Editing Geography of Bhutan (section)

==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>