See a model meander formation answer , which you can annotate. These landforms are very closely linked to meanders and ox-bow lakes and are combined erosion and deposition landforms. They are created by;.
Braided rivers are basically rivers that have multiple channels and islands of sediment in between those channels.
We find braided rivers in deltas, in areas where the river channel banks are made of easily erodible material or in areas of high sediment load where discharge varies e. Potholes are round to oval shaped holes in the bedrock of a river bed.
They are created where sediment accumulates within naturally occurring small depressions on the rock surface on the river bed. Turbulent flow swirls the stones called grinders around in the depressions, widening and deepening them through the prolonged process of abrasion. As the holes gets bigger even bigger debris can become trapped in the pothole, and this material is again used as an abrasive tool. Rapids are areas along the rivers course where water becomes more turbulent often creating white water which canoeists and rafters love so much!
It is caused by a localised increase in gradient along the rivers gradient or where the river flows over alternating bands of harder and softer rocks. These are often linked in with pool and riffle sequences the rapids form the riffles. The pools are areas of deeper water whereas the riffles are areas of shallower water. The pool is an area of greater erosion as the water is deeper and therefore flows faster, whereas the riffles encourage deposition because they are shallower.
It is thought that it is within these features that meanders start to develop from straight channels, as the water is forced to move from side to side around deposited obstacles.
Click here for full screen version. Landforms of fluvial erosion and deposition. How Deltas are created Deltas are depositional landforms that are created from the loading of sediment onto the land as the rivers capacity to carry that sediment is reduced. The process of formation is as follows; 1.
Waterfall — High Force on the River Tees Waterfalls are one of the most spectacular land features created by rivers and area created by vertical erosion over bands of varying rock resistances. Back to top Meanders and Ox Bow lakes — e. River Till near Wooler Meandering rivers result in widening of the river valley and the production of Ox-bow lakes. They form by the following process; The sequence starts with a pool riffle sequence.
As the water enters the meander it is faster on its outside edge because it is deeper it has a larger hydraulic radius so there is less friction acting upon the water. On the inside bend of the meander it is shallower it has a smaller hydraulic radius so more friction from the rivers bed and bedload act upon the water, slowing it down.
On the outside of the bend a steep river cliff or bluff forms where the processes of Hydraulic action and abrasion get to work eroding the outside of the bend. As the velocity slows on the inside of the bend critical deposition velocity is often reached and deposition occurs.
This creates a point bar or slip off slope. This Helicoidal flow of the river causes the river to move laterally across the flood plain. If the meander neck gets really narrow it can eventually cut through, where the 2 outside edges of the meander edge closer together until the meander bed is cut through during a period of high flow. However, as a river reaches the end of its journey, energy levels are low and deposition takes place.
Lower course — the final course of the river is where the land is a lot flatter. The river channel is at its widest and deepest as it flows towards its mouth. The lower course of the river is where the it comes to meet the sea at the mouth, and starts at the relatively straightening path preceeding it, surrounded by flat land.
Features of the Lower Course of Rivers: High Volume and Discharge — At the lower course of a river, the river is at its biggest volume capacity. All rivers naturally change their path over time, but this one forms meanders the technical name for these curves at an especially fast rate, due to the speed of the water, the amount of sediment in it, and the surrounding landscape.
In the lower course, when a river floods it tips its contents onto the flood plain, leaving behind many minerals in the soil, even after the river water has drained away. The flood plain is often used for farming because all of these nutrients make it fantastically fertile! The channel is wide and deep. The river has less friction to overcome which means that the river can flow faster. The middle course of a river is found on gently sloping land, and is typically identified by its meandering path — the sweeping side to side curves.
The middle course has two main features — meanders and ox-bow lakes. Begin typing your search term above and press enter to search.
Press ESC to cancel. Skip to content Home Physics Is it possible to have erosion without deposition? Ben Davis September 25, Is it possible to have erosion without deposition? What is a result of deposition? What are 3 examples of deposition? VAT reg no Main menu. Subjects Shop Courses Live Jobs board. View shopping cart. View mytutor2u. Account Shopping cart Logout. Explore Geography Geography Search. Explore Blog Reference library Collections Shop. Share: Facebook Twitter Email Print page.
This can happen for a combination of reasons: A decrease in energy for example, on the inside of a meander bend An increase in capacity total load Both of these situations will result in a decrease in competence maximum size or weight of load transported , and so, to the deposition of sediment.
Floodplains Land either side of the channel is susceptible to flooding. Each time this happens, a layer of silt or alluvium is deposited and comes from two main sources of sediment: Overbank deposits fine sands, silts and clays Channel deposits from slip-off slopes gravels and coarser deposits As a river spills over the side of the channel there is a sudden increase in wetted perimeter the part of the channel in contact with water and so a fall in hydraulic radius hydraulic radius is a measure of channel efficiency and measures the relationship between wetted perimeter and cross-sectional area — the higher the hydraulic radius, the more efficient flow is as less energy is lost through friction.
Deltas Deltas are formed when a river enters a standing or low-energybody of water a lake, lagoon or sea. The depositional form a delta takes depends on the relative densities of river water and sea water: If densities of the two bodies of water are similar, they mix freely and consistent deposition occurs.
Coarse sediment occursclose to the mouth but deposition if finer suspended sediment spreads out further into the sea. Hypopycnal flow If river water is denser if it is colder water or a heavier load , water may sink rapidly and cause offshore deposition that may produce a stunted delta.
Hyperpycna l flow Deposition is further determined by the process of flocculation. In order for a delta to form, certain conditions must be met: River discharge must be high enough to overcome high energy waves or high tidal ranges A largematerial load is needed — this is often provided by a rapidly downcutting river or a river which erodes through unconsolidated sediment such as boulder clay It is more favourable to have a gentle offshore gradient than a steeply shelving shoreline for deposition to occur If there is a large amount of sediment being deposited close to the mouth it may, over time, inhibit the riverdirectly reaching the sea so it divides into numerous small channels called distributaries in order to do so.
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