Bartley Water Floods

In this investigation, I will be investigating changes along the long profile of a river. The river I will be studying is Barley Water which is located in the north-east of New Forest National Park in southern England.
Bartley Water is a tributary of the River Test and it is 27 km in length including all its smaller tributaries. It runs from Bartley to Eling and flows east into Southampton Water which goes into the Solent. The catchment area goes around the edge of Bartley, Minstead and Ashurst and through parts of Totton and Eling, equalling a total area of around 40 km2. The source of Bartley Water is 37m above sea level. Bartley water is a third-order stream (also called a headwater stream) and has a drainage density of 0.675 km/km2 showing
This is an area around the river that is covered when the river floods. It is a fertile area because of the alluvium (fine layers of clay, silt and other sediments that are deposited when the river floods) which makes it a good place for agriculture. In fact, if the alluvium is stable enough to support vegetation, salt marches may form. A build-up of alluvium can create levees, another lower course feature, which raises the river banks. Artificial levees may also be built to reduce the impacts of flooding. Another feature that could be formed is a delta. This forms when river mouths become choked with sediment, causing the main river channel to split into hundreds of smaller channels. However, I don’t think Bartley Water has this because it cannot be seen on the map and also it doesn’t fulfil the conditions for a delta to form.

There are many ways in which a typical river changes along its long profile. The Bradshaw Model can be used to demonstrate this. As the river goes downstream, the discharge, occupied channel width, channel depth, average velocity and load quantity increases, but load particle size, channel bed roughness and slope angle (gradient) decreases. I will be investigating four key questions using the Bradshaw Model for Bartley Water to see if the same relationships can be
The gradient should decrease as you go downstream because the river meanders along the land rather than erode into it and follow a straight path. Therefore, it covers a decrease in height over a longer distance the further downstream you get.

Key Words

Abrasion: Bits of rock and sand in the river grind down river banks and river beds like sandpaper.
Alluvium: load particles (clay, silt, sand and gravel) deposited by a river.
Attrition: Water smash rocks and pebbles on the shore into each other, and they break and become smoother.
Discharge: The amount of water in a river at any given point and time. It is measure in cumecs (cubic metres per second).
Friction: A force that is created when water comes into contact with vegetation/ rocks in the river. It resists the relative movement of the river.
Gradient: the slope or steepness of the river profile.
Hydraulic radius: Ratio between the wetted perimeter and the cross-section area.
Load: the sand, pebbles, boulders, or other debris transported by the river.
Velocity: The rate of water movement, often measured in metres per second.
Wetted perimeter: The perimeter of the cross sectional area (banks and bed) that is in contact with the