View source for Dian Lake

{{Short description|Lake in Yunnan, China}}
{{Infobox body of water
 | name = Dian Lake
 | image = 正大河与金家河交汇入滇池口远眺西山 - panoramio (2).jpg
 | caption =
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 | pushpin_map = China#Yunnan
 | pushpin_map_caption = Location in Yunnan
 | location = [[Kunming]], [[Yunnan]]
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 | type = [[Fresh water|Freshwater]]
 | inflow = 
 | outflow = [[Pudu River]]
 | catchment =
 | basin_countries = China
 | length = {{convert|39|km|mi|abbr=on}}
 | width = 
 | area = {{convert|298|km2|sqmi|abbr=on}}
 | depth = {{convert|4.4|m|ft|abbr=on}}
 | max-depth = 
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 | elevation = {{convert|1886.5|m|ft|abbr=on}}
 | islands = 
 | cities = 
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[[File:DSCN6666-s.jpg|thumb|Dianchi Lake (2005)]]
[[File:Dianchi boats 1940s.jpg|thumb|Chinese sailing junks on Lake Dian, circa 1940s]]
'''Dian Lake''' ({{zh|c={{linktext|滇池}} |p=Diānchí}}), also known as '''Dianchi, Dianchi Lake, Lake Dian''' and '''Kunming Lake''', is a fault lake located on the [[Pudu River|Puduhe]]-[[Western Mountains|Xishan]] fault in [[Kunming]], [[Yunnan]], China at 24°23′–26°22′ N, 102°10′–103°40′ E. Its nickname is the "Sparkling Pearl Embedded in a Highland" ({{zh|高原明珠}}; [[pinyin]]: ''Gāoyuánmíngzhū'').<ref>{{cite news |author1=唐卫彬 |author2=伍晓阳 |date=2017-02-08 |title="高原明珠"复苏记——昆明滇池迎来31年来最好水质 |url=http://www.xinhuanet.com/local/2017-02/08/c_1120432919.htm |newspaper=[[Xinhua News Agency|Xinhua Net]] |access-date=2020-10-17 |archive-date=2020-10-20 |archive-url=https://web.archive.org/web/20201020233912/http://www.xinhuanet.com/local/2017-02/08/c_1120432919.htm }}</ref> It is the model for the [[Kunming Lake (Beijing)|Kunming Lake]] in [[Beijing]]'s [[Summer Palace]]. Its name is the source of [[Yunnan]]'s [[Chinese provincial abbreviations|Chinese abbreviation]] {{lang|zh|{{linktext|滇}}}}.

Dian Lake is a shallow freshwater [[Fault (geology)|fault]] [[lake]]. The Lake is 40&nbsp;km long, running from north to south, and has an average width of 7&nbsp;km with the widest point being 12.5&nbsp;km. The lake is 1886&nbsp;meters above sea level and has 150&nbsp;km of coastline. The lake's drainage area has a monsoon-affected subtropical highland climate ([[Köppen climate classification|Köppen]] ''Cwb''), with an average annual temperature of 14.4&nbsp;°C, a frost-free period of 227&nbsp;days, and an annual precipitation of 1036&nbsp;mm.{{Citation needed|date=July 2024}} The lake covers {{convert|298|km2|sqmi|abbr=on}}. The lake has an average depth of {{convert|4.4|m|ft|abbr=on}},<ref>{{Cite journal |last1=徐晓梅 |last2=吴雪 |last3=何佳 |last4=王丽 |last5=张英 |last6=杨艳 |last7=陈云波 |last8=叶海云 |date=2016-04-14 |title=滇池流域水污染特征 (1988-2014年) 及防治对策 |url=http://www.jlakes.org/ch/reader/view_abstract.aspx?doi=10.18307/2016.0302 |journal=湖泊科学 |language=zh |volume=28 |issue=3 |pages=476–484 |doi=10.18307/2016.0302|url-access=subscription }}</ref> and is divided into two parts by an artificial [[Dyke (embankment)|dike]]. The northern end of the lake is called Caohai ({{zh|草海}}; [[pinyin]]: ''Cáohǎi'') and has a surface area of 7.5&nbsp;km<sup>2</sup> and an average depth of 2.5&nbsp;meters.  The southern end of the lake, comprising the majority of the lake, is called Waihai ({{zh|外海}}; [[pinyin]]: ''Wàihǎi'') and has a surface area of 292&nbsp;km<sup>2</sup> and an average depth of 4.4&nbsp;m. The water flows out of the lake to the west via the [[Pudu River]] ([[Simplified Chinese characters|Chinese]]: 普渡河; [[pinyin]]: ''Pǔdù Hé'') which eventually joins the [[Yangtze|Yangtze River]] before finally reaching the [[Pacific Ocean]].<ref name=":0">{{Cite journal |last=Jin |first=Xiangcan |date=27 February 2006 |title=Dianchi Lake: Experience and Lessons Learned Brief |url=https://www.ilec.or.jp/wp-content/uploads/pub/11_Lake_Dianchi_27February2006.pdf |journal=Chinese Research Academy of Environmental Sciences}}</ref> Dian Lake is the sixth largest lake in China and the largest lake in [[Yunnan|Yunnan Province]].

==Etymology==

The [[Chinese character]] for the lake ({{zh|滇}}; [[pinyin]]: ''Diān'') is a [[Phono-semantic compound|phonosemantic compound]] of the [[Chinese radical|radical]] {{lang|zh|{{linktext|氵}}}}("water") and the character {{lang|zh|{{linktext|真}}}} ("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 (China)|Bo people]] and means [[Depression (geology)|basin]].<ref>{{cite book |last=You |first=Zhong |title=云南地方沿革史 |trans-title=Local History of Yunnan |language=zh |location=[[Kunming]] |publisher=[[Yunnan People's Publishing House]] |date=1990 |isbn=7-222-00606-0 }}</ref> The character 滇 has been used as the name of the lake since at least 109 BC, when the [[Han dynasty]] 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 ({{lang|zh|爨}}) during the first millennium AD. At that time, it was known as '''Kunchuan''' ({{lang|zh|昆川}}).{{citation needed|date=November 2013}}.

During the [[Three Kingdoms]] period (220-280 CE), Dian Lake was where the forces of [[Shu Han]], led by their chancellor [[Zhuge Liang]], visited in triumph after [[Zhuge Liang's Southern Campaign|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",<ref>{{Cite journal |last=Ho |first=Peter |date=July 2003 |title=Mao's War against Nature? The Environmental Impact of the Grain-First Campaign in China |url=https://www.journals.uchicago.edu/doi/10.2307/3182245 |journal=The China Journal |language=en |volume=50 |issue=50 |pages=37–59 |doi=10.2307/3182245 |jstor=3182245 |issn=1324-9347|url-access=subscription }}</ref> 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!".<ref>{{Cite web |date=27 August 2022 |title=Old Photos, Dianchi Lake in the 1960s and 1970s, land reclamation project. |website=[[Sohu]] |url=https://www.sohu.com/a/580380721_241009?scm=}}</ref> Reclamation efforts were led by [[People's Liberation Army]] [[Lieutenant general|Lieutenant General]] [[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 {{convert mu|30,000|mu|ha|lk=in}} of land from Dian Lake to develop agriculture. Tan Furen personally spearheaded the reclamation project until his death by [[assassination]] in 1970.<ref>{{Cite web |title=谭甫仁017凶案(组图)_文化_新浪网 |url=https://cul.sina.com.cn/o/2006-02-14/1711153769.html |access-date=2024-07-03 |website=cul.sina.com.cn}}</ref>

==Pollution==
[[Pollution in China|Pollution]] is a major problem for the lake. Yunnan Province has long been primarily [[Agriculture|agricultural]], but the Dianchi basin has witnessed high industrial growth and boasts the highest population density within Kunming City.<ref name="link.springer.com">{{Cite journal |last1=Liu |first1=Wenbin |last2=Wang |first2=Shengrui |last3=Zhang |first3=Li |last4=Ni |first4=Zhaokui |date=September 2015 |title=Water pollution characteristics of Dianchi Lake and the course of protection and pollution management |url=http://link.springer.com/10.1007/s12665-015-4152-x |journal=Environmental Earth Sciences |language=en |volume=74 |issue=5 |pages=3767–3780 |doi=10.1007/s12665-015-4152-x |bibcode=2015EES....74.3767L |issn=1866-6280|url-access=subscription }}</ref>

In the late 1990's to early 2000's, Dian Lake was identified as one of the 3 top [[water pollution]] concerns in China.<ref name="hess.copernicus.org">{{Cite journal |last1=Zhang |first1=T. |last2=Zeng |first2=W. H. |last3=Wang |first3=S. R. |last4=Ni |first4=Z. K. |date=2014-04-23 |title=Temporal and spatial changes of water quality and management strategies of Dianchi Lake in southwest China |url=https://hess.copernicus.org/articles/18/1493/2014/ |journal=Hydrology and Earth System Sciences |language=en |volume=18 |issue=4 |pages=1493–1502 |doi=10.5194/hess-18-1493-2014 |doi-access=free |bibcode=2014HESS...18.1493Z |issn=1607-7938}}</ref> The pollution peaked in 2009, at which time the water in Dian Lake was classified "worse than Grade 5" (too dangerous for human contact).<ref name=":0" /> Ninety percent of the city of Kunming's wastewater was dumped untreated into the lake until the first [[Water treatment|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. [http://mp.weixin.qq.com/s?__biz=MzA3NjM4MjcxNQ==&mid=402202506&idx=1&sn=4bbd8379f7a623458de2c17ff803ca67&scene=5&srcid=1217oi2BZB8TzoeNuV3xs8CJ#rd 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.<ref>{{Cite web |date=2016-01-27 |title=Kunming's Stinky Lake, Beijing's Saving Winds |url=https://www.chinafile.com/reporting-opinion/green-space/kunming-stinky-lake-beijing-saving-winds |access-date=2024-07-03 |website=ChinaFile |language=en}}</ref> 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.<ref>{{Cite web |title=云南通报碧水保卫战重点工作进展 2019年全省河流总体水质为良好_重庆市生态环境局 |url=http://sthjj.cq.gov.cn/zwgk_249/gndt/202004/t20200428_7279148_wap.html |access-date=2022-03-29 |website=sthjj.cq.gov.cn}}</ref>

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.<ref>{{Cite journal |last=Jing |first=Huang Ke |date=August 2006 |title=Evaluating comprehensive quality of sediment in Dianchi Lake using adjusted AHP method and 137Cs dating |journal=Department of Urban and Resources Science, Nanjing University (Chinese)|volume=27 |issue=8 |pages=1531–1536 |pmid=17111606 }}</ref> 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 bloom]]s and [[Toxic heavy metal|heavy metal contamination]]. From 1966 to 1970, the lake reclamation project caused severe damage to [[marsh]] 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]] outbreaks in recent decades.<ref>{{Cite journal |last1=Luo |first1=Yi |last2=Zhang |first2=Yueyue |last3=Yang |first3=Kun |last4=Yu |first4=Zhenyu |last5=Zhu |first5=Yu |date=2019 |title=Spatiotemporal Variations in Dianchi Lake's Surface Water Temperature From 2001 to 2017 Under the Influence of Climate Warming |journal=IEEE Access |volume=7 |pages=115378–115387 |doi=10.1109/ACCESS.2019.2935767 |bibcode=2019IEEEA...7k5378L |issn=2169-3536|doi-access=free }}</ref> 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'' ([[Liao River|Liaohe]], [[Huai River|Huaihe]], [[Hai River|Haihe]], [[Lake Tai|Taihu]], [[Chaohu]], and Dianchi) scheme launched in 1995.<ref name="hess.copernicus.org"/> 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.<ref>{{Cite journal |last1=Wu |first1=Qiuju |last2=Yang |first2=Renyi |last3=Yang |first3=Zisheng |date=2022-09-13 |title=A Study on the Rationality of Land Use Change in the Dianchi Basin during the Last 40 Years under the Background of Lake Revolution |journal=Sustainability |language=en |volume=14 |issue=18 |article-number=11479 |doi=10.3390/su141811479 |doi-access=free |issn=2071-1050}}</ref> 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|Pistia stratiotes]];<ref name="link.springer.com"/> outside the ponds, there are trails, trees, and lawns.

==Biodiversity==
Together with other Yunnan lakes ([[Fuxian Lake|Fuxian]], [[Qilu Lake|Qilu]], [[Yangzong Lake|Yangzong]], [[Xingyun Lake|Xingyun]], and [[Yilong Lake|Yilong]]), Dian Lake is recognized as an [[ecoregion]].<ref>Freshwater Ecoregions of the World: ''[http://www.feow.org/ecoregions/details/yunnan_lakes Yunnan Lakes.] {{Webarchive|url=https://web.archive.org/web/20170116170011/http://www.feow.org/ecoregions/details/Yunnan_Lakes |date=2017-01-16 }}'' Retrieved 15 February 2017.</ref> Among the three major Yunnan lakes with a high number of [[Endemism|endemics]], the other two being [[Fuxian Lake|Fuxian]] and [[Erhai Lake|Erhai]], the most drastic [[Biodiversity loss|loss of biodiversity]] has been seen in the Dian Lake.<ref name=Wang2013>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]]</ref> Of the 25 native fish species and [[subspecies]] in Dian Lake, 10 are endemic to the [[Drainage basin|basin]]: ''[[Acheilognathus elongatus]]'', ''[[Anabarilius alburnops]]'', ''[[Anabarilius polylepis]]'', ''[[Cyprinus micristius]]'', ''[[Liobagrus kingi]]'', ''[[Pseudobagrus medianalis]]'', ''[[Silurus mento]]'', ''[[Sinocyclocheilus grahami]]'', ''[[Sphaerophysa dianchiensis]]'' and ''[[Xenocypris yunnanensis]]''.<ref name=Wang2013/> Today, the only endemic fish known to survive in the lake itself is ''Anabarilius alburnops'',<ref name=Wang2013/> but it is [[Endangered species|endangered]].<ref>{{Cite iucn | author = Chen, X.-Y. | author2 = Du, L.-N. | name-list-style = amp | title = ''Anabarilius alburnops'' | volume = 2008 | article-number = e.T135163A4069106 | date = 2008 | doi = 10.2305/IUCN.UK.2008.RLTS.T135163A4069106.en | access-date = 14 January 2018}}</ref> The remaining have not been recorded there since the 1990s or earlier, and most are presumed [[extinct]].<ref name=Wang2013/><ref>Nguyen, T.T.T., and S. S. De Silva (2006). ''Freshwater finfish biodiversity and conservation: an Asian perspective.'' Biodiversity & Conservation 15(11): 3543-3568</ref> Two other species, ''[[Schizothorax grahami]]'' and ''[[Yunnanilus nigromaculatus]]'', are endemic to the general region, but have also disappeared from Dian Lake itself.<ref>{{Cite iucn | author = Chen, X.-Y. | author2 = Yang, J. | name-list-style = amp | title = ''Schizothorax grahami'' | volume = 2008 | article-number = e.T135149A4067169 | date = 2008 | doi = 10.2305/IUCN.UK.2008.RLTS.T135149A4067169.en | access-date = 14 January 2018}}</ref><ref>{{Cite iucn | author = Chen, X.-Y. | title = ''Yunnanilus nigromaculatus'' | volume = 2011 | article-number = e.T23175A9425121 | date = 2011 | doi = 10.2305/IUCN.UK.2011-2.RLTS.T23175A9425121.en | access-date = 14 January 2018}}</ref> 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 species|introduced]] fish species.<ref name=Wang2013/>

The [[Yunnan lake newt]] (''Cynops wolterstorffi'') was also endemic to the lake, but it has not been seen since 1979 and is considered extinct.<ref name=IUCN>{{Cite iucn | author = Yang Datong | author2 = Michael Wai Neng Lau | title = ''Hypselotriton wolterstorffi'' | volume = 2004 | article-number = e.T59445A11942589 | date = 2004 | doi = 10.2305/IUCN.UK.2004.RLTS.T59445A11942589.en | access-date = 14 January 2018}}</ref>

Many native [[hydrophyte]]s have also disappeared from the lake.<ref name=Wang2013/>

==Gallery==

<gallery mode="packed" heights="170">
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 [[Western Hills Park|Xishan]]
File:Dianchi Shelter.jpg|Shelter along Dianchi
File:DianchiLotus.jpg|Lotuses in Dianchi
File:Dianchi.jpg|Lotuses in Dianchi
</gallery>

==See also==
*[[Zheng He]]
*[[Dian Kingdom]]
*[[List of lakes in China]]

==References==
{{Reflist}}

==Further reading==
*[http://etd.uwaterloo.ca/etd/ymu2006.pdf Developing a Suitability Index for Residential Land Use: A case study in Dianchi Drainage Area] (2006)

==External links==
{{Commons category|Dian Lake}}
*[https://web.archive.org/web/20050322000942/http://www.dianchi.gov.cn/firste.htm Kunming Dianchi Administration Bureau]

{{Lakes in Yunnan-Guizhou Plateau}}
{{National parks of China}}
{{Lakes of China}}
{{Yunnan topics}}
{{Yunnan}}

{{authority control}}

[[Category:National parks of China]]
[[Category:Lakes of Yunnan]]
[[Category:Geography of Kunming]]