Pagsum Lake
{{short description|Lake in People's Republic of China}}
{{Infobox body of water
| name = Pagsum Co
| image = BasumTso-wiki.jpg
| caption = View north-east from Tashi Island
| image_bathymetry =
| caption_bathymetry =
|pushpin_map=Tibet
| location = Gongbo'gyamda County, Tibet
| coords = {{coord|30|00|51|N|93|57|01|E|region:CN-54_type:waterbody_source:kolossus-zhwiki|display=it}}
| type =
| inflow =
| outflow =
| catchment =
| basin_countries = China
| length = {{convert|18|km|abbr=on}}
| width =
| area = {{convert|27|km2|abbr=on}}
| depth =
| max-depth = {{convert|120|m|abbr=on}}
| volume =
| residence_time =
| shore =
| elevation = {{convert|3,700|m|abbr=on}}
| islands =
| cities =
}}
Dragsum Tsho ({{bo|t=བྲག་གསུམ་མཚོ་ |w=brag gsum mtsho |s=Draksum Tso}}, Pagsum Co ({{lang-zh|s=八松错, 巴松措 |t=八松錯 |p=Bāsōng Cuò}}), literally meaning “three rocks” in Tibetan,{{cite book|title=Xizang Diming : Bod ljoṅs sa miṅ; Place Names of the Xizing Autonomous Region|author=国家测绘局地名研究所 (National Surveying and Naming Research Institute)|publisher=China Tibetology Press (中国藏学出版社)|year=1995|isbn=7-80057-284-6|location=Beijing|page=15|script-title=zh:西藏地名 {{!}} བོད་ལྗོངས་ས་མིང།|trans-title=Tibetan Place Names}}; The name is sometimes confused with Basum (Basong Xiang {{lang|zh-hans|巴松乡}} / dba’ gsum {{bo-textonly|དབའ་གསུམ}}) in Tingri County, Shigatse, due to the similarity of the Chinese names. is a lake covering 28 square kilometres in Gongbo'gyamda County, Nyingchi of the Tibet Autonomous Region, China, approximately {{convert|300|km|abbr=on}} east of Lhasa. At 3,700 metres over sea level it is about 18 km long and has an average width of approximately {{convert|1.5|km|abbr=on}}. The deepest point of the green lake measures 120 metres. The lake is also known as Gongga Lake.{{cite book | title=大西藏之旅 | publisher=昭明出版社 | series=雲龍叢刊 | year=2000 | isbn=978-986-7938-21-3 | url=https://books.google.com/books?id=Dl3ZagxKpW0C&pg=PA299 | language=zh | access-date=2025-02-15 | page=299}}
Geography
Surrounded by dense primary forests of fir, spruce, and rhododendron, the lake hosts 195 native animal species and 242 phytoplankton varieties, including endemic fish like the naked carp (Gymnocypris spp.), which thrive in its oligotrophic waters. The northwestern shore features a 5 m² sacred boulder with a central perforation, believed to cleanse sins and cure illnesses through ritual passage.{{cite book | title=西藏园林植物生态环境效益定量研究 | publisher=Social Sciences Academic Press西藏园林植物生态效益及研究方法 | year=2014 | isbn=978-7-5097-6302-5 | url=https://books.google.com/books?id=B7l4EAAAQBAJ&pg=PA65 | language=zh | access-date=2025-02-15 | page=65}}{{cite book | title=系统科学视野下的世界级旅游目的地可持续发展研究：以西藏为例 | publisher=Social Sciences Academic Press | year=2014 | isbn=978-7-5097-6667-5 | url=https://books.google.com/books?id=i7l4EAAAQBAJ&pg=PA238 | language=zh | access-date=2025-02-15 | page=238}}
Culturally, Dragsum Tsho is central to the Kongpo people, a Tibetan subgroup known for unique traditions like polyandrous marriages and silver-ornamented attire35. The 7th-century Tsodzong Monastery on Drowa Island ({{lang-zh|扎西岛}}) exemplifies Nyingma school architecture, dedicated to Padmasambhava and adorned with ancient carvings of the deity Hayagriva.{{cite book | title=系统科学视野下的世界级旅游目的地可持续发展研究：以西藏为例 | publisher=Social Sciences Academic Press | year=2014 | isbn=978-7-5097-6667-5 | url=https://books.google.com/books?id=i7l4EAAAQBAJ&pg=PA241 | language=zh | access-date=2025-02-15 | page=241}} Annually on the 15th day of the fourth Tibetan month, pilgrims circumambulate the lake, tracing routes marked by King Gesar’s legendary arrow strikes and hoofprints of his warhorse embedded in shoreline rocks. The lake's designation as Tibet's first AAAAA-rated scenic area in 1994 underscores its dual role as an ecological sanctuary and living cultural archive.{{cite book | title=西藏行全攻略 | publisher=香港中国路有出版社 | year=2020 | isbn=978-988-8179-77-0 | url=https://books.google.com/books?id=9bHyDwAAQBAJ&pg=PA71 | language=zh | access-date=2025-02-15 | page=71}}{{cite book | title=蓮師在西藏：大藏區蓮師聖地巡禮 | publisher=橡树林文化出版社 | series=朝聖系列 | year=2018 | isbn=978-986-5613-85-3 | url=https://books.google.com/books?id=_SiCDwAAQBAJ&pg=PA164 | language=zh | access-date=2025-02-15 | page=164}}
Climate
{{Weather box|width=auto
|metric first=y
|single line=y
|collapsed = Y
|location = Pagsum Lake
|Jan high C = 5.2
|Feb high C = 6.9
|Mar high C = 10.3
|Apr high C = 13.8
|May high C = 17.0
|Jun high C = 19.7
|Jul high C = 20.5
|Aug high C = 20.3
|Sep high C = 18.4
|Oct high C = 14.7
|Nov high C = 10.1
|Dec high C = 6.6
|Jan mean C = −2.4
|Feb mean C = −0.1
|Mar mean C = 3.3
|Apr mean C = 6.8
|May mean C = 10.4
|Jun mean C = 13.7
|Jul mean C = 14.8
|Aug mean C = 14.4
|Sep mean C = 12.5
|Oct mean C = 8.0
|Nov mean C = 2.6
|Dec mean C = −1.1
|Jan low C = -10.0
|Feb low C = −7.1
|Mar low C = −3.7
|Apr low C = −0.2
|May low C = 3.8
|Jun low C = 7.7
|Jul low C = 9.1
|Aug low C = 8.5
|Sep low C = 6.6
|Oct low C = 1.4
|Nov low C = −4.9
|Dec low C = −8.8
|precipitation colour = green
|Jan precipitation mm = 2
|Feb precipitation mm = 3
|Mar precipitation mm = 10
|Apr precipitation mm = 27
|May precipitation mm = 51
|Jun precipitation mm = 108
|Jul precipitation mm = 117
|Aug precipitation mm = 100
|Sep precipitation mm = 89
|Oct precipitation mm = 28
|Nov precipitation mm = 5
|Dec precipitation mm = 2
|source 1 = [https://en.climate-data.org/location/993629/ Climate-Data.org]
}}