Lake Salt – Vital Ingredient in Chinese History
Salt obtained from lakes is one of the earliest types of table salt used by man. Lake salt has greatly influenced the development of the Chinse civilization and features prominently throughout Chinese history. The production of lake salt requires salt lakes and China is abundant in them, with over 1500 such lakes within the country’s borders, primarily in the four western regions of Tibet, Qinghai, Xinjiang and Inner Mongolia. Many they may be, but each lake is different, as is its story.
Standing at the banks of Lop Nor, you may feel that winter has come. The “snow piles” in the photo are actually mounds of salt crystals. Photo/ Fan Shucai
A salt lake is a lake with concentration of salts in its water exceeding 3.5%. Lake salt is the salt that is mined directly from these lakes or extracted by solar evaporation from saline lake water in salt pans. Lake salt separates and crystallizes naturally by the action of wind and sunlight and so it became part of the diet of the ancient people, while the artificial extraction of salt by evaporating the water from lake brine is one of the earliest methods of salt production.
In modern Chinese, in addition for the character meaning “salt” (盐 pronounced yan), there is one which can be translated as “earth containing salt” or “brine” - 卤 (pronounced lu), but in ancient times the two meant the same thing – salt. However, lu appeared earlier than yan, and if you refer to “Shouwenjiezi”, a classic Chinese dictionary from the second century AD, it describes lu as naturally made salt, and yan as salt which has been processed by man. Joseph Needham (1900-1995), the celebrated British sinologist and expert in the history of Chinese technology, claimed that the shape of the character 卤 inscribed on Shang Dynasty oracle bones, is the representation of a man-made salt pan seen from above.
Hedong Lake in Yuncheng, Shanxi, is the oldest salt lake in China, for it has been producing salt for over 4000 years. Apart from its age, it is also a large lake, with an area covering more than 130 square kilometers.
In winter, you may see an amazing landscape, called “mirabilite rime” near Hedong Lake. Crystallized mirabilite in needle-liked shapes coagulate, and grow in clusters, forming “crystal bushes.” Photo/ Xue Jun
There are more than 1500 salt lakes in China, and most of these are found in basins between mountain ranges, for example the Qaidam Basin and the Tarim Basin. Water flows into these low-lying basins, but cannot find its way out, therefore accumulating and forming a lake to which salts are continuously transferred. Most salt lakes are situated in areas with arid or semi-arid climate, the evaporation rates here exceed the rates of precipitation, and so the salt content in lake water is continuously rising, reaching saturation and even super-saturation levels, so much so that deposits of salt are formed both on the lake bottom and on the shores.
Hedong Salt Lake
The most famous salt lake in Chinese history, and the one with the longest recorded history, is undoubtedly Hedong Lake.
Qian Mu (1895-1990), a great Chinese educator and historian says in his “Introduction to Chinese Culture History”: “The Hedong Lake, which lies in the vicinity of Xiexian County (today’s Xiezhou in Shanxi Province), has been fought over by many clans and tribes of ancient China, and to arrive at the shores of this lake, triumphantly, was a mark of a making of any leader of these ancient Chinese tribes.”huangdi, the legendary Yellow Emperor, the founder of Chinese civilization, also strove for the control of this lak. He fought his enemies, Yandi and Chi You, in two great battles – of Zhuolu and Banquan. Victories in these battles allowed The Yellow Emperor to firmly secure Hedong Lake and its vital supply of edible salt for the Central Plains, and then to ascend to become the leader of all Chinese clans and tribes, and the most venerated supreme ancestor of the entire Chinese race.
A salt lake is a lake with a concentration of salts in its water exceeding 3.5%.There are currently more than 1500 salt lakes in China and according to Zheng Mianping, the famous geologist and academician, they can be divided into four zones: A—salt Lake Zone on the Qinghai-tibet Plateau: With an average elevation of 4000 meters, this area has salt lakes with complicated chemical components. For example, Qarhan Lake is rich in potassium and magnesium. B—salt Lake Zone in Northwestern China: The elevation of this area ranges from 500 to 1500 meters, much lower than the Qinghai-tibet Plateau. Most salt lakes here are small ones, but there are also large ones like the famous Lop Nor. The extreme arid climate gives this region rich resources of nitrate. C—salt Lake Zone in Northeastern China: Including the Ordos Plateau, the Inner Mongolia Plateau and the Hulunbuir Basin, this zone has some of the smallest salt lakes in China, yet each of them is rich in mirabilite, trona and rock salt. D—scattered Salt Lake Zones in Eastern China: Situated in a humid area with an annual precipitation of over 500 mm, the salt lakes here are relatively poor in mineral resources and most of them are small ones, just like those in the Northeastern China Zone.
The earliest method of obtaining the salt from Hedong Lake was done by simply scooping it up – salt crystals formed naturally under the fierce sun and people just collected them. The production relied entirely on natural forces - Hedong Lake is one of the hottest places in summer in the whole of northern China, with temperatures rising as high as 42.6 degrees Celsius. Sunshine is plentiful and the annual precipitation rates are just 520mm, whereas evaporation rates reach 2300mm.
This “scooped – up salt” as people called it, was basically natural formed salt crystals, and they contained impurities, such as magnesium sulphate, which often gave it a bitter taste, and for this reason the salt from Hedong was also known as “bitter salt.”
Qarhan Lake is known for its rich sylvite resources. But a common tourist might be more interested in the incredible salt karst landforms here; for example, the salt stalactites or “salt flowers” shown in the photo. Photo/ Yao Zhengwu
During the Eastern Han Dynasty (25 -220 AD) a different method started to be used – construction of salt beds or pans, which were then flooded with water using specially constructed channels and left to evaporate under the sun, leaving crystallized salt. As at that time this method was still in its infancy, the salt-laden water was not filtered before entering the pans, and the crystals, formed on the top of the soil, still retained their bitter taste.
By the time of the Tang Dynasty the salt workers improved the salt pan method by introducing the use of freshwater – the fresh water is colder than saline water,and this difference in temperature makes magnesium and sodium sulphate and other impurities to precipitate and form a layer on which salt crystals are then formed. Salt produced by this method no longer tastes bitter and also the time of crystal formation is greatly reduced, down to five or six days; representing a mile stone improvement in the development of salt production.
Hedong Lake retained its importance in Chinese salt production for the following thousand years, and at its peak the salt taxes it generated amounted to one eights of the state revenue. During the middle of the Qing Dynasty, the concentration of brine water declined, and so did the production capacity of Hedong, and, as modern technology reduced the costs of the production and transportation of sea salt, Hedong gradually lost its dominant position.
Jilantai Lake is situated in Alxa Plateau in the western part of Inner Mongolia and its salt works can be traced all the way back to the Tang Dynasty (618 – 907). In the year 850AD salt production was placed under central Imperial administration due to the excellent quality and yield of salt. In the beginning of the 18th century the salt extracted here was transported and sold in the central regions of China and the production attained large scale.
Da Qaidam Lake covers an area of 240 square kilometers, but the area of its brine water occupies only 36 square kilometers. In China, Da Qaidam is the most famous salt lake that produces borate. Photo/ Chen Shenggui
Jilantai Lake sits on the alluvial and diluvial planes between Helan Mountain and Bayanwula Mountain, on the western edge of Wulanbuhe Desert. The climate here is classic arid continental with little rainfall and frequent sand storms. The ecosystem here is very fragile, and the landscape is that of a typical desert salt lake – the vegetation consists of small shrubs,the banks are covered by dry salt flats, and there are salt ridges and sand dunes everywhere.
The desertification and sandstorms had brought this lake to the brink of a catastrophe. Fortunately the problem was brought under control by years of supplying the lake with water and anti-desertification measures such as stabilization work by planting aquatic and salt-tolerant plants.
Jilantai might be out of danger, but it has acted as a warning to us, raising questions of how should salt lakes be exploited in a healthy, sustainable manner. Our knowledge and exploitation of salt lakes is no longer limited to extracting table salt, the industry of mining deep under lake beds has already been launched, and the biological resources of salt lakes, such as brine shrimp, have been attracting more and more attention. Let’s just hope that China, with its vast resources of salt lakes, can now
avoid the past experience of over exploitation which has left in its wake dried up, destroyed lakes; and, instead, implement a sustainable, healthy development policy.
Apart from mineral resources, salt lakes also provide several biological resources, such as brine shrimp, a small aquatic crustacean living in brine water. People use brine shrimp to feed commercially harvested aquatic species, for example, crab, fish and shrimp. Photo/ Ma Hongjie Chaka Salt Lake
Chaka Salt Lake is situated at the most eastern end of Qaidam Basin, within the boundaries of Wulan County of Qinghai Province. Salt extraction started here during the time of the Western Han Dynasty (202BC – 25 AD) by the Qiang people, and organized production was set up in 1908. However, archaeological finds in 2010
revealed evidence of people’s long- term habitation and activity at Chaka Lake from over 3,000 years ago, and history of salt extraction at the lake might go back further in time still.
Seen from above, Eji Nor, a salt lake situated in the north of the Xilin Gol Steppe, has distinctive water in red and pink colors. According to current research, Eji Nor’s unique water colors derive from its ever changing water depth, sunlight and microbes living within it. Photo/ Yang Zijian
When you come to the lake you approach a world of pristine white, there are salt mounds, rising like mountains, on both sides of the lake, and the further you look into the distance the more intense the whiteness of the lake becomes. This white landscape seems infinite and you can’t help but feel that you have somehow been transported to the North Pole. The perfectly flat, snow-white land surface reflects the blinding sunlight like a mirror. A train, salt dredging boats and a conveyor belt, however, remind us that we are in the middle of a modern salt mining operation. A locomotive pulling a line of wagons equipped with load-carrying bins runs along a shiny narrow track, returning from the center of the lake. Two men overturn the endless procession
of bins, emptying out the salt, which then goes onto the conveyor belt to be processed and filtered. Elsewhere, a salt dredger sails along a canal to the center of the lake. The dredger choses a good area to work, and then mechanically breaks up the salt layer, pumping the salt suspension on board, which is then transported, via a pipeline from the stern of the boat, to the shore or mobile filtering station s on the lake where the water is filtered out. After this process is complete, the solid salt is transported out by train.
Qarhan Salt Lake
This is China’s largest salt lake, 168 kilometers long, between 20 and 40 kilometers wide, with the total area of 5856 square kilometers. Most of its surface is now taken up by dry salt flats, with ten saline lakes on the periphery, as well as several seasonal saline lakes, and the actual water surface is no more than 10% of the total area.
The Lop Nor in Northwestern China is another salt lake famous for its sylvite resources and it is reported that Lop Nor may even become the largest production base of sylvite in China. Perhaps in the future, the Lop Nor and its surrounding areas will become the “Salt Lake City” of China. Photo/ Gao Zonglin
Once in the past, the Lop Nor dried up and its lakebed was exposed under the sun. In2001, brine water rich in sylvite was discovered in this region and gushing brine water brought back the amazing azure water of Lop Nor. Photo/ Fan Shucai
You cannot say enough about the landscape here – because of the covering layer of salt, even though this is supposed to be a lake, you can’t actually see any water. This place looks like a recently plowed piece of fertile virgin land - the jade green saline
lakes are separated by the precipitated, ornamental ridges of salt. The covering layer of salt is between 15 and 18 meters thick and formed astonishing natural bridges, and then there also the salt karst formations.
These salt karst formations of Qarhan Lake are a product of the arid climate of the plateau, and they are formed differently from the limestone karst of humid climate. The key for the formation of salt karst landforms is the water layer on the margins of the lake and the pressure it exerts in the water below.
The “salt flowers” in the photo were found in Lop Nor. Due to its long, conical shape, this structure is also called a “salt fang” or a “salt coral”. Photo/ Gao Zonglin & Wang Jianzheng
In an ancient salt lake near Wensu County, Xinjiang, you can see the distinctive salt karst landforms as in this photo. Mixed with mud, sand and other impurities, these salt crystals appear brown or red, rather than white. If enlarged, their keen edges appear as continuous “blade mountains.” Photo/ Gao Zonglin
“I rode for three days and there was nothing but salt under the hooves of my horse” – the local people have been proud of the abundance of their salt resources. The name Qaidam means “salt marsh” in Mongolian, and 33 saline lakes of various sizes, six
dried up salt lakes are found here. The total area covered by salt reaches 17000 square kilometers, and the total volume of saline water approaches 40 billion cubic meters.
Zhabuye Salt Lake
Apart from the Qinghai Province where Qaidam Basin is located, Tibet is another area where salt lakes are highly developted. There are more than 340 such lakes here, mostly found in the northern part of Tibet. There are many large lakes but also almost half of these lakes have special characteristics. Comparatively speaking, the proportion of minerals contained in Tibetan lake salt is higher than that in Qinghai lakes, containing a greater amount of rare elements, and these special salt lakes of Northern Tibet contain great potential for exploitation.
Manas Lake, a large salt lake in the hinterland of the Junggar Basin, covers nearly 650 square kilometers. To explore the rich mineral resources stored here, people built several straight water channels.seen from above, the Manas looks like a giant carpet with white string decorations (which are the salt piles). Photo/ Gao Zonglin
In Zhongba County in Shigatse, Tibet, there is a salt lake called Zhabuye. At the beginning of 1990s, Zheng Mianping, an academician of the Chinese Academy of Sciences, discovered, on a small island in the middle of this lake, the world’s only naturally occurring lithium salt - lithium carbonate. Known as Zhabuye Stone, it has since attracted the attention of Chinese as well as international scientists, and further research on the lake continued to yield surprising discoveries.
Shadows of towering salt mounds are reflected in the mirror-like water of Urho Lake in Xinjiang, giving us an atmosphere of peace. Urho Lake is also one of the largest salt lakes in China. Photo/ Gao Zonglin
China is abundant in salt lakes, but only a small number of them are currently commercially exploited, but they contain a great potential, in terms of mineral and biological wealth, to boost the social and economic growth in the West of China which still lags behind in development.
The exploitation of the economic potential of salt lakes, however, must be sustainable, relying on a scientific approach, prioritizing both the development of the western regions, as well as the preservation of the natural environment in equal measure.
Althoughwith an area of 113 square kilometers, Balikun Lake in Xinjiang is not a large lake. Balikun has its own distinctive landscape— large “rocks” of saline minerals scattered around the lake. As an ancient lake, Balikun underwent long periods of repeating evaporations; hence, you can see mineral rocks—namely the traces of diagenesis—everywhere. Photo/ Fan Shucai