The Lhonak River is a tributary of the
Teesta River
Teesta River is a long river that rises in the Pauhunri Mountain of eastern Himalayas, flows through the Indian states of Sikkim and West Bengal and subsequently enters Bangladesh through Rangpur division. In Bangladesh, it merges with Jamu ...
in the
Indian state
India is a federal union comprising 28 states and 8 union territories, for a total of 36 subnational entities. The states and union territories are further subdivided into 800 districts and smaller administrative divisions by the respe ...
of
Sikkim
Sikkim ( ; ) is a States and union territories of India, state in northeastern India. It borders the Tibet Autonomous Region of China in the north and northeast, Bhutan in the east, Koshi Province of Nepal in the west, and West Bengal in the ...
.
Course
The Lhonak originates as a small stream from a glacier in the snowy wastes of northern Sikkim. It generally flows south till it joins the Teesta. The main
Himalayan wall with its high snow-clad peaks forms the northern boundary of the catchment. Small glaciers or tongues of perpetual ice descend from the depressions between the ridges into the valleys. They give birth to small streams which join the main channel of the Lhonak. The upper course is along an ancient glacial valley. While the middle and lower courses have been carved by both the action of ice and running water, the side valleys are formed by melt-ice and open into the main valley. No vegetation is found in higher reaches. Alpine pastures occur near the
snow line
The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...
.
Subalpine
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
and
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...
forests are found at lower elevations. Human habitation in the Lhomak valley is very sparse. It is visited by
graziers.
[
]
Lake
Lake Lhonak was considered a dangerous lake, which may outburst. Central Water Commission carried out the study and the Department of Science and Technology carried out the bathymetric survey to assess its volume and possible danger of outburst.
Lhonak valley
The Lhonak Valley is a grassland in the exposed river valley of Goma Chu in northwest Sikkim, with boggy marshes, glacial lakes, barren scree slopes and glaciers. Goma Chu rises in North and South Lhonak glaciers and runs across the valley to join Zema Chu, a glacier at the southern end of the valley, as is Green Lake.
References
Rivers of Sikkim
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