Regional Analysis

Brahmaputra River Tourism Development

The Brahmaputra is a major international river covering a drainage area of 580,000 sq. km. 50.5 % of which lie in China, 33.6 % in India, 8.1 % in Bangladesh and 7.8 % in Bhutan. Its basin in India is shared by Arunachal Pradesh 41.88%, Assam 36.33%, Nagaland 5.57%, Meghalaya 6.10%, Sikkim 3.75% and West Bengal 6.47%. Two rivers, the Dibang (also known as Siang) and the Lohit, join the upper course of Brahmaputra. While flowing 2,880 kilometres through China, Tibet, India and Bangladesh, the river is joined by nearly 22 major tributaries in Tibet, 33 in India and 3 in Bangladesh. Brahmputra is a major river of Central and South Asia. For most of its length, the river serves as an important inland waterway; it is not, however, navigable between the mountains of Tibet and the plains of India.

Based on the lithology and climate, the Brahmaputra basin is divided into five sub-basins: (i) Tibet, (ii) Eastern Syntaxis, (iii) Eastern drainage/Mishmi Hills, (iv) Himalaya and (v) Southern drainage

In India, it covers a region of 109.84 million hectares or one third of the size of the country.

7. 
   Characteristics of River Brahmaputra
   

1. 
   

   Hydropower potential	About 41 % of the country’s total
   Potential developed so far	Only about 3 %
   Irrigation potential	4.26 million hectare
   Present coverage of irrigation	0.85 Million hectare (20 %of existing potential against the national average of 56.4%)
   Ground water potential	Very high in valley areas (at shallow depth)
   Potential developed so far	4.3% (against the national average of 32%)
   Source: Flood Control Department, Assam

   The hydrological characteristics of the Brahmaputra valley is dominated by intense powerful monsoon rainfall region of the eastern Himalayas, the freeze–thaw cycle of Himalayan snow, and the immensely dynamic fluvial processes of the river and its tributaries.
   
2. 
   is among the largest, most flood prone and most unstable rivers in the world
   

3. 
   Barak basin has its drainage area in India (Meghalaya, Manipur, Mizoram, Nagaland, Tripura and Assam), Myanmar & Banagladesh. The drainage area of the basin in India is 26,123sq. km and forms part of main Brahmaputra basin.
   
4. 
   The Brahmaputra is the 4^th largest river in terms of average discharge at the mouth, with a flow of 19,839 m3 s–1, and second in terms of sediment transport per unit drainage area in the world. It is only after Amazon, Congo, and Yangtze.
   
5. 
   Dibang and Lohit in Arunachal Pradesh is thegeographical region where the Brahmaputra develops 400 million tons of silt & are deposited and transported every year.
   
6. 
   Mid march and Mid April are a comparatively dry period when the level of the river is at its lowest and an extended river bank facilities safe bathing
   

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  Most of the rivers coming down from the Himalayas and joining the Brahmaputra have vast catchment areas
  
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  The rivers are characterized by very steep gradients in the mountains and flow rapidly carrying heavy load of silt; while descending on the plains they flatten with sharp sagging of gradients, resulting in heavy siltation of river beds in the aftermath of the floods.
  
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  The Brahmaputra River has a mean gradient of only about 1.5m per km over a distance of around 650km between Kobo where the confluence is, and Dhubri where it leaves Assam and enters Bangladesh. The gradients are:
  

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  Between Kobo and Dibrugarh- the bed slopes 0.62m/km
  
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  Between Dibrugarh and Neamati the bed slopes 0.17m/km
  
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  Between Neamati and Guwahati the bed slopes 0.13m/km
  
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  Between Guwahati and Dhubri the bed slopes 094m/km
  

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  Bring flash floods because of short distance between their source in the hills and the confluence
  
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  rivers characterized by very steep slope and shallow braided channels
  
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  have coarse sandy beds and carry heavy silt
  

7. 
   The South Bank tributaries originate in hills of Nagaland, North Cachar, Karbi Anglong and Meghalaya and flow from south to north and coverage into the Brahmputra. The river has flatter slope, deep meandering channels almost from the foothills, beds and banks of fine alluvial soil and a comparatively low silt charge. The banks and beds of all southern rivers are composed of clay of various colors with a small quantity of coarse sands. These are also rainfed.
   
8. 
   57 tributaries on its north bank and 33 on its south feed the Brahmaputra on its course through the valley.
   
9. 
   There are Natural Constrictions at Various Locations along the Brahmaputra. The Constrictions are at:
   

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  Murkonselek - 4.8 km
  
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  Disangmukh - 5.1 km
  
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  Dhanshirimukh - 4.4 km
  
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  Tezpur - 3.6 km
  
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  Pandu - 1.2 km
  
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  Soalkuchi - 2.4 km
  
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  Pancharatna - 2.4 km
  

The Brahmaputra River and the 33 major tributaries joining it in Assam, including the main trans-Himalayan tributaries of Subansiri, Jia Bharali, and Manas, carry about 30% of the country’s total surface water. Surface water bodies covering about 8,251 square kilometers (km2) account for 10.5% of the geographical area of the state. Of these, the river systems, including waterlogged areas, occupy 6,503 km2. The annual surface water availability is more than 53 million hectare-meters. Brahmaputra valley in Assam has 3,513 wetlands, covering 1,012.3 km2. Groundwater is also plentiful at shallow depth in the valley; utilizable groundwater is estimated to exceed 2 million hectare-meters.

1. 
   Two geological factors are dominant in determining the morphological character of the Brahmaputra River in Assam. First, the Himalayan ranges to the north, from which the right bank tributaries emerge, are uplifting at a rate in the order of 1 meter per century. Secondly, the whole region is subject to frequent seismic movements and periodic major earthquakes. The Assam earthquakes of 1897 and 1950, both of magnitude 8.7 on the Richter scale, were among the largest within historical experience anywhere in the world.
   
2. 
   The Brahmaputra River, flowing through Assam from east to west over a length of approximately 650 kilometers.
   
3. 
   The characteristics of the river itself are very similar in Assam and Bangladesh. In Assam, however, the river lies in a well-defined alluvial valley ranging from 40 to 100 kilometers in width and bounded by mountains and hills, whereas in Bangladesh the environment is more deltaic in nature.
   
4. 
   Brahmaputra River in Assam is almost 700 k.m. long with more than 100 tributaries. Brahmaputra, the major natural feature in Guwahati, has total length of 28.67 km in Guwahati and total area 49 sq.km. The Assam basin has a length of about 1540km in EW direction and maximum width of 682 km in NS direction. The State of Assam lies in the middle reach of the river Brahmaputra and Barak.
   

The entire length of the river through Assam has a multichannel character. Under low-flow conditions most reaches show three to six channels separated by islands and bars, a type of planform generally known as braided

Through more than 90 percent of the length through Assam, the land adjacent to the river consists of low-level floodplain deposits of fine sand and silt, with very little resistance to erosion.

Sediments in the valley through Assam are predominantly either floodplain deposits created by the Brahmaputra itself, or alluvial fan deposits created by tributaries emerging from the mountains and hills onto the floodplain. The material of the riverbed consists mainly of fine and medium sand, and the floodplain deposits of silt and fine sand.

Because sediment tends to accumulate in and adjacent to the river channel system, the center of the valley is apparently higher than the outer margins of the floodplain – that is, the river is somewhat perched. Such a feature tends to encourage extensive lateral shifting of the channel system in major flood or earthquake events. In the 18th century, major shifts of the Brahmaputra occurred in both Assam and Bangladesh. The present Jamuna River in Bangladesh, which is the downstream extension of the Brahmaputra in Assam, has small distributaries known as the Old Brahmaputra, which represents a former course of the main river that is now largely filled with sediment.

Along its course through Assam, the gradient of the Brahmaputra reduces from roughly 0.2 to 0.1 meters per kilometer. Such a low gradient is characteristic of large alluvial rivers with sandy beds. Overall flattening of gradient in a downstream direction is typical of rivers in more or less uniform environments.

According to a longitudinal profile supplied by the Assam Water Resources Department, flood heights above tops of banks vary greatly from reach to reach. At some locations the 100-year flood level is shown as slightly below the north bank, whereas at other places it is 10 meters or more above it. At least on the north side, locations most susceptible to deep flooding appear to be mainly in the upstream two-thirds of the length, east of Pandu and Guwahati.

The long-term average discharge of the Brahmaputra increases through Assam from about 8,500 to 17,000 cubic meters per second. The largest average monthly discharges at Pandu, about two-thirds of the river distance through Assam, are around 36,000 cubic meters per second for the months of June and July

5. 
   The Brahmaputra valley in Assam represents a tectonose dimentary province 720 km long and 80 to 90 km wide, with elevation ranging from 120 m at Kobo in the extreme east through 50.5 m at Guwahati to 28.45 m at Dhubri in the extreme west1. The channel of the river itself occupies about one-tenth of the valley, with over 40% of its area under cultivation. The Brahmaputra valley in Assam is the home of more than 15 million people. In Assam, the river flows in a highly braided channel characterized by numerous mid-channel bars and islands.
   
6. 
   Dibru ghat is near Dibrugarh town and 500 km upstream of Guwahati. Until 1967, the ghat was connected by rail to the town. Until this time, a company named River Steam Navigation Company operated steamer services from Kolkata to Dibrugarh. The shipping company also shut down its operations, saying that its vessels could not traverse the channels because of heavy silting. The rail line was abandoned and there are local ferry services which ply from one side of the river to the other (Sonari ghat). In addition, there is a long distance ferry (IWT of Assam) that takes passengers and goods between Dibrugarh and Oriamghat, near Pasighat in Arunachal Pradesh, a 130-kilometre-journey which takes nine hours to travel upstream.
   

7. 
   In the vicinity of Majuli Island, about 25 percent of the total river length from the upper end, the Brahmaputra has migrated southward by at least 25 kilometers since about 250 years ago. This location is believed to be a special case, and the actual period over which the shift took place is not stated.
   

RIVER TOURISM DEVELOPMENT CONCERNS:

Tourism development of Brahmaputra River is possible if the following conditions are taken into account:

1. 
   Erosion:
   

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  The activity of erosion is much more pronounced near Jorhat–Majuli areas, and continues for 50 km up to Kumargaon. The area around Kaziranga National Park also witnessed major erosion activity near Sohola Bil up to Dipholumukh. In this area, a total of 83.23 km2 was eroded away from the main mass till 1975
  
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  The banks on both sides of the Brahmaputra from Orang Reserve Forest to Haloukonda Bil are subjected to significant erosion.
  
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  The erosion was much more pronounced on the northern bank of the river than the southern bank for the period 1914–75.
  
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  On the southern bank, the river exhibited a depositional phase around Neemati–Jorhat and around Kaziranga National Park areas.
  

2. 
   Safety
   

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  The Brahmaputra due to the presence of strong under currents is not a safe river for bathing in the way other rivers are, particularly during the rains when it swells up into terrifying size
  
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  The Brahmaputra flows through a seismically active region, which has the effect of causing it to carry one of the highest sediment loads in the world.
  
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  The Brahmaputra valley is considered a tectono-sedimentary basin, 720 km long and 80–90 km wide, underlain by recent alluvium about 200–300 m thick consisting of clay, sand, and pebble. Because the basin is underlain mostly by very young and unweathered sedimentary formations, the river carries mainly fine sand and silt with very little clay. Due to their strategic location close to the border of the colliding Eurasia (Chinese), Indian, and Burmese tectonic plate boundaries, the Brahmaputra valley and its adjoining hill ranges are seismically very unstable, falling in zone V (very severe seismic intensity zone) under seismic zoning. Active seismicity of the North Eastern region has caused extensive landslides and rock falls on the hill slopes, subsidence and fissuring of ground in the valley, and changes in the course and configuration of several tributary rivers as well as the Brahmaputra mainstream.
  
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  Records show that catastrophic floods occurred in 1954, 1962, 1966, 1972, 1973, 1977, 1978, 1983, 1984, 1987, 1988, 1991, 1993, 1995, 1996 and 1998
  

3. 
   Rainfall
   

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  The precipitation here is mainly due to Southwest monsoon, heavy rainfall occurs from June to September. Average annual rainfall in this valley ranges from 1750mm in Kamrup District to about 6400 mm in the North-east Hilly region.
  
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  The average rainfall is 274 cm with minimum of 175cm and maximum 640 cm. the drainage system of the river differs from that of other rivers of the world. It is the only example in the world where the drainage system runs in a diametrically opposite direction. The distinct advantage of these rivers is that the water does not freeze into ice in the winter, which is one of the most difficult problems of the river of some western countries. The total drainage area of Brahmaputra is about 93800 sq.kms.
  
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  The climate of the Brahmaputra basin is highly variable. The Tibet drainage is cold and dry and has the lowest run-off among the various basins, ~ 0.3 m yr–1; the Eastern Syntaxis region has the highest run-off, ~ 5 m yr–1. Run off for the other basins falls between these two extremes, the eastern and southern basins have ~ 3–4 m yr–1, whereas for the Himalayan basin, it is 1–2 m yr–1. Sediment contributions from the southern tributaries are insignificant16 and hence this sub-basin is not considered for erosion rate calculations
  

4. 
   Drainage
   

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  Gradient: The gradient of the Brahmaputra River is as steep as 4.3 - 16.8 m. /km. in the gorge section upward of Pasighat, but near Guwahati it is as flat as 0.1 m. / km
  
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  Discharge: The River carries 82 per cent of its annual flow during the rainy season (May through October). The maximum discharge of the river at Pandu (in Guwahati) on 23-08-62 was 72794 m3s-1 and the minimum discharge at the same point on 20-02-68 was 1757 m3s-1.
  
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  The Brahmaputra basin erodes more rapidly compared to its western counterpart, the Ganga drainage, possibly because of higher run-off in the Eastern Himalaya
  

The hotspots along Brahmaputra for tourism development are:

Dipar Bil is an important water body in Guwahati. It is fresh water lake in a former channel of the Brahmaputra River. It has been declared as one of the Ramsar Site and is recognized as wetland of national importance and has been proposed as a Bird Sanctuary in the Master Plan for Guwahati – 2001. The bil is the natural habitat of many species of birds, various aquatic life and vegetation. It is proposed to develop the adjoining area connecting the National Highway as Capital Complex and the Bil area to form a nature reserve as extension of the Capital Complex.