Geography of Bhutan

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|+<big><big>Bhutan</big></big>

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| Continent || Asia

| Subregion || South Asia

| Geographic coordinates ||

| Area  - Total  - Water

| Ranked 137th (landlocked)

| Coastline ||

| Land boundaries ||

| Countries bordered || China , India

| Highest point || Gangkhar Puensum,

| Lowest point || Drangme Chhu, Gewogs are in turn divided into numerous thromdes (municipalities) for administration.

Physical geography

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 ; the highest point in Bhutan is Gangkhar Puensum, which has the distinction of being the highest unclimbed mountain in the world, at .

Temperatures vary according to elevation. Temperatures in Thimphu, located at above sea level in west-central Bhutan, range from approximately during the monsoon season of June through September but drop to between about 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 year-round, although temperatures sometimes reach in the valleys during the summer.

Glaciers

Glaciers 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 floods (GLOFs), also called jökulhlaups.

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 per year, poised to make many lakes burst their banks and send millions of gallons of floodwater downstream. This among many other 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.

The 2008 UN report also indicated Himalayan glaciers would melt within 25 years, however 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."

The new inventory "Bhutan Glacial Inventory 2018" includes 700 glaciers covering total area of in the northern frontiers of Bhutan. Glacier area covers 1.64% of the total land cover in Bhutan.

Lakes

Bhutan is home to at least 59 natural mountain lakes as well as some 2,674 glacial lakes; about 25 of these glacial lakes are potential GLOF hazards.

Non-glacial lakes in Bhutan cover a total of about . Most are located above an altitude of , and most have no permanent human settlements nearby, though many are used for grazing yaks and may have scattered temporary settlements.

River systems

thumb|right|300px|This image shows the termini of the [[glaciers in Bhutan|glaciers in the Bhutan-Himalaya. Glacial lakes 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 Wang Chhu; and the Amo Chhu. Each flows swiftly out of the Himalayas, southerly through the Dooars to join the Brahmaputra River in India, and thence through Bangladesh where the Brahmaputra (or 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 Chhu. These branches form the Drangme Chhu basin, which spreads over most of eastern Bhutan and drains the Tongsa and Bumthang valleys. In the Duars, where eight tributaries join it, the Drangme Chhu is called the Manas Chhu. The 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 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.

Valleys

Bhutan's valleys are carved into the Himalaya by its 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. Despite modernization and development of transport in Bhutan, including a national highway system, travel from one valley to the next remains difficult. Western valleys are bound to the east by the 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 Donga Range. The more isolated mountain valleys protect several tiny, distinct cultural and linguistic groups.

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 public ownership.

Rangeland

alt=Rangeland distribution across Bhutan, showing the uneven spatial distribution of herbaceous, shrub and bush, and mixed rangeland types among the country’s twenty districts|thumb|National rangeland map of BhutanNational rangeland map of Bhutan|402x402px

According to the most recent study on rangeland changes, rangelands in Bhutan are semi-natural ecosystems made up of grasslands, shrublands, and mixed vegetation, mostly found in the montane and alpine regions. They are considered essential for pastoral livelihoods, biodiversity conservation, and the functioning of high-mountain ecosystems. A nationwide assessment estimated that rangelands cover about 9,307 km² of Bhutan’s total land area. This major includes 3,451 km² of herbaceous rangeland, 3,546 km² of shrub and bush rangeland, and 2,310 km² of mixed rangeland. Large rangeland areas occur in districts such as Gasa, Wangdue Phodrang, Bumthang, Thimphu, Paro, and Haa. The ICIMOD study on rangeland area and vegetation change was conducted using a combination of remote sensing techniques and field surveys, which ensures data reliability and comparability. Analysis of vegetation change from 2013 to 2024 shows that most rangelands remain stable. Some areas show increased vegetation greenness, while others show decline, especially in shrub-dominated rangelands. An increase in greenness does not always mean improved rangeland condition, as shrub expansion and invasive species can reduce forage quality. The findings also show that rainfall alone does not determine rangeland condition. Rangeland dynamics are often controlled by a combination of climate variability, topography, grazing pressure, and land-cover change, demonstrating the need for integrated rangeland management in Bhutan.

References

bn:ভুটান#ভূগোল