Each river has a source - a place where it originates, and a mouth - an area of its confluence with another watercourse. Water flows that connect to the oceans, seas or lakes are the main ones, and those that directly flow into the river are called tributaries.
They flow in the valleys, that is, places whose relief is elongated and lowered. The point of maximum decline is the riverbed . The floodplain is the part of the valley that is constantly flooded with river water.
River - what is it?
A river is a water stream, often formed in a natural way. It flows in a certain direction from its source to its mouth; feeds in various ways: snowy, glacial, underground and other waters.
Watercourses form due to the accumulation of water in the valley. As a rule, the cause of their formation is heavy and regular precipitation, melting of snow, ice, etc. During the construction of dams or dams, reservoirs are formed, which can be lakes or even seas. However, in this case, they will have no current, and they are also created most often by artificial means.
Basically, all watercourses flow along faults in the relief, there is no resistance and stress.
Channel
As already mentioned above, the riverbed is a place in the valley, the level of decline of which reaches a maximum mark. It is divided into several types. One of them is the main channel. This is the name of a certain area on the river in which most of the watercourse is located.
Depending on the size, the river bed can reach a huge width, which varies from one meter to several tens of kilometers. In this case, the depth does not increase simultaneously with the expansion of the watercourse. And very often it happens that in a place of a large spill there is shallow water. In mountain rivers, channels can have rapids as well as waterfalls. According to their trajectories, the winding lower part of the valley is distinguished - in lowland rivers, and the straight line - in mountain ones.
The former riverbed is called the old woman. As a rule, it is presented in the form of a sickle, a loop or a straight line. It is formed after, thanks to a strong current, the water stream breaks a new path. After that, most of the waters do not fall into the old channel and the so-called old man is formed. In the end, it either dries up or completely overgrows with aquatic plants.
Change of the riverbed often occurs artificially. In this case, this leads to irreversible consequences, which are then difficult to eliminate.
Floodplain
The floodplain is the part of the river that constantly gives in to flooding during floods or floods. Often its dimensions depend on the width of the channel, but not always. It can vary by several meters, and sometimes even kilometers.
The floodplain soils are fertile only if the waters of the stream flooding a piece of land bring sludge. Typically, this place is great for fishing.
Terraces are areas of the former floodplains, the water level in which is several times higher than in the channel, even during floods and floods.
The source and mouth of the river
The source of the river is the place where it begins. Often these are small swamps or streams. If the river system has a lot of sources, the main one will be considered the one that is either the most watery or the most distant from the mouth of the watercourse. Very often the beginning of the river can be considered the confluence of water bodies or water streams.
The mouth is the place where the watercourse flows. It can be any lake, sea, reservoir, another river. In its structure, it is different. For example, sometimes a delta or lip may form at the confluence of a river with a body of water.
The riverbed, floodplain, source and mouth - this is not all that characterizes the river. In addition to them, there are also coasts (borders of the watercourse), reaches (places with the greatest depth), rifts (areas with the smallest depth). And those sections of the river in which the strongest flow rate were called the core.