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Canals and rivers

Rivers are usually born from streams, glaciers, or natural changes in highlands or mountain ravines. A kind of tremendous speed is transmitted in the water rushing at high speed from the mountains thousands of feet high. This fast-moving stream of water is known as a river when it crosses land. His youth when the river flows in hilly areas. During this time the river carried out extensive excavations and extracted gravel, sand, silt, etc. from the source and threw them into the sea very easily. Rivers have been eroding the earth's surface for so long. His work ends when all the river basins are eroded into plains or almost plains. This work of the river from the source to the estuary is divided into three stages.

River youth [source]
In this condition the main function of the river is erosion and carrying. Usually the hilly condition is the youth of the river. At this time the river carries big stones. The friction of these stones erodes the bottom of the river and creates big holes. River erosion in the highlands has resulted in canyons, canyons and waterfalls.

River maturity [source]
In this condition the river is a little stagnant. As a result, the speed and carrying capacity of the river also decreases. Usually when the river enters the middle or valley, it refers to the mature state. In this condition canyons, rapids, waterfalls etc. are no longer seen. The height of the mountains and the watershed between them is also lower than before.

River aging [source]
In this condition the erosion capacity of the river is greatly reduced. However, the demolition work was short-lived. This condition of the river is usually in the plains. It may have high ground somewhere. At this time the speed of the river decreases so much that the river changes its course whenever there is a slight obstruction. The river is very winding in this part. Along the way creates a horse-shaped lake. In this condition, the river often causes floods on both banks during the monsoon season. The water of the river spreads around. As a result, sand and silt spread on both shores. Char also rises in the chest of the river. However, rivers do not always flow like this. Occasionally earthquakes can rejuvenate a river. Apart from this, other reasons can also increase the intensity and speed of the river.
If the ground movement takes a massive size, then it migrates to the oasis. This created new mountains. There are a number of rare rivers in the world that have continued to erode the power of the rising mountains and have been able to maintain their existence even after the rise of the mountains. ঐ All rivers are called foreground rivers. For example, Colorado, Indus and Brahmaputra can be named. Colorado flowed there long before the Rocky Mountains and the Indus and Brahmaputra rivers upstream of the Himalayas. [1]

Types of rivers [edit]
The main rivers are usually springs from glaciers, such as the Padma Gangotri Glacier. The tributary originates from another river. Such as the tributary river of Buriganga Dhaleshwari. Tributaries usually merge and flow into other rivers, such as the Atrai River. A major river can be a tributary of another river. Again, this stream is divided into two parts on the basis of masculine and feminine words. The streams whose names are feminine are called rivers. Their names are long vowel karanta. Such as: Meghna, Jamuna, Karnafuli, Kushiyara etc. The streams whose names are masculine are called rivers. Their name is Hrasvasvara Karanta. Such as: Kopotaksh, Brahmaputra, Nile river etc. However, this rule applies to all rivers whose names are mythical.

Geographical knowledge and mathematical formulas of the river [source]
The source of the river is usually a high-altitude mountainous region, where icy water and rainwater flow through a slope to create strong currents. The periodic integrated process of multiple small streams erodes the mountains and creates rivers.
The stages are (Holmes, 1951)
Patprabha-Mihinali-Shiranali-Guhanali-Nadi valley. In fact, erosion at the source of rivers flows through a number of regulators, such as-

E = F (S +, Q +, V +, R-); When-
E = level of erosion
F = workmark
S = slope of land
Q = flowing
V = flow velocity
R = friendship and hardness

It is easy to assume that the reaction and influence of those favorable and unfavorable regulators are essential behind the creation of a river. Again, river flow and erosion are proportional, but the flow rate depends on the slope of the basin, which, according to the geologist Chazi's equation, is as follows:
V = CVRS; When-
V = flow velocity
S = slope of land
R = land friendliness and rock hardness
C = constant number

The structure, stage, nature and function of any river are constantly evolving. These stages of transformation are comparable to a living organism according to the ‘organic concept’. There are three main stages of the river from beginning to end-

Young → mature → old
Erosion → Transportation → Storage

The source of the major rivers flowing over Bangladesh is the Himalayas. Ice water and rain water flow in a spiral speed from north to south. Their destination is the Bay of Bengal. [1]

Rivers of Bangladesh [source]
Bangladesh is said to be the land of thousands of rivers. However, the Bangladesh River Research Institute does not have the exact number of rivers in Bangladesh. Where all the rivers originated and ended or where one river crossed another river is still unknown to man. According to many researchers, the total number of tributaries and tributaries in Bangladesh is 225. But rivers, tributaries