View source for Geography of Bhutan

{{Short description|none}} <!-- This short description is INTENTIONALLY "none" - please see WP:SDNONE before you consider changing it! -->
{{Use dmy dates|date=May 2022}}
{| border=1 align=right cellpadding=4 cellspacing=0 width=300 style="margin: 0.5em 0 1em 1em; background: #f9f9f9; border: 1px #aaaaaa solid; border-collapse: collapse; font-size: 95%;"
|+<big><big>'''Bhutan'''</big></big>
|-
| style="background:#efefef;" align="center" colspan="2" |
{| border="0" cellpadding="2" cellspacing="0"
|-
| align="center" width="140px" | [[File:BhutanOMC.png|400px|thumb|right|Bhutan's towns and villages]]
|}
|-
| '''[[Continent]]''' || Asia
|-
| '''[[Subregion]]''' || [[South Asia]]
|-
| '''[[Geographic coordinates]]''' || {{Coord|27|30|N|90|30|E|type:country}}
|-
| '''Area'''<br>&nbsp;- Total <br>&nbsp;- Water
| [[List of countries by area|Ranked 137th]]<br>{{convert|38394|km2|sqmi|1|abbr=on}} <br> {{convert|0|km2|sqmi|abbr=on}} (landlocked)
|-
| '''Coastline''' || {{convert|0|km|mi|abbr=on}}
|-
| '''Land boundaries''' || {{convert|1136|km|mi|0|abbr=on}}
|-
| '''Countries bordered''' || China {{convert|477|km|mi|0|abbr=on}}, <br> India {{convert|659|km|mi|0|abbr=on}}
|-
| '''Highest point''' || [[Gangkhar Puensum]], {{convert|7570|m|ft|0|abbr=on}} <ref name=cia>{{cite web|url=https://www.cia.gov/the-world-factbook/countries/bhutan/|work=[[World Factbook]] |publisher=[[Central Intelligence Agency|CIA]] |title=Bhutan |date=22 March 2011 |access-date=3 April 2011}}</ref>
|-
| '''Lowest point''' || [[Drangme Chhu]], {{convert|97|m|ft|0|abbr=on}} <ref name=cia/>
|-
| '''Longest river''' ||
|-
| '''Largest inland body of water''' ||
|-
| '''Land Use'''<br>&nbsp;- Arable land<br>&nbsp;- Permanent crops<br>&nbsp;- Other ||<br>2.62% <br>0.34% <br>97.27% (2012 est.)
|-
| '''Irrigated Land''' || {{convert|319.1|km2|sqmi|1|abbr=on}} (2010)
|-
| '''[[Climate]]''': || Varies; tropical in southern plains; cool winters and hot summers in central valleys; severe winters and cool summers in Himalayas
|-
| '''Natural resources''' || [[timber]], hydropower, [[gypsum]], [[calcium carbonate]]
|-
| '''Natural hazards''' || Violent storms from the Himalayas are the source of the country's name, which translates as Land of the Thunder Dragon; frequent landslides during the rainy season
|-
| '''Environmental issues''' || [[soil erosion]]; limited access to potable water
|}

[[File:Bhutan topo en.jpg|thumb|right|250px|Topographic map of Bhutan]]

[[Bhutan]] is a [[List of sovereign states|sovereign country]] at the crossroads of [[East Asia]] and [[South Asia]], located towards the eastern extreme of the [[Himalayas]] mountain range. It is fairly evenly sandwiched between the sovereign territory of two nations: first, the [[People's Republic of China]] (PRC) on the north and northwest. There are approximately {{Convert|477|km}} of border with the country's [[Tibet Autonomous Region]] (TAR), or simply Tibet. The second nation is the [[India|Republic of India]] on the south, southwest, and east; there are approximately {{Convert|659|km}} with the states of [[Arunachal Pradesh]], [[Assam]], [[West Bengal]], and [[Sikkim]], in clockwise order from the kingdom. Bhutan's total borders amount to approximately {{Convert|1139|km}}.

Bhutan is a very compact landlocked nation, but with just a small bit more [[length]] than [[width]]. The nation's territory totals an approximate {{Convert|38394|km2}}. Because of its inland, [[landlocked]] status, it controls no [[territorial waters]]. Bhutan's territory used to extend south into present-day Assam, including the [[protectorate]] of [[Cooch Behar]], but, starting from 1772, the British [[East India Company]] (EIC) began to push back the borders through a number of wars and treaties, severely reducing Bhutan's size until the [[Treaty of Sinchula]] of 1865, when some border land was ceded back. Later, many of these territories were permanently lost to [[British India]] under the [[Treaty of Punakha]] and today remains a part of modern-day India.

==Political geography==
{{Unsourced section|date=May 2024}}
Bhutan is divided into 20 [[dzongkhag]]s (districts), and further into 205 [[Gewogs of Bhutan|gewog]]s (village blocks). Gewogs are in turn divided into numerous [[thromde]]s (municipalities) for administration.{{Cn|date=May 2024}}

==Physical geography==
[[File:GangkharPuensum3.jpg|thumb|right|240px|Gangkhar Puensum from Ura La, Bhutan]]

The [[Himalaya]] [[mountains of Bhutan]] dominate the north of the country, where peaks can easily reach {{convert|7000|m|ft|0}}; the highest point in Bhutan is [[Gangkhar Puensum]], which has the distinction of being the [[highest unclimbed mountain]] in the world, at {{convert|7570|m|ft}}.<ref name=cia/> Weather is extreme in the mountains: the high peaks have perpetual snow, and the lesser mountains and hewn gorges have high winds all year round, making them barren brown wind tunnels in summer, and frozen wastelands in winter. The [[blizzard]]s generated in the north each winter often drift southward into the central [[Highland (geography)|highlands]].

Below the rock and ice of the highest peaks lies an extensive arc of [[Eastern Himalayan alpine shrub and meadows]], which contain, in additions to grasslands, a wide variety of [[rhododendron]]s and [[herbaceous plant]]s.

The highlands are the most populous part of the nation; the [[Capital (political)|capital]] [[Thimphu]] lies in the western region. The region is characterised by its many rivers (flowing into India's [[Brahmaputra]]), its isolated valleys that house most of the population, and the expansive forests that cover seventy per cent of the nation. The highlands have [[Eastern Himalayan subalpine conifer forests]] at higher elevations and [[Eastern Himalayan broadleaf forests]] at lower elevations. Winters are cold, summer are hot; the rainy season is accompanied with high-frequency landslides.

The [[valleys of Bhutan]] are linked by a series of passes ("La" in [[Dzongkha]]). Between the Haa Valley and [[Paro Valley]] is the Chele La ({{convert|3780|m|ft|0}}). The Chele La is the highest pass crossed by a Bhutanese highway. The [[Lateral Road]] from Thimphu to [[Punakha]] crosses the Dochu La ({{convert|3116|m|ft|0}}), which features 108 [[chortens]] built to commemorate the expulsion of Assamese guerrillas. East of [[Wangdue Phodrang]] is the Pele La ({{convert|3390|m|ft|0}}). Continuing to the east along the main highway, other major passes include the Yotang La, Shertang La, Wangthang La, [[Thrumshing La]] and Kori La ({{convert|2298|m|ft|0}}).

The extreme southern strip of the nation consists mostly of [[Himalayan subtropical broadleaf forests]] that grade into the tropical plains of the [[Terai-Duar savanna and grasslands]], more typical of India. It is largely agricultural land, producing mostly [[rice]]. Only two per cent of Bhutan is [[arable land]], with most of it focused here.

Centuries of [[isolationism]], a small [[demographics of Bhutan|population]], and topographical extremes have led to Bhutan maintaining one of the most intact [[ecosystem]]s in the world. The country ranks amongst the top ten countries in the world in terms of species density (species richness per unit area). Over fifty-five hundred varieties of plant life exist, including around 300 medicinal ones. More than 770 species of avifauna and more than 165 species of mammals are known to exist, including many rare and endangered species like the [[red panda]], [[snow leopard]], and [[golden langur]].

==Strategic location==
{{Unsourced section|date=May 2024}}
Bhutan, situated between India and China, is a potential [[Sino-Indian relations|Sino-Indian]] battleground; India currently has more political influence in the nation. This stems from two things: the fact that after the [[British Raj|British]] granted sovereignty to their [[South Asia]]n possessions, Bhutan, a [[protectorate]], was never put under the administration of India, except for its Foreign Relation Policies under the Indo-Bhutan Treaty of 1949. The [[Indian Army]] patrols Bhutan's frontiers and has played a major role in the development of the country's road infrastructure. Additionally, the [[Government of India]] continues to provide approximately 60% of Bhutan's government finances.

The second reason comes from the aggression against Tibet by China from 1949 to 1959; the [[Tibetan people|Tibetans]] have strong cultural, historical, and religious connections to Bhutan.

Bhutan controls several strategic mountain passes through the [[Himalayas]], allowing travel between Tibet and [[Assam]]. These passes are also the only way into the kingdom, and, coupled with its centuries-old policies of [[isolationism]], it has been called the "Mountain Fortress of the Gods." The heartland of Bhutan has never been successfully invaded; the British, while establishing a protectorate over the nation, did so with threats to the low-lying territories below the highlands.

==Climate==
[[File:Koppen-Geiger_Map_v2_BTN_1991–2020.svg|thumb|Köppen-Geiger climate classification map for Bhutan]]
Bhutan's climate is as varied as its altitudes and, like India's, is affected by monsoons. Western Bhutan is particularly affected by [[Monsoon of South Asia|monsoons]] that bring between 60 and 90 per cent of the region's rainfall. The climate is humid and subtropical in the southern plains and foothills, temperate in the inner Himalayan valleys of the southern and central regions, and cold in the north, with year-round snow on the main Himalayan summits.<ref name=CSc>{{Country study|author=Robert L. Worden |country=Bhutan |section=Climate |abbr=bt |editor=Andrea Matles Savada |date=September 1991 |pd=yes}}</ref>

Temperatures vary according to elevation. Temperatures in [[Thimphu]], located at {{convert|2200|m|ft|0}} above sea level in west-central Bhutan, range from approximately {{convert|15|to|26|C|F|1}} during the monsoon season of June through September but drop to between about {{convert|-4|and|16|C|F|1}} in January. Most of the central portion of the country experiences a cool, temperate climate year-round. In the south, a hot, humid climate helps maintain a fairly even temperature range of between {{convert|15|and|30|C|F}} year-round, although temperatures sometimes reach {{convert|40|°C}} in the valleys during the summer.<ref name=CSc/>

Annual precipitation ranges widely in various parts of the country. In the severe climate of the north, there is only about {{convert|40|mm|in|1}} of annual precipitation—primarily snow. In the temperate central regions, a yearly average of around {{convert|1000|mm|in|1}} is more common, and {{convert|7800|mm|in|1}} per year has been registered at some locations in the humid, subtropical south, ensuring the thick tropical forest, or savanna. Thimphu experiences dry winter months (December through February) and almost no precipitation until March, when rainfall averages {{convert|20|mm|in|2}} a month and increases steadily thereafter to a high of {{convert|220|mm|in|1}} in August for a total annual rainfall of nearly {{convert|650|mm|in|1}}.<ref name=CSc/>

Bhutan's generally dry spring starts in early March and lasts until mid-April. Summer weather commences in mid-April with occasional showers and continues through the pre-monsoon rains of late June. The summer monsoon lasts from late June through late September with heavy rains from the southwest. The monsoon weather, blocked from its northward progress by the Himalayas, brings heavy rains, high humidity, flash floods and landslides, and numerous misty, overcast days. Autumn, from late September or early October to late November, follows the rainy season. It is characterised by bright, sunny days and some early snowfalls at higher elevations. From late November until March, winter sets in, with frost throughout much of the country and snowfall common above elevations of {{convert|3000|m|ft|0}}. The winter northeast monsoon brings gale-force winds down through high mountain passes.<ref name=CSc/>

{{Weather box
|location = Thimphu-Simtokha (1996-2017)
|metric first = yes
|single line = yes
|width = auto
|collapsed = no
|Jan high C = 14.8
|Feb high C = 16.6
|Mar high C = 19.3
|Apr high C = 22.4
|May high C = 24.8
|Jun high C = 26.7
|Jul high C = 27.0
|Aug high C = 27.3
|Sep high C = 26.0
|Oct high C = 23.7
|Nov high C = 19.7
|Dec high C = 16.6
|year high C = 
|Jan mean C = 6.3
|Feb mean C = 8.5
|Mar mean C = 11.6
|Apr mean C = 15.1
|May mean C = 18.2
|Jun mean C = 21.0
|Jul mean C = 21.8
|Aug mean C = 21.7
|Sep mean C = 20.3
|Oct mean C = 16.3
|Nov mean C = 11.5
|Dec mean C = 7.9
|year mean C = 
|Jan low C = -2.2
|Feb low C = 0.3
|Mar low C = 3.8
|Apr low C = 7.9
|May low C = 11.6
|Jun low C = 15.3
|Jul low C = 16.5
|Aug low C = 16.1
|Sep low C = 14.6
|Oct low C = 9.0
|Nov low C = 3.2
|Dec low C = -0.8
|year low C = 8.0
|Jan record high C = 24.0
|Feb record high C = 25.0
|Mar record high C = 28.0
|Apr record high C = 30.0
|May record high C = 32.2
|Jun record high C = 32.0
|Jul record high C = 33.0
|Aug record high C = 32.5
|Sep record high C = 31.0
|Oct record high C = 31.0
|Nov record high C = 27.0
|Dec record high C = 24.0
|Jan record low C = -8.5
|Feb record low C = -7.0
|Mar record low C = -7.0
|Apr record low C = -2.0
|May record low C = 2.5
|Jun record low C = 8.0
|Jul record low C = 11.0
|Aug record low C = 9.0
|Sep record low C = 6.0
|Oct record low C = -3.0
|Nov record low C = -6.0
|Dec record low C = -7.5
|Jan rain mm = 6.3
|Feb rain mm = 9.2
|Mar rain mm = 20.4
|Apr rain mm = 29.9
|May rain mm = 49.8
|Jun rain mm = 97.7
|Jul rain mm = 152.8
|Aug rain mm = 120.8
|Sep rain mm = 73.9
|Oct rain mm = 43.1
|Nov rain mm = 1.2
|Dec rain mm = 3.7
|rain colour = green
|year rain mm = 608.9
|Jan humidity = 68.6
|Feb humidity = 62.6
|Mar humidity = 62.8
|Apr humidity = 60.2
|May humidity = 63.2
|Jun humidity = 67.0
|Jul humidity = 72.7
|Aug humidity = 72.2
|Sep humidity = 71.2
|Oct humidity = 66.6
|Nov humidity = 62.1
|Dec humidity = 64.0
|source 1 = National Center for Hydrology and Meteorology<ref>{{cite web
| url = https://www.nchm.gov.bt/attachment/ckfinder/userfiles/files/Climate%20Data%20Book%20of%20Bhutan%2C%202018.pdf
| title = Climate Data Book of Bhutan, 2018
| publisher = [[National Center for Hydrology and Meteorology]]
| accessdate = 13 July 2021
}}</ref>
}}

{{Weather box
|location = Phuntsholing (1996-2017)
|metric first = yes
|single line = yes
|width = auto
|collapsed = no
|Jan high C = 23.9
|Feb high C = 26.6
|Mar high C = 29.8
|Apr high C = 31.1
|May high C = 32.3
|Jun high C = 32.3
|Jul high C = 31.9
|Aug high C = 32.3
|Sep high C = 31.7
|Oct high C = 31.2
|Nov high C = 28.7
|Dec high C = 25.4
|year high C = 
|Jan mean C = 18.6
|Feb mean C = 21.5
|Mar mean C = 24.2
|Apr mean C = 25.6
|May mean C = 27.0
|Jun mean C = 27.7
|Jul mean C = 27.8
|Aug mean C = 28.1
|Sep mean C = 27.4
|Oct mean C = 26.2
|Nov mean C = 23.3
|Dec mean C = 20.2
|year mean C = 
|Jan low C = 13.4
|Feb low C = 16.3
|Mar low C = 18.5
|Apr low C = 20.1
|May low C = 21.7
|Jun low C = 23.1
|Jul low C = 23.7
|Aug low C = 23.8
|Sep low C = 23.1
|Oct low C = 21.1
|Nov low C = 17.9
|Dec low C = 15.0
|year low C = 
|Jan record high C = 33.0
|Feb record high C = 33.8
|Mar record high C = 38.0
|Apr record high C = 37.0
|May record high C = 39.0
|Jun record high C = 38.0
|Jul record high C = 39.0
|Aug record high C = 40.0
|Sep record high C = 39.0
|Oct record high C = 38.0
|Nov record high C = 36.9
|Dec record high C = 35.0
|Jan record low C = 5.0
|Feb record low C = 9.0
|Mar record low C = 12.0
|Apr record low C = 14.3
|May record low C = 15.1
|Jun record low C = 16.0
|Jul record low C = 17.0
|Aug record low C = 19.0
|Sep record low C = 17.0
|Oct record low C = 14.0
|Nov record low C = 10.0
|Dec record low C = 7.5
|Jan rain mm = 17.3
|Feb rain mm = 31.1
|Mar rain mm = 80.2
|Apr rain mm = 216.5
|May rain mm = 380.3
|Jun rain mm = 807.2
|Jul rain mm = 962.6
|Aug rain mm = 779.1
|Sep rain mm = 492.6
|Oct rain mm = 162.9
|Nov rain mm = 13.2
|Dec rain mm = 10.4
|rain colour = green
|year rain mm = 
|Jan humidity = 72.4
|Feb humidity = 71.3
|Mar humidity = 70.0
|Apr humidity = 74.7
|May humidity = 80.1
|Jun humidity = 83.8
|Jul humidity = 88.5
|Aug humidity = 87.1
|Sep humidity = 84.4
|Oct humidity = 75.6
|Nov humidity = 70.7
|Dec humidity = 72.4
|source 1 = National Center for Hydrology and Meteorology<ref>{{cite web
| url = https://www.nchm.gov.bt/attachment/ckfinder/userfiles/files/Climate%20Data%20Book%20of%20Bhutan%2C%202018.pdf
| title = Climate Data Book of Bhutan, 2018
| publisher = [[National Center for Hydrology and Meteorology]]
| accessdate = 13 July 2021
}}</ref>
}}

==Glaciers==
{{main|Glaciers of Bhutan}}
[[Glacier]]s in northern Bhutan, which covered about 10 per cent of the total surface area in the 1980s, are an important renewable source of water for Bhutan's rivers. Fed by fresh snow each winter and slow melting in the summer, the glaciers bring millions of litres of fresh water to Bhutan and downriver areas each year. Glacial melt adds to [[monsoon]]-swollen rivers, however, also contributes to flooding. Where glacial movement temporary blocks riverflows, downstream areas may be threatened by [[glacial lake outburst flood]]s (GLOFs), also called ''[[jökulhlaup]]s''.<ref name=CSg>{{Country study|author=Robert L. Worden |country=Bhutan |section=Glaciers |abbr=bt |editor=Andrea Matles Savada |date=September 1991 |pd=yes}}</ref>

Bhutan's glaciers are melting. A 2008 [[United Nations]] report suggested that due to rising temperatures, glaciers in Bhutan were retreating at a rate of {{Convert|30-40|m|4=-1}} per year, poised to make many lakes burst their banks and send millions of gallons of floodwater downstream. This among many other [[environmental issues in Bhutan|climate-related issues]] identified in the report prompted the regional association of government ministers to establish the Southeast Asia Regional Health Emergency Fund in [[Thimphu]] in September 2007.<ref name=BO1/> Similarly, the member nations of [[South Asian Association for Regional Cooperation]] (SAARC) adopted bilateral agreements including measures on climate change and glaciers at its summit in April 2010.<ref>{{cite web |url=http://www.bhutanobserver.bt/summit-declaration-ready-for-adoption/ |title=Summit declaration ready for adoption |first=Sonam |last=Pelden |date=10 April 2010 |publisher=Bhutan Observer online |access-date=27 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110120041637/http://www.bhutanobserver.bt/summit-declaration-ready-for-adoption/ |archive-date=20 January 2011 }}</ref>

The 2008 UN report also indicated Himalayan glaciers would melt within 25 years,<ref name=BO2>{{cite web |url=http://www.bhutanobserver.bt/himalayan-glaciers-not-retreating-says-new-report/ |title=Himalayan glaciers not retreating, says new report |first=Namgay |last=Tshering |date=29 January 2011 |publisher=Bhutan Observer online |access-date=27 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110207213137/http://www.bhutanobserver.bt/himalayan-glaciers-not-retreating-says-new-report/ |archive-date=7 February 2011 }}</ref> however [[Prime Minister of Bhutan|Prime Minister]] [[Jigme Thinley]] expressed a more dim outlook in a press conference in late March 2010, stating, "Our glaciers are withdrawing very fast and we have reasons to worry that they may in fact disappear not in 2035, but even earlier."<ref name=BO4>{{cite web |url=http://www.bhutanobserver.bt/looking-beyond-hydropower/ |title=Looking beyond hydropower |date=2 April 2010 |first=Sonam |last=Pelden |publisher=Bhutan Observer online |access-date=27 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111003050052/http://www.bhutanobserver.bt/looking-beyond-hydropower/ |archive-date=3 October 2011 }}</ref>

The new inventory "Bhutan Glacial Inventory 2018" includes 700 glaciers covering total area of {{Convert|629.55|±|0.02|km2|abbr=on}} in the northern frontiers of Bhutan. Glacier area covers 1.64% of the total land cover in Bhutan.<ref>{{Cite web|url=http://www.nchm.gov.bt/home/pageMenu/32|title=National Center for Hydrology and Meteorology|website=nchm.gov.bt|access-date=2019-07-28}}</ref>

==Lakes==
{{main|Lakes of Bhutan}}
Bhutan is home to at least 59 natural mountain lakes as well as some 2,674 [[glacial lake]]s; about 25 of these glacial lakes are potential [[GLOF]] hazards.<ref name=BO1>{{cite web |url=http://www.bhutanobserver.bt/managing-health-disaster/ |title=Managing health disaster |date=19 January 2008 |first=Badan |last=Tirwa |publisher=Bhutan Observer online |location=[[Thimphu]] |access-date=27 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110120120112/http://www.bhutanobserver.bt/managing-health-disaster/ |archive-date=20 January 2011 }}</ref><ref name=Thorthormi>{{cite web |url=http://www.bhutanobserver.bt/thorthormi-water-level-brought-down-43-cm/ |title=Thorthormi water level brought down 43&nbsp;cm |first=Sonam |last=Pelden |publisher=Bhutan Observer online |date=3 September 2010 |access-date=27 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110119113517/http://www.bhutanobserver.bt/thorthormi-water-level-brought-down-43-cm/ |archive-date=19 January 2011 }}</ref>

Non-glacial lakes in Bhutan cover a total of about {{convert|4250|ha|sqmi}}. Most are located above an altitude of {{convert|3500|m|ft}}, and most have no permanent human settlements nearby, though many are used for grazing yaks and may have scattered temporary settlements.<ref name=Bisht>{{cite book|title=International Encyclopaedia of Himalayas|first=Ramesh Chandra |last=Bisht |date=January 2008 |publisher=Mittal Publications |isbn=978-81-8324-265-3 |pages=34–5 |url=https://books.google.com/books?id=XWblUfYqGK4C}}</ref><ref name=FAO1>{{cite web|url=http://www.fao.org/docrep/field/003/L8853E/L8853E02.htm |publisher=United Nations [[Food and Agriculture Organization]] |title=Survey of the Waters of Bhutan – Physiography and Fisheries Potential |date=December 1978 |access-date=26 November 2011}}</ref>

==River systems==
{{further|List of rivers of Bhutan}}
[[File:Glacial lakes, Bhutan.jpg|thumb|right|300px|This image shows the termini of the [[glaciers in Bhutan|glaciers in the Bhutan-Himalaya]]. [[Glacial lake]]s have been rapidly forming on the surface of the debris-covered glaciers in this region during the last few decades.]]

Bhutan has four major river systems: the [[Drangme Chhu]]; the [[Puna Tsang Chhu]], also called the [[Sankosh]]; the [[Raidak River|Wang Chhu]]; and the [[Amo Chhu]]. Each flows swiftly out of the [[Himalaya]]s, southerly through the [[Dooars]] to join the [[Brahmaputra River]] in India, and thence through [[Bangladesh]] where the Brahmaputra (or [[Jamuna River (Bangladesh)|Jamuna]] in Bangladesh) joins the mighty [[Ganges]] (or Padma in Bangladesh) to flow into the [[Bay of Bengal]]. The largest river system, the Drangme Chhu, flows southwesterly from India's state of [[Arunachal Pradesh]] and has three major branches: the Drangme Chhu, [[Mangde Chhu]], and [[Bumthang River|Bumthang Chhu]]. These branches form the Drangme Chhu basin, which spreads over most of eastern Bhutan and drains the [[Tongsa]] and [[Bumthang Valley|Bumthang]] valleys. In the Duars, where eight tributaries join it, the Drangme Chhu is called the [[Manas River|Manas Chhu]]. The {{Convert|320|km|4=-long|adj=mid}} Puna Tsang Chhu rises in northwestern Bhutan as the [[Mo Chhu]] and [[Pho Chhu]], which are fed by the snows from the Great Himalayan Range. They flow southerly to [[Punakha]], where they join to form the Puna Tsang Chhu, which flows southerly into India's state of [[West Bengal]]. The tributaries of the {{Convert|370|km|4=-long|adj=mid}} Wang Chhu rise in Tibet. The Wang Chhu itself flows southeasterly through west-central Bhutan, drains the Ha, Paro, and Thimphu valleys, and continues into the Duars, where it enters West Bengal as the [[Raigye Chhu]]. The smallest river system, the [[Torsa Chhu]], known as the Amo Chhu in its northern reaches, also flows out of Tibet into the [[Chumbi Valley]] and swiftly through western Bhutan before broadening near [[Phuntsholing]] and then flowing into India.<ref name=CSr>{{Country study|author=Robert L. Worden |country=Bhutan |section=River Systems |abbr=bt |editor=Andrea Matles Savada |date=September 1991 |pd=yes}}</ref>

==Valleys==
{{main|Valleys of Bhutan}}

[[Valleys of Bhutan|Bhutan's valleys]] are carved into the Himalaya by its [[list of rivers of Bhutan|rivers]], fed by glacial melt and monsoon rains. Much of the Bhutanese population is concentrated in valleys and lowlands, separated by rugged southward spurs of the Inner Himalaya.<ref name=CS1>{{country study|country=Bhutan |abbr=bt |editor=Savada, Andrea Matles |date=1991 |section=The Land |author=Worden, Robert L. |pd=yes}}</ref><ref name=CS2>{{country study|country=Bhutan |abbr=bt |editor=Savada, Andrea Matles |date=1991 |section=Population – Size, Structure, and Settlement Patterns |author=Worden, Robert L. |pd=yes}}</ref><ref>{{cite book|title=Sikhim & Bhutan: Twenty-One Years on the North-East Frontier, 1887-1908 |first=John Claude |last=White |publisher=E. Arnold |year=1909 |pages=[https://archive.org/details/in.ernet.dli.2015.279230/page/n21 3]–6 |url=https://archive.org/details/in.ernet.dli.2015.279230 |access-date=15 October 2011}}</ref><ref name=BWK>{{cite book|url=https://books.google.com/books?id=sHAnAtNrUQoC |title=Bhutan: Ways of Knowing |first1=Frank |last1=Rennie |first2=Robin |last2=Mason |publisher=IAP |page=58 |year=2008 |isbn=978-1-59311-734-4 |access-date=10 August 2011}}</ref><ref>{{cite book |title=Bhutan Foreign Policy and Government Guide |volume=20 |series=World Foreign Policy and Government Library |author=Global Investment and Business Center |publisher=International Business Publications |year=2000 |isbn=0-7397-3719-8 |url=https://books.google.com/books?id=_EWuvGysPSIC |access-date=15 October 2011 }}{{Dead link|date=May 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref name=LP>{{cite book|title=Bhutan |first1=Lindsay |last1=Brown |first2=Stan |last2=Armington |edition=3 |publisher=[[Lonely Planet]] |year=2007 |isbn=978-1-74059-529-2 |pages=62, 105, 108, 113 |url=https://books.google.com/books?id=s-L8NUlW_QgC |access-date=25 November 2011}}</ref>{{rp|72, 84, 91}} Despite modernization and development of [[transport in Bhutan]], including a national highway system, travel from one valley to the next remains difficult.<ref name=CS3>{{country study|country=Bhutan |abbr=bt |editor=Savada, Andrea Matles |date=1991 |section=Transportation and Communications – Roads |author=Worden, Robert L. |pd=yes}}</ref> Western valleys are bound to the east by the [[Black Mountains (Bhutan)|Black Mountains]] in central Bhutan, which form a watershed between two major river systems, the [[Mo Chhu]] ([[Sankosh River]]) and the [[Drangme Chhu]]. Central valleys are separated from the east by the [[Mountains of Bhutan|Donga Range]].<ref name=CS1/><ref name=CS4>{{country study|country=Bhutan |abbr=bt |editor=Savada, Andrea Matles |date=1991 |section=River Systems |author=Worden, Robert L. |pd=yes}}</ref><ref>{{cite book|title=Encyclopaedia of Women in South Asia: Bhutan |volume=7 |first=Bachchan |last=Kumar |publisher=Gyan |year=2004 |isbn=81-7835-194-3 |page=20 |url=https://books.google.com/books?id=89gPZeNyFyIC |access-date=15 October 2011}}</ref> The more isolated mountain valleys protect several tiny, distinct cultural and [[languages of Bhutan|linguistic groups]].<ref name=LP2>{{cite book |title=Bhutan |series=Country Guides |publisher=[[Lonely Planet]] |first1=Lindsay |last1=Brown |first2=Stan |last2=Armington |edition=3 |year=2007 |isbn=978-1-74059-529-2 |url=http://www.lonelyplanet.com/shop_pickandmix/previews/bhutan-3-eastern-bhutan-preview.pdf |pages=182–183 |access-date=15 October 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110607073544/http://www.lonelyplanet.com/shop_pickandmix/previews/bhutan-3-eastern-bhutan-preview.pdf |archive-date=7 June 2011 }}</ref>

== Forests ==
In Bhutan [[forest cover]] is around 71% of the total land area, equivalent to 2,725,080 hectares (ha) of forest in 2020, up from 2,506,720 hectares (ha) in 1990. In 2020, naturally regenerating forest covered 2,704,260 hectares (ha) and planted forest covered 20,820 hectares (ha). Of the naturally regenerating forest 15% was reported to be [[primary forest]] (consisting of native tree species with no clearly visible indications of human activity) and around 41% of the forest area was found within protected areas. For the year 2015, 100% of the forest area was reported to be under [[State ownership|public ownership]].<ref>{{Cite book |url=https://openknowledge.fao.org/server/api/core/bitstreams/a6e225da-4a31-4e06-818d-ca3aeadfd635/content |title=Terms and Definitions FRA 2025 Forest Resources Assessment, Working Paper 194 |publisher=Food and Agriculture Organization of the United Nations |year=2023}}</ref><ref>{{Cite web |title=Global Forest Resources Assessment 2020, Bhutan |url=https://fra-data.fao.org/assessments/fra/2020/BTN/home/overview |website=Food Agriculture Organization of the United Nations}}</ref>

==References==
{{Reflist}}

{{Bhutan topics}}
{{GeoSouthAsia}}
{{Geography of Asia}}
{{Asia topic|Climate of}}

{{Coord|27|30|N|90|30|E|type:country|display=title}}
{{Use British English|date=August 2010}}

[[Category:Geography of Bhutan| ]]

[[bn:ভুটান#ভূগোল]]