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# Formation of Landforms The formation of landforms depends on the load a river carries. ## Course of a River * Rivers normally originate in mountains from glaciers or from lakes. Some rivers like those in the Deccan Plateau region are formed due to the meeting of various streams during rainfall....

# Formation of Landforms The formation of landforms depends on the load a river carries. ## Course of a River * Rivers normally originate in mountains from glaciers or from lakes. Some rivers like those in the Deccan Plateau region are formed due to the meeting of various streams during rainfall. * The place of origin of a river is called its source. * Where a river enters the sea or disappears before joining the sea is called its mouth. * The streams or small rivers which join the main river are called its tributaries. * Where a river divides into channels or smaller rivers, they are called distributaries. * The path along which the river flows is known as the course of a river. From the source to its mouth, a river is divided into three main sections - Upper Course, Middle Course and Lower Course. These three sections are also called the Profile of a River. ## Upper Course * In the upper course of its flow, the river is young (i.e. it is in the initial stage). * At this stage, the river flows swiftly, for the gradients are steep. * The upper course of a river generally lies in a hilly area and the river flows a considerable distance over a steep slope. * Along its course, it erodes its bed and banks; and carries large boulders of rock with it. * Under the impact of rush of water and the load the river carries, erosion action is swift and effective. * Therefore, in the upper course the dominant activity of a river is erosion. Many landforms are shaped by this activity of the river. ### Landforms The significant landforms resulting from erosion in the upper course of a river are the following: 1. **V-shaped Valleys**: A V-shaped valley is a narrow valley that has a profile suggesting the form of the English alphabet V. It is formed from a stream eroding downwards, through a process, called down cutting. These valleys are formed in the initial stages of rivers and have steep slopes. ## Middle Course * The second stage of a river is known as the maturity stage. It corresponds to the middle course. At this stage, the gradient is reduced, and the river flows more slowly. * The middle course of the river begins when it leaves the mountains area and enters the plains. * In the middle course the energy required to transport the materials is just enough to drag large particles. * Two other important characteristics of the middle course are: * the lateral cutting is more active than down cutting, and * the volume of water increases due to many tributaries. As a result of these characteristics, the river carries its load in different ways. Large particles remain suspended in water whereas smaller ones are just dragged along the river and even smaller ones are rolled along. * The river also gets wider as the volume of water and the load increases. ### Landforms of the Middle Course In the Middle Course, the work of deposition is more important than erosion. Therefore, the landforms of the Middle Course are prominent than the landforms of the Upper Course. #### Meander Rivers make longitudinal courses. They form meanders, which are common to most rivers. The channel forms a curved loop, which is a result of both erosion and deposition. Meanders generally form on a gentle slope and sufficient water flow. The river flow is diverted by the presence of obstacles, which force the river to do lateral erosion. The curvature of meanders may be more circular, or more sharp and the river meanders to form an intricate pattern, as in India and Mississippi where their meanders are more pronounced.