BRAHMAPUTRA IN ASSAM

Brahmaputra

Brahmaputra it is one of the biggest and most important river of the world. It is a major river of Asia. The Brahmaputra originates at a place 30o31’N latitude and 80o80’E longitude, near the upper waters of the Indus and Sutlej, and a little to the east of the Mansarovar Lake in Tibet between the Kailash range and the Himalayan range lying at an altitude of 5150m. It is a Trans-boundary river. A Trans-boundary river is a river which touches an international boundary. It does not only touch an international boundary, it also travels through different country. From its origin the Brahmaputra travels through three different countries before it merges in to the Sea. Brahmaputra river travels almost 29, 00 Km from the point of its origin to the point where it merges in to the Bay of Bangel at Bangladesh. While most Indian and Bangladeshi rivers bear female names, this river has a rare male name. Brahmaputra as it means “Son of Brahma”, Where Brahma is one of the GOD of Hindu and “Putra” means Son. Actually the native inhabitants, i.e., the Bodo’s called the river as “Bhullam-buthur”, which means “making a gurgling sound”, later Sanskritized into Brahmaputra.

As the river travels through different regions of different countries, it has different names in different languages. In the source region the river is known as Matsang Tsangpo or Tamchok Khambab. Further downstream, it is known as Tsangpo (means purifier). After flowing about 1700 km in Tibet, the river enters into Arunachal Pradesh of India near Korba by the name of Siang through deep gorges, rapids and cascades. Here in Arunachal Pradesh three tributaries join with Siang. After flowing about 200 Km in hilly areas it appears in the plain near Pasighat and here it takes the name as Dihang. Then it enters in Assam where it meets the Dibang from the North and the Lohit from the East near Kobo. From this tri-junction, the river assumes a gigantic size and takes the name of the Brahmaputra.

In Assam: -

Here in Assam a large number of tributaries originating from the Lower range of Himalayas, Nagaland hill, Patkai range and Meghahalaya join the Brahmaputra after traversing through the basin. Brahmaputra is the only river in the world which receives more than thirty tributaries throughout its length. Due to joining of the tributaries, the Brahmaputra transform into much bigger size towards the downstream. Due to its gigantic size Brahmaputra never flow through the same area. In recent study it has comes to clear that in the last thirty years the Brahmaputra shifted almost 1 to 10 km in some places from its original flowing area.

All the tributaries of the valley are rainfed and from up with rain. The precipitation here is mainly due to South West monsoon. Heave precipitation here from June to September. All those tributaries experience number of flood waves as per rainfall in respective catchment but have very nominal impact. If the flood of the tributaries co-insides With the flood of the Brahmaputra it causes severe problem and devestation. The tributaries namely Subansiri, Ranganadi, Dikrong, Buroi, Borgong, Jiabharali, Dhinsiri [North], Puthimari, Manas, Beki, Aie, Sonkosh are the main tributaries on the North while the Noadehing ,Buridehing, Desang, Dikhow, Bhogdoi, Dhansiri[South], kopili, Kulshi, Krishnai, Dudhnai, Jinjirana are main on the South Bank of the river Brahmaputra.

The meteorological conditions in catchment of Brahmaputra in Tibet and in India are different and lie in different climate Zones. The mean annual rainfall over the entire catchment including Tibet and Bhutan is about 2500mm. The rainfall in Brahmaputra basin is mainly due to South West monsoon and out of total annual rainfall, 85% occurs during the monsoon months from May to September, besides the valley gets a good amount of rainfall in the month of April and May due to thunderstorm activities which account for flood during heavy rain in June, When the soil is already saturated and river bank in full stage.

The tributaries of the Brahmaputra for most of their length drain the steep slope of the Himalayas to the south where rainfall is heavy. Consequently they not only carry heavy runoff, particularly where slopes are denuded of forest, but also very large volume of detritus, the result of excessive soil erosion, to risen the land surface in the plains by bank spill. The major portion of the heavily silt laden floodwaters carried to the Brahmaputra not only aggravates its flood congestion, but also adds to the silt charge of the river.

As the other third world countries India is also in the stage of developing. Today in India one of the major problem is its growing population. Due to its number of population India is placed in second position in the world. Like other states of India Assam is too affected by this developing stage. A rapid increase in population has resulted in an acceleration of deforestation to meet the increasing demand for food, fuel wood and to build their home. Deforestation of steep slopes is assumed to lead to accelerated soil erosion and landslides during monsoon precipitation, which in turn is believed to contribute to devastating floods in the downstream regions. Just like this due to rapid urbanization and industrialization without proper planning are destroying the catchment areas of the Brahmaputra & its tributaries. Rainwater carries the eroded soils to the sub-tributaries or tributaries and finally to the Brahmaputra. It increases the riverbed level and it reduces the water carrying capacity of rivers, causing floods due to bank overflow. The great earthquake of 1950 created havoc, specially in the upper reaches of the Himalayas in and around the Siang and the Diboug river courses as well as in the upper Assam plains. There was considerable impact on the topography on both sides of the Brahmaputra Valley. This natural calamity was mainly responsible for the abrupt changes in the river ecology. The river Brahmaputra and its many tributaries in upper Assam badly suffered due to blockage caused by uprooted trees, boulders and soil erosion

Ploughing & cutting of hilly land makes the land surface more susceptible to soil erosion. Surface run-off can easily wash away the topsoil from cultivated lands. This surface erosion reduces land elevation, which in turn increases flooding intensity in an area. Heavy monsoon showers remove the surface soil through runoff and sometime it causes landslide in hilly area. Eroded sediments are deposited on the riverbeds, reducing the water carrying capacity and increasing flooding propensity in a watershed. Soil erosion also reduces land elevations and increases elevations of riverbeds, contributing to increased flood depths.

A rapid increase in population in the Indian Subcontinent over the course of the 20th century has resulted in an acceleration of deforestation to meet the increasing demands for food, fuel wood and to make their home. Deforestation of steep slopes is assumed to lead to accelerated soil erosion and landslides during monsoon precipitation, which in turn is believed to contribute to devastating floods in the downstream regions.

Pollution: -

Today one of the major problem of Brahmaputra is its pollution. The Brahmaputra which drained the North-East India contains almost 30% of countries total Water Resources. Though it is the second largest waterway in India, its immense navigational potential remains almost unused. But surprisingly Brahmaputra is used to flush untreated rural, urban, municipal and industrial wastes.

Pollution is divided into two types, one is point pollution and the other is non-point pollution. Nonpoint source (NPS) pollution is water pollution affecting a water body from diffuse sources, rather than a point source which discharges to a water body at a single location. NPS may derive from many different sources with no specific solution to rectify the problem, making it difficult to regulate. According to the U.S. Environmental Protection Agency (EPA), nonpoint source pollution is the leading cause of water pollution in the United States today, with polluted runoff from agriculture the primary cause.

Other significant sources of runoff include hydrological and habitat modification, stormwater runoff, and silviculture (forestry). Another important cause of NPS pollution is urban runoff of items like oil, fertilizers, and lawn chemicals. As rainfall or snowmelt moves over and through the ground, it picks up and carries away natural and human-made pollutants. These pollutants are eventually deposited into bodies of water, such as lakes, rivers, wetlands, coastal waters, and underground sources of drinking water. The point and non-point sources of surface water pollution are creating chemical and biological contamination, channel contamination and basin contamination and the existing management efforts are incapable to meet the problems. In Assam there is two major point source of water pollution, which are creating a remarkable water pollution. These are Pulp and paper mill of Jagiroad and Refinery of Guwahati. Refinery of Guwahati discharge untreated effluents directly to the Mora Bharalu without any regard to the environment.

Liquid Inorganic wastes: -

Most of the inorganic liquid wastes come from industry, and their dilution in large river waters renders them harmless. Some inorganic toxic wastes can become concentrated up the food chain to fish. Many of the pollution incidents which have been resulted in many parts of the world in largest number of deaths and serious injuries from water pollution have been arisen from human ingestion of fish, or crops contaminated with heavy metals or other inorganic compounds.

Liquid Organic wastes: -

Wastes when disposed of in water, bacteria and other micro-organisms combine with oxygen dissolved in water to break them down, can be termed as “oxygen demanding” wastes. Liquid organic wastes include sewage, many wastes from industries (especially industries producing agricultural and tannery products) and run off from rains, floods and stroms which picks up organic wastes from land.

Brahmaputra in Bangladesh: -

Overall compared to the other major rivers in India, the Brahmaputra is less polluted but it has its own problems. But when the river Brahmaputra enters in Bangladesh it becomes a most polluted river. Here in Bangladesh Brahmaputra joins with another river, Ganga coming from India. The Ganges-Brahmaputra delta is the largest delta in the world and the rivers contribute one-third of the global sediment transport to the world oceans. The rivers flow through 10 per cent global population and carry untreated rural, urban, municipal, and industrial wastes to the Bay of Bengal. India ranking the tenth largest industrial country of the world but most industrial plants use outdated and polluting technologies. The river Ganges flows through more than 700 cities and about 120 million liters of waste water added daily. DDT factories, tanneries, paper and pulp mills, petrochemicals and fertilizer complexes, rubber factories and host of others use river to get rid of their waste. 70 per cent of surface water in India is polluted. About 6,000 large and medium industries and 24,000 small industries are operating in Bangladesh discharge untreated effluents (10 to 100 times the allowable levels permissible for human health) directly to the rivers without any regard to environment. All of Bangladesh's sewage is flushed directly into Ganges and Brahmaputra Rivers. Increase chemical based agriculture and destruction of natural environments due to structural measures in this subcontinent pose the greatest threat of surface and ground water contamination.

Problem of Brahmaputra: -

Today the major problem of river Brahmaputra is not its flood but the proposed “Yarlung Tsangpo Hydroelectric and Water Diversion Project” on it. China Government proposed to make Dam on the river Brahmaputra to fulfill their electric power supply and also they will turn the river towards the country side to fulfill their increasing demand for fresh water and to fight with the drought ness of the country. It is anticipated that such a plant would generate 40,000 megawatts electricity. It has been estimated that construction may start very soon. It is feared that there will be displacement of local populations, destruction of ecosystems, and an impact for downstream people in India and Bangladesh The project is criticized by India because of its negative impact upon the residents downstream. Analysts think that the livelihood of up to 100 million people could be at stake and therefore voice fears that the completion of the water diversion component of the project could sparkle an Indian-Chinese water war if no proper management is taking place. If China succeeds in the “Hydro electric power project” it will make the river Brahmaputra dry. So it will make north-east India drought. Eventually it will increase the number of people under the poverty line.

Ecosystem of Brahmaputra:-

There are nearly 200 species of aquatic vertebrates, almost exclusively fishes, in the Brahmaputra River System. This faunal composition includes not only a wide variety of food-fishes, but also about 50 varieties of aquarium fishes. The most spectacular animal in the Brahmaputra is undoubtedly the river dolphin, Platanista gangetica. The population of many species, particularly of the dolphin, is in steady decline. River dolphins, mostly juveniles, often entangle themselves in gill and drift nets, while feeding on trapped fishes. Proper implementation of Indian Fisheries Act, especially a total ban on destructive nets and on killing of brooders and juveniles by explosives and poisoning should be strictly implemented. Poor communication facilities in remote riverbank areas and lack of funds are two important reasons for the slow progress of the conservation of river dolphin and this endangered species is now on the verge of extinction. The anthropogenic activities and their impact on the habitat of river dolphin are discussed.

N.B. Collected from various source.

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