The school curriculum includes a course on the study of the water system of our planet. Rivers are one of the important topics. Their significance is great enough. We can say that it is thanks to their waters that life on land is possible. They shape the climate, vegetation, wildlife and much more. Numerous cities receive electricity from newly built hydropower plants.
In this article I would like to understand in detail what a river floodplain is. Study the definition of this part of the watercourse. It is also very important to know what types it is. So let's get started.
Definition
Floodplain is a section of the valley along the direction of the water flow, which is periodically flooded. Basically, this phenomenon occurs during floods, since water does not fit in the channel.
Usually, floodplains are formed near rivers that flow in the plain, you can also find a floodplain in the mountains, but less often. During floods, this area is periodically flooded. The floodplain is truncated by terrace ledges, sometimes it is located in separate clusters from different sides of the channel.
Varieties by size
The river floodplain can be divided into two types: low and high. Thesethe names speak for themselves: the classification is based on certain dimensions.
The high floodplain reaches 5 to 15 m in height, while the low floodplain is only 0.5 to 2 m high. The latter, as a rule, is often flooded. The high one is covered with water during more abundant floods. Their width can vary from 10 meters to several kilometers. It is also worth noting that the floodplain of the river has the feature of either increasing or decreasing in size. When expansion occurs, branches are formed, and in the narrowed areas of the valleys, the flow rate increases and erodes the channel. Such cases are typical for mountain rivers.
Classification by species
Floodplains are divided into 5 types:
- segment;
- one-sided;
- terrace;
- bundled;
- delta.
The formation of a segmental floodplain is associated with the meandering of the river itself, as well as with its division into segments that are located along both edges of the channel.
Watercourses that tend to move to one side usually have one-way floodplains. This area stretches along the riverbed for tens of kilometers. It can also diverge into different sections with sleeves.
The terrace floodplain is located in a lower part of the relief, sometimes overgrown with urema (shrubs or forest in the river floodplain). When small streams of water carry fine weight material, it slowly settles into the floodplain. The surface is often perfectly flat.
The bunded floodplain is formed due to the increase in heightriverbanks. As a rule, this happens on straight places of the river on different sides. Since the flow practically does not change its location, the ramparts form dams that are located above the floodplain. They can be found among the course of the Dnieper, Amu Darya, in the lower reaches of the Kura.
The delta floodplain of the river is the widest and smoothest, its surface does not change. It is sometimes divided by a network of lakes, streams and swamps.
Floodplain lands are valuable lands that can be used for the development of animal husbandry and hay meadows. They are also used for growing crops that need high moisture, such as forage grasses, vegetables and various fruits. This is not suitable for sowing cereals, as they need zonal soil.
