The lakes of Bhutan comprise its glacial lakes and its natural mountain lakes. Bhutanese territory contains some 2,674 high altitude glacial lakes and subsidiary lakes, out of which 25 pose a risk of GLOFs.[1][2] There are also more than 59 natural non-glacial lakes in Bhutan, covering about 4,250 hectares (16.4 sq mi). Most are located above an altitude of 3,500 metres (11,500 ft), and most have no permanent human settlements nearby, though many are used for grazing yaks and may have scattered temporary settlements.[3][4]
Only four lakes are below an altitude of 2,000 metres (6,600 ft): the temperate Kabji-Hoka Tsho in Punakha District at 1,829 metres (6,001 ft); Luchika in Wangdue Phodrang at 1,830 metres (6,000 ft); Buli Tsho in Zhemgang at 1,372 metres (4,501 ft); and the subtropical Gulandi in Samdrup Jongkhar at 366 metres (1,201 ft).[3][4][5]
As phenomena of nature, all lakes in Bhutan are believed to be inhabited by spirits.[6]: 27 A handful of lakes in Bhutan are particularly sacred, most often connected to lives of Buddhist saints Guru Rimpoche and Pema Lingpa. For example, Membar Tsho ("Burning Lake"), in the Tang Valley near Bumthang, is heavily associated with Guru Rimpoche, who brought Buddhism to Bhutan and discovered his first terma in the lake in 1475.[7]: 21, 29, 177
Most natural lake names are denoted with the word tsho, meaning "lake" (Dzongkha: མཚོ་; Wylie: mtsho).[8] They may be identified as an individuals, pairs, or groups of lakes.
Glaciers in Bhutan cover a substantial portion of its northern regions.
Bhutan contains some 2,674 glacial lakes.[1][2] Some glacial lakes, such as Thorthormi Lake in Lunana Gewog, are not a single bodies of water but collections supraglacial ponds.[9] Most glacial lakes identified as potentially dangerous feed into the Manas River and Puna Tsang (Sankosh) River water systems of north-central Bhutan.[10] During a GLOF, residents of nearby downstream villages may have as little as twenty minutes to evacuate; floodwaters from one 1994 GLOF at Luggye lake took about seven hours to reach Punakha, some 90 kilometres (56 mi) downstream.[11]
Where glacial movement temporary blocks riverflows, downstream areas may be threatened by glacial lake outburst flood ("GLOFs").[12][13] Although GLOFs are not a new phenomenon in Bhutan, their frequency has risen in the past three decades.[1][14] Significant GLOFs occurred in 1957, 1960, 1968 and 1994, devastating lives and property downstream.[15] According to the Bhutan Department of Energy however, the majority of rivers in Bhutan are more susceptible to fluctuation with changing rainfall patterns than to flooding directly attributable to glacier or snow melt.[16]
For public safety, these glaciers and glacial lakes are maintained by the Ministry of Economic Affairs' Department of Geology and Mines, an executive (cabinet) agency of the government of Bhutan.[17] The Department, as part of its environmental "mitigation projects," aims to lower the levels of glacial lakes and thereby avert GLOF-related disaster. One such glacial lake mitigation project, for example, aimed to lower water levels by five meters over three years. The Department uses silent explosives and other means it considers environmentally friendly in order to minimize the ecological impact of its mitigation projects. These projects, however, remain difficult to conduct because of the weather, terrain, and relative lack of oxygen at the glacial lakes' altitudes. As of September 2010, GLOF early warning systems were slated for installation by mid-2011 in Punakha and Wangdue Phodrang Districts at a cost of USD4.2 million.[2][18]
Lists of lakes
List of non-glacial lakes
Naturally occurring mountain lakes, though today fewer than glacial lakes, include several historically and spiritually relevant bodies of water.
Located near Dhur, Animo Tsho sits at an elevation of 4,375 metres (14,354 ft) on the road from Bumthang to Lunana. It is a holy lake where speech is forbidden.[6]: 239
Chhiba Tsho is located below a pass at 4,500 metres (14,800 ft). On the other side of the pass lie Dagana Valley and the small, blue Langtsho ("Ox Lake").[6]: 205
Djule Tsho is located to the northwest of the sacred Animo Tsho at 4,190 metres (13,750 ft) near the Gongto La (Gokthong La) and Djule La passes. This pass marks the watershed of the Mangde Chhu (Trongsa Chhu), one of Bhutan's major river systems.[6]: 239
Drakey Pangtsho is a spiritual lake on the lap of Jowo Drake, where Guru Rinpoche had hidden sacred treasures in the 8th Century. This treasure lake is in the middle of a gently sloped rocky hill at an altitude of 4390 masl in the northern part of Paro Dzongkhag.[20]
Janye, or Jane, Tsho rests at 3,956 metres (12,979 ft) along the Druk Path Trail between Jimilang Tsho and Simkotra Tsho. It is often occupied by yak herders.[6]: 190
Jimilang rests at an elevation of 3,870 metres (12,700 ft) at the apex of the Druk Path Trail. Its name means "Sand Ox Lake," named after a legendary bull.[7]: 214 Also called Bimelang Tsho, this sacred lake is a meditation site. The lake contains many trout, and fishing there is allowed with permit.[6]: 188, 191
"Burning Lake", in the Tang Valley near Bumthang, is heavily associated with Guru Rimpoche, who brought Buddhism to Bhutan and discovered his first terma in the lake in 1475.[7]: 21, 29, 177
Om Tsho, also called Omtoe Tsho and Omta Tsho, lies at 4,665 metres (15,305 ft). It is a sacred lake, believed to be where Pema Lingpa found terton: cymbals, texts, and other artifacts hidden by Guru Rimpoche. There is a second smaller lake below the waterfall of Om Tsho at 4,150 metres (13,620 ft); both are located along the Snowman Trek.[6]: 141
The Tsho Phu are a pair of lakes along the Snowman Trek at 4,380 metres (14,370 ft).[7]: 221 Although they were stocked with brown trout in the 1960s, fishing there is prohibited.[6]: 149
Ada Tsho is beautifully located within the warm broadleaved forest near a paddy field.
List of glacial lakes
Glacial lakes in Bhutan far outnumber other kinds of lakes, and pose a particular risk to those living downstream in the event of a GLOF. Many of these lakes have appeared or grown after climate change, and the frequency at which they emit flood waters has increased. in recent history.
Below is a list of the major glacial lakes in Bhutan. Many lakes appear in clusters, and may someday merge; for example, the numerous glacial lakes of Laya and Lunana Gewogs lie mostly within Jigme Dorji National Park along a handful of major glaciers.
Luggye first appeared in 1967 atop its glacier. It has a depth of 142 metres (466 ft), and a width of 30 metres (98 ft). Luggye produced a significant GLOF in 1994.[9][21][22][23]
Wochey Lake lies at an altitude of 4,220 metres (13,850 ft), just below the Gokthong La pass,[7]: 239 on the single longest glacier in Bhutan at 20.1 kilometres (12.5 mi).[21]
^"༈ རྫོང་ཁ་ཨིང་ལིཤ་ཤན་སྦྱར་ཚིག་མཛོད། ༼མཚ-༽" [Dzongkha-English Dictionary: "MTSHA"]. Dzongkha-English Online Dictionary. Dzongkha Development Commission, Government of Bhutan. Archived from the original on 2011-08-25. Retrieved 2011-10-30.
^Iwata, Shuji (2010). Richard S. Williams, Jr & Jane G. Ferrigno (ed.). "Glaciers of Bhutan — An Overview"(PDF). Glaciers of Asia: U.S. Geological Survey Professional Paper 1386–F. USGS.