Dian Lake (), also known as Dianchi, Dianchi Lake, Lake Dian and Kunming Lake, is a fault lake located on the Puduhe- Xishan fault in

Kunming Kunming is the capital and largest city of the province of Yunnan in China. The political, economic, communications and cultural centre of the province, Kunming is also the seat of the provincial government. During World War II, Kunming was a Ch ...

Yunnan Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

at 24°23′–26°22′ N, 102°10′–103°40′ E. Its nickname is the "Sparkling Pearl Embedded in a Highland" (;

pinyin Hanyu Pinyin, or simply pinyin, officially the Chinese Phonetic Alphabet, is the most common romanization system for Standard Chinese. ''Hanyu'' () literally means 'Han Chinese, Han language'—that is, the Chinese language—while ''pinyin' ...

: ''Gāoyuánmíngzhū''). It is the model for the Kunming Lake in

Beijing Beijing, Chinese postal romanization, previously romanized as Peking, is the capital city of China. With more than 22 million residents, it is the world's List of national capitals by population, most populous national capital city as well as ...

Summer Palace The Summer Palace () is a vast ensemble of lakes, gardens and palaces in Beijing. It was an imperial garden during the Qing dynasty. Inside includes Longevity Hill () Kunming Lake and Seventeen Hole Bridge. It covers an expanse of , three-quar ...

. Its name is the source of

's Chinese abbreviation . Dian Lake is a shallow freshwater fault

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

. The Lake is 40 km long, running from north to south, and has an average width of 7 km with the widest point being 12.5 km. The lake is 1886 meters above sea level and has 150 km of coastline. The lake's drainage area has a monsoon-affected subtropical highland climate (

Köppen Köppen is a German surname. Notable people with the surname include: * Bernd Köppen (1951–2014), German pianist and composer * Carl Köppen (1833-1907), German military advisor in Meiji era Japan * Edlef Köppen (1893–1939), German author ...

''Cwb''), with an average annual temperature of 14.4 °C, a frost-free period of 227 days, and an annual precipitation of 1036 mm. The lake covers . The lake has an average depth of , and is divided into two parts by an artificial dike. The northern end of the lake is called Caohai (;

: ''Cáohǎi'') and has a surface area of 7.5 km² and an average depth of 2.5 meters. The southern end of the lake, comprising the majority of the lake, is called Waihai (;

: ''Wàihǎi'') and has a surface area of 292 km² and an average depth of 4.4 m. The water flows out of the lake to the west via the Pudu River ( Chinese: 普渡河;

: ''Pǔdù Hé'') which eventually joins the Yangtze River before finally reaching the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. Dian Lake is the sixth largest lake in China and the largest lake in Yunnan Province.

Etymology

The

Chinese character Chinese characters are logographs used to write the Chinese languages and others from regions historically influenced by Chinese culture. Of the four independently invented writing systems accepted by scholars, they represent the only on ...

for the lake (;

: ''Diān'') is a phonosemantic compound of the radical ("water") and the character ("real"). The character was first found in the '' Records of the Grand Historian'' as the name of the Dian Kingdom. Modern studies suggest that the character 滇 is derived from the language of the extinct ancient Bo people and means basin. The character 滇 has been used as the name of the lake since at least 109 BC, when the

Han dynasty The Han dynasty was an Dynasties of China, imperial dynasty of China (202 BC9 AD, 25–220 AD) established by Liu Bang and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–206 BC ...

established "Dianchi County" (滇池县) in the area.

History

Dian Lake was the site of the capital of the independent kingdom of the Cuan () during the first millennium AD. At that time, it was known as Kunchuan ().. During the

Three Kingdoms The Three Kingdoms of Cao Wei, Shu Han, and Eastern Wu dominated China from AD 220 to 280 following the end of the Han dynasty. This period was preceded by the Eastern Han dynasty and followed by the Jin dynasty (266–420), Western Jin dyna ...

period (220-280 CE), Dian Lake was where the forces of

Shu Han Han (; 221–263), known in historiography as Shu Han ( ) or Ji Han ( "Junior Han"), or often shortened to Shu ( zh, t=蜀, p=Shǔ; Sichuanese Pinyin: ''Su'' < Middle Chinese: *''źjowk'' < Eastern Han Chinese: *''dźok''), was a Dynasties in ...

, led by their chancellor

Zhuge Liang Zhuge Liang () (181September or October 234), also commonly known by his courtesy name Kongming, was a Chinese statesman, strategist, and inventor who lived through the End of the Han dynasty, end of the Eastern Han dynasty ( 184–220) and t ...

, visited in triumph after quelling a rebellion by the Nanman tribes of the south. Between 1958 and 1970, under the CCP's agriculture strategy of "Taking grain as the key link", approximately 54 square kilometers of Dian Lake marshland were reclaimed to expand industry and agriculture in the Kunming basin. On December 28, 1969, a rally for "reclaiming land from the sea" was held in Kunming's Dongfeng Square. 100,000 soldiers along with students and factory workers were mobilized to "fight a war of annihilation to take farmland from Dian Lake". The participants shouted the heroic slogan "March to Dian Lake! Take grain from Dian Lake!". Reclamation efforts were led by

People's Liberation Army The People's Liberation Army (PLA) is the military of the Chinese Communist Party (CCP) and the People's Republic of China (PRC). It consists of four Military branch, services—People's Liberation Army Ground Force, Ground Force, People's ...

Lieutenant General Lieutenant general (Lt Gen, LTG and similar) is a military rank used in many countries. The rank traces its origins to the Middle Ages, where the title of lieutenant general was held by the second-in-command on the battlefield, who was norma ...

Tan Furen. Immediately after taking office, Tan Furen announced that Dian Lake would be a model for the national "reclaiming land from the sea" campaign. The goal was to reclaim of land from Dian Lake to develop agriculture. Tan Furen personally spearheaded the reclamation project until his death by

assassination Assassination is the willful killing, by a sudden, secret, or planned attack, of a personespecially if prominent or important. It may be prompted by political, ideological, religious, financial, or military motives. Assassinations are orde ...

in 1970.

Pollution

Pollution Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...

is a major problem for the lake. Yunnan Province has long been primarily

agricultural Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created f ...

, but the Dianchi basin has witnessed high industrial growth and boasts the highest population density within Kunming City. In the late 1990’s to early 2000’s, Dian Lake was identified as one of the 3 top

water pollution Water pollution (or aquatic pollution) is the contamination of Body of water, water bodies, with a negative impact on their uses. It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and ...

concerns in China. The pollution peaked in 2009, at which time the water in Dian Lake was classified "worse than Grade 5" (too dangerous for human contact). Ninety percent of the city of Kunming's wastewater was dumped untreated into the lake until the first wastewater plant was built in 1990. Some experts estimated that over 55% of the lake's fish population has been killed off by this disease-ridden type of pollution
The China Environmental Statistical Yearbook
data reported that in 2013, 400 million tons of municipal sewage and 8 million tons of industrial waste water were dumped into Dian Lake of which only 1.5 million tons were treated before dumping. As of 2022, the water in the lake is still rated Grade 5, but is deemed to meet the functional requirements of a water environment. Historically, Dian Lake played an important role in regulating the microclimate of the surrounding area. It contributed to the productivity of Yunnan Province's industry, agriculture, husbandry, and fisheries. Because Dian Lake is a relatively closed lake with a slow water-exchange rate and low self-purification capacity, it is particularly susceptible to harmful algal blooms and heavy metal contamination. From 1966 to 1970, the lake reclamation project caused severe damage to

marsh In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p More in genera ...

wetlands in the Caohai area, which along with the large amounts of urban sewage and industrial wastewater traditionally discharged into the lake, exceeded its self-purification capacity and caused serious pollution. It has also been badly affected by

cyanobacteria Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...

outbreaks in recent decades. To control the pollution of Dian Lake, the Chinese government listed it as a national sewage treatment project in the ‘‘Three Rivers and Three Lakes’’ ( Liaohe, Huaihe, Haihe, Taihu, Chaohu, and Dianchi) scheme launched in 1995. The extensive land reclamation and urbanization projects have had long-lasting impacts on Dian Lake, necessitating ongoing rehabilitation and pollution control efforts to restore the lake's ecological balance. As a result, some wetland parks have been constructed in the lakeside zone to purify the water and create leisure areas for citizens. Wetland parks are mainly in the form of oxidation ponds. They are small water bodies with aquatic plants such as Phragmites australis, Typha orientalis, Acorus calamus, Eichhornia crassipes, Lemna minor, and Pistia stratiotes; outside the ponds, there are trails, trees, and lawns.

Biodiversity

Together with other Yunnan lakes ( Fuxian, Qilu, Yangzong, Xingyun, and Yilong), Dian Lake is recognized as an

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

. Among the three major Yunnan lakes with a high number of endemics, the other two being Fuxian and Erhai, the most drastic loss of biodiversity has been seen in the Dian Lake.Wang, Wang, Li, Du, Yang, Lassoie, and Hassan (2013). ''Six decades of changes in vascular hydrophyte and fish species in three plateau lakes in Yunnan, China.'' Biodivers. Conserv. 22: 3197–3221. doi: 10.1007/s10531-013-0579-0 Of the 25 native fish species and

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

in Dian Lake, 10 are endemic to the basin: ''

Acheilognathus elongatus The elongate bitterling (''Acheilognathus elongatus'') is a species of freshwater Actinopterygii, ray-finned fish in the Family (biology), family Acheilognathidae, the bitterlings. It is found only in shallow water areas along the shores of Lake ...

'', '' Anabarilius alburnops'', '' Anabarilius polylepis'', '' Cyprinus micristius'', '' Liobagrus kingi'', '' Pseudobagrus medianalis'', '' Silurus mento'', '' Sinocyclocheilus grahami'', '' Sphaerophysa dianchiensis'' and '' Xenocypris yunnanensis''. Today, the only endemic fish known to survive in the lake itself is ''Anabarilius alburnops'', but it is

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

. The remaining have not been recorded there since the 1990s or earlier, and most are presumed

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

. Two other species, '' Schizothorax grahami'' and '' Yunnanilus nigromaculatus'', are endemic to the general region, but have also disappeared from Dian Lake itself. Among the non-endemic natives, only gold fish and Asian swamp eel still live in Dian Lake. In contrast to the status of the natives, the lake is now home to more than 25 introduced fish species. The Yunnan lake newt (''Cynops wolterstorffi'') was also endemic to the lake, but it has not been seen since 1979 and is considered extinct. Many native hydrophytes have also disappeared from the lake.

Gallery

File:Dianchi Silhouette.jpg, Silhouette of trees along the coast of Dianchi File:昆明-滇池.JPG, Cable cars above Dianchi File:滇池.jpg, View of the lake from Xishan File:Dianchi Shelter.jpg, Shelter along Dianchi File:DianchiLotus.jpg, Lotuses in Dianchi File:Dianchi.jpg, Lotuses in Dianchi

References

External links

{{authority control National parks of China Lakes of Yunnan Geography of Kunming