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The Mighty Lohit River: India’s Easternmost Tributary of the Brahmaputra
The Lohit River- Origin and Course
The Lohit River originates in eastern Tibet where it is known as the Zayu River. It begins high up in the Zayal Chu mountain range, fed by snowmelt and glaciers. The river initially flows in a southwest direction through the rugged mountains.
In this article, the UCN Team provides a detailed analysis, presenting key information on the Lohit River.
Two main tributaries merge to form the Lohit – the Kangri Karpo Chu and the Zayul Chu. The confluence of these two rivers marks the official beginning of the Lohit. From here, the river takes a sharp turn to the southeast.
The Lohit then flows for around 200 km through the thickly forested Mishmi Hills in the Indian state of Arunachal Pradesh. This stretch of the river passes through deep gorges and has very turbulent waters. Several tributaries join the Lohit in the Mishmi Hills, increasing its volume significantly.
At the end of its course through Arunachal Pradesh, the Lohit meets the Siang River. The point where these two large rivers merge forms the beginning of the mighty Brahmaputra River. From here, the Brahmaputra flows southwest through the Assam valley into Bangladesh, where it is known as the Jamuna River before meeting the Ganges.
Features
The Lohit River has a distinct reddish color caused by the large amounts of lateritic soil it carries downstream. The river collects this reddish soil as it flows through the Mishmi Hills which have large deposits of laterite rocks.
Near the end of its course, the Lohit enters the Assam plains close to Kibithu – India’s easternmost permanently inhabited settlement. The Lohit is navigable by small boats up to Kibithu. From here, the river winds lazily across the flat plains of Assam.
A key landmark along the Lohit is the mighty Dhola-Sadiya Bridge, which crosses the river near the town of Roing. This bridge connects the states of Assam and Arunachal Pradesh. With a total length of 9.15 km, it is the longest bridge in India.
The Lohit valley has strategic importance for India and is used extensively by the Indian Army for transport, expeditions and adventure training. The challenging terrain allows troops to hone their skills.
The Lohit holds the distinction of being the farthest east tributary of the Brahmaputra River. It meets the Siang River which then becomes the Brahmaputra – one of the largest rivers in India.
Major tributaries of the Lohit River
| Tributary | Description |
| Kangri Karpo Chu | One of the two main tributaries that form the Lohit in Tibet. It merges with the Zayul Chu to form the Lohit. |
| Zayul Chu | Major tributary originating in Tibet that merges with the Kangri Karpo Chu to form the Lohit. |
| Tidding River | Large tributary joining the Lohit in India. Has its origins in moraine fields in Tibet. |
| Dau River | Tributary joining the Lohit in India. Rises from springs and lakes. |
| Dalai River | Snow-fed tributary meeting the Lohit in India. Drains higher elevation regions. |
| Tirap River | Tributary joining the Lohit in India. Has thick forests in its upper catchment. |
| Lashi River | Tributary that meets the Lohit upstream of Tezu town. |
| Digaru River | Tributary joining the Lohit downstream of Tezu. Drains forested slopes. |
| Siang River | Major river that merges with the Lohit to form the Brahmaputra. |
Importance
Here is the text with some additional names and data from the provided files:
The Lohit is a major river in India’s Northeast region. It is an important tributary of the Brahmaputra River Basin which is a lifeline for the states of Arunachal Pradesh and Assam.
The river is a critical water source for irrigation and drinking purposes in its basin area. Several towns along the river like Tezu, Roing, and Kibithu depend on it for their water supply. The Lohit’s water allows cultivation of crops like rice, oilseeds, pulses and horticultural produce.
The Lohit basin harbors rich biodiversity of flora and fauna. Its thick sub-tropical forests like the Kamlang Wildlife Sanctuary are home to endangered species like tigers, elephants, leopards, hoolock gibbons and black necked storks.
Several hydroelectric projects like the Lower Demwe Hydro Electric Project have been proposed along the Lohit and its tributaries like the Tidding River. The river has immense potential to produce hydroelectric power which can meet the increasing energy demands of the region.
The natural beauty and biological wealth of the Lohit valley provide unique tourism opportunities for adventure sports like river rafting, trekking and angling. However, tourism needs to be promoted responsibly keeping local sensitivities in mind.
In short, the Lohit which rises from over 6,000 m in Tibet to flow into the Brahmaputra is indispensable for the economy and ecology of Arunachal Pradesh and downstream areas. It is a vital resource that needs to be managed in a sustainable manner.
Threats
The Lohit faces several threats that can impact its natural state and flow.
Upstream deforestation in the Zayal Chu mountains and Mishmi Hills has led to severe soil erosion in the catchment area. Tree cutting reduces interception and accelerates surface runoff, causing heavy siltation in the river. This is evident in the river’s reddish-brown color.
Climate change is causing receding of glaciers that feed the Lohit. Several studies warn that glacier retreat will reduce dry season flows in the coming decades. Rising temperatures may initially increase glacial runoff but could eventually decrease the Lohit’s water volume.
The growing population in Arunachal Pradesh has led to pollution concerns, especially near towns along the river’s banks. Raw sewage and garbage dumping compromises water quality. Agrochemical runoff from fields also ends up in the river, affecting aquatic ecosystems.
Several dam projects have been proposed on the Lohit and its tributaries. Local communities fear this could alter the river’s natural flow cycle and impact the riparian environment. Proper environmental impact assessments are crucial if dams are constructed.
Clearly, a sustainable management strategy is urgently required to address these challenges and conserve the Lohit River basin.
Conservation Efforts
Some steps have been taken to protect and wisely manage the Lohit River basin:
Several reserve forests have been designated along the course of the Lohit river, mostly in the upper reaches and tributaries. Some notable ones are Sessa Orchid Sanctuary, Mehao Wildlife Sanctuary and Kamlang Wildlife Sanctuary. Though logging is banned here, protection against encroachment and grazing needs to be strengthened.
NGOs like Aranyak and River-Rally have launched awareness campaigns in the Lohit valley. They conduct nature education programs in schools and train youth as conservation leaders.
Sustainable tourism activities like Fishing, bird-watching and community homestays are being promoted with local participation. This provides livelihoods while giving tourists a chance to appreciate the Lohit’s natural riches responsibly.
Final Thoughts
In the UCN team’s careful evaluation, a long-term vision is required that finds a balance between development and conservation of the Lohit river basin. The Lohit’s resources can be tapped without compromising its ecological integrity. Local voices need to be heard while making policies for hydropower, roads, mines, etc. in the region.
With collective will, it is possible to use the Lohit judiciously while also keeping its lifeline flowing for future generations through integrated planning and participatory management.
FAQ
Where does the Lohit River originate?
The Lohit River originates in eastern Tibet where it is known as the Zayu River. It begins from the Zayal Chu mountain range, which lies at a high elevation.
What are the major tributaries of the Lohit River?
The two main tributaries that form the Lohit are the Kangri Karpo Chu and Zayul Chu rivers. Other important tributaries that join the Lohit in India are the Tidding, Dau, Dalai, Tirap, and Lashi rivers.
Which river does the Lohit merge into?
The Lohit River merges with the Siang River, which then becomes the mighty Brahmaputra River. The confluence of the Lohit and Siang rivers takes place in Arunachal Pradesh.
What causes the reddish color of the Lohit River?
The reddish color of the Lohit River comes from the large amounts of lateritic soil it carries. Laterite rocks are found extensively in the Mishmi Hills through which the Lohit flows in India.
