8/3/2023 0 Comments Formation of a meander![]() ![]() Material eroded here is deposited downstream in point bars. ![]() Not only are cut banks steep and unstable, they are also the area of a stream where the water is flowing the fastest at a higher pressure and often deeper, making them rather dangerous. Given enough time, the combination of erosion along cut banks and deposition along point bars can lead to the formation of an oxbow lake. Often, particularly during periods of high rainfall and higher-than average water levels, trees and poorly placed buildings can fall into the stream due to mass wasting events. Normally, cut banks are nearly vertical and often expose the roots of nearby plant life. Satellite image showing a meander with a cutbank on the external margin and a point bar in the internal margin of the water stream. This makes it easier for the river to evolve in its form within time and space as the horseshoes migrate through the erosional plain in a horizontal way rather than a vertical way, as shown below (4):įigure 7. Diagram that shows the relation between the river speed (Y axis), the particle size (X axis) and the total amount of particles eroded, transported and deposited.Īs meandered streams are mostly found in plains, the speed of the flow is not big enough so as to carry big sized particles, which explains why landforms found in this kind of water streams are composed by thin particles. The competence of a stream increases proportionally to the mathematical square of its speed (3).įigure 3. The key lays in the water speed fast water streams have a larger competence that the slower ones, despite the size of the water stream beds. By its competence: which measures the ability of a stream to transport particles according to the size of these, rather than the quantity which is carried away.Large rivers with high flow speeds have a major capacity. As larger the water that flows in the stream is, the higher its capacity to transport the sediment. By its capacity: which refers to the maximum amount of sediments that may be carried.The ability of a stream to transport particles can be described in two ways: Transportation of sediments through a water stream according to the size of particles. Or, you can e-mail photos to us at and we may share them on this page or on social media.Figure 2. Please see the USGS social media sharing policy at. If you tag us with you are giving us permission to use your image. Here at USGS, we study how meanders are formed and can even model them to predict how the river may continue to change in the future, to better understand flooding hazards.Ĭan you find a meander in your area? If you don't see a river, see if you can spot a sidewalk or path that meanders, or watch how a drop of rainwater flows down a slightly sloped surface - does it make a straight or curvy path? Take a photo of a meander and tag us #findafeature or send it to us at be watching Instagram and Twitter for some great #findafeature examples and may share them here with the first name or initials of the contributor, and a general location. Due to erosion on the outside of a bend and deposition on the inside, the shape of a meander changes over time. ![]() This is why you often see sand bars and beaches on the inside of the curve. Why is this? Water is pushed to the outside of a bend, and erodes the curve further, while water on the inside is slower and deposits sediment. Once a meander starts, it often becomes more and more exaggerated. As a river makes its way through an area that is relatively flat, it often develops bends as it erodes its way through the path of least resistance. A meander is when water flows in a curvy, bendy path, like a snake. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |