt City" for its brine extraction techniques and the attendant salt-related culture.[citation needed] In ancient China, Salt was regarded as the energy for body and valued higher even than Gold.[citation needed] Therefore, salt trading was always the most profitable business and salt merchants were the wealthiest people. Hence, Zigong had always been one of the richest cities in China until the founding of China with the introduction of new salt producing methods and advancing of technologies.[citation needed] It has had the Zigong Salt Museum since 1736.The Fuxi River, a tributary to the Yangtze River, snakes through the city's core. The area is very humid and the visibility can be reduced dramatically in the area due to ground fog. The humidity and fog of Zigong can be attributed to that it sits on what was once a vast inland sea. Changes in the environment caused the water levels to subside leaving salt, brine, and natural gas.During the summer months, the temperatures can reach as high as 40 °C (104 °F); during the winter months the temperatures hover around 15.5 °C (60 °F). The humidity hovers between 80% and 90% year round.[citation needed]Using the coordinates link, one can find aerial photographic views, satellite imagery, night views, and road maps: Coordinates: (29°20′6.60″N 104°46′25.39″E / 29.3351667°N 104.7737194°E / 29.3351667; 104.7737194)Zigong is situated south of the Sichuan basin hill country. To the east of Zigong is Luzhou and to the west of Zigong is Leshan. To Zigong's south is Yibin and to the north-east is the city of Neijiang.

Demographics

According to the 2010 Census, the prefecture-level city of Zigong has a population of 2,678,899 inhabitants less than in 2000 (the average annual population growth for the period 2000-2010 was of -1.24%). Nevertheless, the built-up (or metro) area made of 4 urban districts is still growing with 1,262,064 inhabitants (1,051,384 in 2000).

History

The area of Zigong has a long history in ancient China - with the invention and development of "Percussion Drilling rig" being one of the city's accomplishments. There are essentially two cities - that of the old and the new. The city was reached by rail in the 1950s. Several four-lane highways reach the city from other cities in the Sichuan province. The new city of Zigong has been modernizing since the late 1970s - but more rapidly since the early 1990s. The old "Salt" city is based on industry and farmland and a new "Tourism" city which caters primarily to Chinese tourists (as Zigong is better known within mainland China). Zigong is host to the Sichuan University of Science and Engineering as well as a new High Technology Zone.Zigong Dinosaur MuseumSinraptor at the Zigong Dinosaur MuseumA display at the museumIn the 1980s, vast dinosaur fossils were excavated in the Dashanpu Formation, 7 km (4.3 mi) north-east from downtown Zigong, including a dinosaur named after the township, Dashanpusaurus. Because of the unique and intact bone remains, Zigong has ever since been attracting paleontologists and dinosaur enthusiasts from around the world. In 1987, the Zigong Dinosaur Museum (自贡恐龙博物馆) was established, becoming the first specialized dinosaur museum open in Asia. Mounted specimens include Omeisaurus, Gigantspinosaurus, Yangchuanosaurus hepingensis, Huayangosaurus and Xiaosaurus.