We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

The River Investigation Essay Sample

essay
  • Pages: 5
  • Word count: 1,180
  • Rewriting Possibility: 99% (excellent)
  • Category: river

Get Full Essay

Get access to this section to get all help you need with your essay and educational issues.

Get Access

Introduction of TOPIC

Aims

1. To find out how channel characteristics such as width, depth, area, efficiency, gradient and bedload change downstream?

2. To find out how flow characteristics, such as velocity and discharge change downstream?

Having studied rivers to a great extent at GCSE and A level I have decided to carry out a study on river processes and characteristics. I have chosen the River Brett as the location for my study due to its large drainage basin and varying stream orders, enabling me to carry out a wide ranging investigation. The River Brett is a tributary off the river Stour in Suffolk. The river Brett’s total length is 100 km.

Hypotheses

In this investigation I am going to prove the following Hypotheses:

1) All of the river dimensions will increase downstream e.g. width, depth, area and radius.

2) All of the flow characteristics will increase downstream such as velocity and discharge due to a wider and deeper river.

3) Bedload size and shape will decrease downstream.

Background and Theory of river processes

1. Hydrological Cycle

2. River Processes – Erosion

Deposition

Transportation

3. Other Factors affecting a river

Erosional Processes

Erosion is a process whereby material carried by the river wears away the bed and banks. It causes the river dimensions to become wider and deeper, or in the case of river material, smaller and rounder

Erosion occurs through four processes:

* Abrasion- A sand paper effect, where materials rub along the bed and banks of the river causing them to erode. This process is more effective during times of flood and is the major method by which the river erodes both vertically and horizontally.

* Corrosion/ solution- A chemical reaction that happens between rock and the water e.g. the concentration of carbonic acid and humic acid. This happens continuously and is independent of river discharge and velocity

* Attrition- This is the erosion of the bedload of itself. Boulders collide with other materials causing them to break and become smaller and rounder in appearance.

* Hydraulic Action- Due to the force of the river, water is forced into cracks along the river bed. The air in t

he cracks is compressed therefore pressure increases and in time the bank will collapse. This is the

Sorry, but full essay samples are available only for registered users

Choose a Membership Plan
slowest and least effective erosion process.

Depositional Processes

Deposition is where the velocity of a river looses its energy and is no longer able to carry it’s load Material is deposited, starting with the largest particals.

Deposition occurs when:

* Discharge is reduced following a period of low precipitation.

* Velocity is lessened on entering the sea or a lake

* shallower water occurs on the inside of a meander

* the load is suddenly increased (caused by an increase in farming or a landslide)

* the river over flows its banks so that the velocity outside the channel is reduced ; resulting in a floodplain.

Transportation Processes

This is where excess energy is used to transport material down the river. As the velocity and turbulence increases, so does the ability to entrain materials.

The load is transported by three main processes.

* Bedload- This is where larger particals, which cannot be picked up by the current, are transported along the river bed. they are inturn transported in two ways: Saltation, where pebbles, sand and gravel are temporarily lifted up by the current and bounced along the bed in a hopping motion and Traction where cobbles and boulders are rolled along the bed. The very large material may only be moved at times of flood.

* Suspended load- This is where very fine particles of clay, silt and sand are carried by the turbulence of the river. The higher the velocity the bigger the particle that can be entrained. The suspended load is what gives the river its brown, black colour.

* Dissolved or solution load- This is where soluble rock such as limestone is dissolved and removed in solution by the constant running river.

Explanation of factors affecting a river.

* Basin size, shape and relief- If a drainage basin size is small, round and steep sided, rainfall will reach the river more quickly decreasing lag time and increasing velocity.

* Intensity of precipitation- The heavier the rainfall, the more saturated the ground will become therefore, not only will river fill up more quickly due to the heavy rainfall, but water will also flow faster to the river as surface runoff.

* Temperature- Extremes of temperature can restrict infiltration and so increase surface runoff. If evapotranspiration rates are high then there will be less water available to flow to the main river.

* Land use- Urbanisation- Has an increased flood risk due to water being unable to infiltrate through the tarmac or concrete. Farming- Over cultivation of the land surronding a river may mean that tyhe soil is more easily eroded causing a build up of silt in the river and an increased risk of flooding. The loss of vegetation may also mean a higher flood rate as water will flow more easily through the soil. .

* Vegetation- Large amounts of vegetation inhabiting the river, its banks and bed effects its velocity and therefore the amount of erosion.

* Relief- A higher relief will mean that materials will flow faster down the river.

* Geology

How rivers work

Precipitation ( River Basin Characteristics ( River Channel Characteristics

-Relief, Shape, vegetation – Depth, width, velocity, relief,

land use, Geology and soils, efficiency

River Flow

Energy

Equation = 1/2 mv �

( Erosion

River Processes ( Deposition

Transportation

River Load River Features

– Oxbow lakes

– Deltas

We can write a custom essay on

The River Investigation Essay Sample ...
According to Your Specific Requirements.

Order an essay

You May Also Find These Documents Helpful

The Healthiness of the Salt River

Design Objective/Teacher's Instructions: Assess the health of the river by collecting organisms in the river, classifying and correlating them with the chemistry of the river Hypothesis: If there is a high frequency of low-tolerance/sensitive organisms and the chemistry of the river support the frequencies then the Salt River is healthy, but if there proves to be a higher frequency of high-tolerant organism, and being supported by the chemistry results, it therefore states that the river is unhealthy. Independent Variables: * The Macro organisms caught * The chemistry of the river Dependant Variables: * Health of the Salt River Controlled Variables: * The specified site areas to be used for the collection of the organism Uncontrollable Variables: * Time of the season/year * Time of the day when the experiment was conducted * The time of appearance of the organisms * Water tide level * Water flow Apparatus: * Swimming attire...

Credit River Abiotic Feature Study

Introduction The Credit River is an open freshwater system that flows through a predominantly agricultural sector of southern Ontario. The river is approximately 1,500km long and drains into Lake Ontario at Port Credit. Due to urbanization, lower sections of the river have experienced reduced water quality but still remains to attract a variety of species. Research Question What are the physical and biological components that influence biotic life with regard to abundance and Diversity in the freshwater habitat of the Credit River? Hypothesis Relationships between abiotic components will be investigated in this fresh water ecosystem. The main abiotic characteristics in the Credit River that will be explored include; oxygen reduction potential, depth and temperature. Furthermore, abiotic limiting factors such as seasonal differences will be evaluated and discussed. As a result, I hypothesize that quadrants with high oxygen reduction potentials will be colder. Another abiotic factor that will influence the temperature...

Ballybay River Study

Aims and Objectives - The Ballybay River Study has introduced six new fieldwork techniques. These tasks were to measure the width and depth, wetted perimeter, channel bed gradient, current velocity and bed load of each site. The aims of the study are to work together in a group, each introducing their own knowledge, to help understand, and how to complete each tasks and to understand fully how the river channel changes and why it changes. Our aims are to find if the discharge of the Ballybay River increases downstream, if the river's velocity decreases with distance from the source and the channel efficiency increases downstream. Plus to find out if the following hypotheses matches with the theory - * The discharge of the Ballybay River increases downstream * The river's velocity increases with distance from the source * The channel efficiency increases downstream * The size and shapes of the...

Popular Essays

logo

Emma Taylor

online

Hi there!
Would you like to get such a paper?
How about getting a customized one?