RIVER IN BANGLADESH

Bangladesh is a riverine country. About 800 rivers including tributaries flow through the country constituting a waterway of total length around 24,140 km. Most of the country's land is formed through silt brought by the rivers. Following is a list of some of the major rivers of Bangladesh:There are quite a few rivers in the district of Bogra. Taking the Karatoya as the central dividing water-channel of the district, the other rivers may be classified into the eastern and the Western systems. The course of all the rivers is, with such allowances as must be made for beds and windings, nearly uniform north and south. The eastern rivers are Monas, Charkadaha and Khamati besides a few other smaller ones. Through the khiar tracts in the western parts of the district flow the Nagar, the Tulshiganga, Nagar and other minor streams. All the western rivers are the tributaries of the Atrai which itself flows into the Jamuna 12 miles north of the confluence of that river with the Ganges (padma) at Goalunda. Evidences show that the rivers Karatoya and Nagar have changed their courses in the past, while the Jamuna, lying on the eastern boundary of the district, is in fact a new channel of the Brahmaputra. A very small river, Tarai used to occupy more or less the present location of the Jamuna. At that time the Brahmaputra used to flow to the east round the foot of the Garo Hills. The earliest evidence of the Brahmaputra river consists of a group of large Brahmaputra-size river scars which extend into the Sylhet basin flanking the southern edge of the Shillong plateau . The main river apparently extended east beyond this locality and then swung south into the Bay of Bengal. By the time of Rennell's mapping, this course had been abandoned in favour of a shorter route down what is still called the old Brahmaputra river past Mymensingh.By the early 1770s the major diversion of the Brahmaputra into its present channel, west of the Madhupur jungle, had occurred. There is no complete agreement as to when this diversion down the Jenai river of Rennell occurred. Apparently by 1830 the diversion of low-river flow down the new channel was complete. The rivers of the former Nadia district, of which Kushtia was a part, were grouped together and known as "Nadia Rivers" because of the peculiar condition of the Nadia district and special measures taken by the Government to keep them flowing. All the rivers of the former Nadia district (and of the present. Kushtia for the matter of that) were offshoots of the Padma (lower Ganges). But at one time when the Ganges found its way to the sea along the course of the Bhagirathi, there must have been some earlier streams to carry the drainage of the Darjeeling-Himalayas to the sea. Bhairab is said to be one of those streams. Mter the Ganges drifted to the east and the Padma grew mighty and majestic all the drainage of northern and upper Bengal was intercepted by it. The Jamuna, nowhere less than 4 miles wide duriug rains, is running in the west and the equally important Meghna encloses the district on the east. They are connected by the old channel of the Brahmaputra running through the centre of the district in a south-easterly direction from above Bahadurabad up to Bhairab Bazar. The district of Noakhali is not intersected by so many rivers as the other deltaic districts of Bangladesh. On the west and south of the district and between the islands flows the Meghna with all its bifurcations each of which is much bigger than an ordinary river, and on the east the Feni subdivision is drained by the great and little Feni rivers. In the intervening country there are no rivers of any size and the drainage there depends on a few tidal channels or khals, of which the principal are the Noakhali khal, the Mahendra Khal and the Bhowaniganj Khal.In sharp contrast with the mainland to its south, there is a network of khals in the islands. As one advances from the older formation of chars towards the newer ones, the number of khals gradually increases. The khals gradually silt up, but where diluvion goes on, new khals come into existence and the old ones become wider and wider.

Rivers in Noakhali District

1. Meghna River 2. Dakatia River 3. Bhawaniganj Khal River 4. Mahendrak Khal River 5. Noakhali Khal River 6. Little Feni River 7. Big Feni River 8. Muhuri River 9. Seloneah River

Pabna District

The district is intersected by rivers of varying magnitude. But in fact, the river system is constituted by the Padma and the Jamuna with their interlacing offshoots and tributaries. Besides these flowing streams, the interior is visited by the abandoned beds of old rivers, most of which are dry except in the rains.

The general trend of the drainage of the Serajganj subdivision is from north-west to south-east, the rivers entering it from the north-west flow into the Jamuna after a tortuous course. In the Sadar subdivision, however, the general slope of the country is from west to east, and the main rivers fall into Hurasagar, an offshoot of the Jamuna.

Rivers in Pabna District

1. Padma River 2. Ichhamati River 3. Baral River 4. Atrai River 5. Chiknai River 6. Jamuna River 7. Kazipur River 8. Karatoya River

Rajshahi District

Excepting the Ganges or the Padma, the Mahananda and the Atrai, the rivers of Rajshahi district are of little hydrographic importance. For, most of the rivers are more or less moribund, that is, they are not active flowing streams except during the rainy season. During the rainy season these moribund rivers act as excellent drainage channels draining off a large volume of water and have a considerable current. Most of these rivers are narrow and flow in well-defined channels.

Principal rivers in Rajshahi District

1. Padma River 2. Mahananda River 3. Atrai River 4. Gur River 5. Jamuna River 6. Baral River 7. Musakhan River 8. Nandakuja River 9. Gumani River 10. Baralai River 11. Narad River

Tangail District

The newly formed Tangail district is flanked on the west by the mighty river Jamuna, which is nowhere less than 4 miles wide during the rainy season. The Dhaleshwari, first an old channel of the Ganges and then of the Brahmaputra, cuts across the south-western comer of the district on its powerful sweep to join the Meghna near Narayanganj. The old name of Dhaleswari was "Gajghata". It used to flow afterwards by the Salimabad Channel and then at last by Porabari Channell. A part of the eastern boundary of the district runs close to the Banar river. The river Bangshi flows almost down the middle of the district, branching out from the old Brahmaputta to the north from near Jamalpur. Bangshi falls into Dhaleswari near Savar, in Dhaka district. The Bangshi forms a natural barrier to the Madhupur Jungle on the Tangail side, all the way from Madhupur to Mirzapur. It is only fordable at two or three places near Basail on its my to river Meghna. Dhaleswari itself however takes out from the Jamuna from inside Tangail district.

Among other important rivers of the district, Lohajang is worth mentioning. It flows past the district headquarters of Tangail and is almost dead at present (in moribund condition). Other rivers are Khiru, Nanglai Nadi, Atai, and Jhinai. The old Brahmaputra's most important off-shoot is the Jhinai; striking off near Jamalpur it rejoins the Jamuna north of Sarishabari, while another branch flows past Gopalpur. Now these sub-systems of rivers, viz, Bangshi and Banar, and the Lohajang, Khiru, Nangtai Nadi, Atia and Jhinai are all dying out because of the shift of the old Brahmaputra river from its former channel to the present Jamuna channel.

The most important question in connection with the river system of Tangail vis-a-vis Mymensingh district is when and why the Bmbmaputra river changed its main old channel. During the last 150 years or so, this diversion of the old Brahmaputra to its present Jamuna channel has considerably prompted the geographers and geologists to enquire deep into it. Two theories are advanced: As explanation of the diversion, one theory describes the gradua1 uplift of the Madhupur Tract and a final trigger action of the Teesta diversion in 1787 as the chief factor; and the other theory states that the Brahmaputra diversion resulted directly from a major increase in its volume of water due to beheading of the Tsangpo river of Tibet by Dihang, a tributary of the then small Brahmaputral. It has now been proved that the great Tibetan river Tsangpo joined the Brahmaputra about 1780 and this accession was more important than the Teesta floods in deciding the Brahmaputra to try a shorter way to the sea.

With the help of Major James Rennel's maps (1764 to 1773) and of the Revenue Survey it is possible to reconstruct the history of the Bengal Delta and its river systems. It was Rennel who carried out the first ever accurate cadestral surveys and laid the basis for the geographical study of Bengal. At the end of the 18th century, probably as a result of the great Tista floods in 1787, the Brahmaputra changed its course and joined the Padma at Goulundo. No piece-meal study of an intricate river system is possible, without distortion and inadequacy.

Even though we assume that the change in the course of the main waters of the old Brahmaputra took place suddenly in 1787, the year of the famous flooding of the Teesta river, the Teesta has been always a wandering river, sometimes joining the Ganges, sometimes being shifted oastwards by the superior strength of the river Ganges and forced to join the Brahmaputra at last.

Whatever might have been the cause, it is obvious that by 1830, the diversion of old Brahmaputra was complete, ushering in a gradual but radical change in the river system of the Tangail district. The old channel of the Brahmaputra had been reduced to its present insignificance.

In 1850 Sir Joseph Hooker wrote "we are surprised to hear that within the last 20 years the main channel of Brahmaputra had shifted its course westwards, its eastern channel silted up so rapidly that the Jamuna eventually became the principal stream.