• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Interpretation of why average velocity changes with distance downstream

Extracts from this document...


Interpretation of why average velocity changes with distance downstream Hypothesis - I predict that average velocity will increase with distance downstream In order to prove my hypothesis I will use the above graphs and my Spearmans rank result for average velocity, which was +0.63. As velocity is the speed of the water passing a point in one second I will need to firstly look at the way in which the water can speed up. The main factors that will affect this are the cross sectional and the wetted perimeter. As we go further down stream both the width and depth increase, and therefore the cross sectional area will also increase, (as the cross sectional area is calculated by multiplying the width by the depth) and if the cross sectional area increases the wetted perimeter will also increase. As there is a larger wetted perimeter there will be a larger pocket of fast moving in the centre of the river that is not experiencing friction from the bed and banks of the river. Therefore as the rivers wetted perimeter increases with distance downstream the average velocity should also increase with distance downstream. Another factor would be the angle of the riverbed. If I was to ask you would a ball roll faster down a steep slope or down a gentle slope you would you say a steep slope, and yes you would be right. ...read more.


Hydraulic action is the sheer force of the water beating against the bed and banks. These effects will all increase with an increase in discharge, as the water will have more energy.Also the landuse will effect the width and depth as the river will need to widen and deepen to hold the water. The landuse for the river Roe is described in the velocity section of my interpretation. There were a few anomalies one at stop 6 for the depth, this was due to the artificial widening of the river to create a crossing point or ford and another at stop 1 where the width was larger than expected because of braiding and an island. This would be less evident after a flood. The above facts and my spearman's rank result of +0.79, I can therefore see that there is a strong positive relationship between the depth and distance downstream and because the depth increases I also believe that the width will increase with distance downstream. Interpretation to show why the cross sectional area will increase with distance downstream Hypothesis- The cross sectional area will increase with distance down stream. The cross sectional area calculated by multiplying the average width by the average depth. We can see from the width graph that the width increases with distance downstream and also the depth increases with distance down stream. ...read more.


There are two main reasons why the rocks/load will become more rounded, one the velocity and two, erosion in the method of attrition. We know that attrition is when stones/rocks collide and break peaces of each other. So if this is the case it means that the longer (the length of time) they have to collide with each other the greater the chance of all the rough pieces being broken off. This means the further the stones /load travels downstream the longer they will have to collide and therefore the load should get smoother. As we already know the velocity increases with distance which also means the river has more power and is able to carry the load further giving them more time to collide. Also if there is more power the collisions will be harder and will remove more rough edges in a shorter space of time. The results above although expected and correct they will not give an interlay accurate reading. As they are selected from only one area at each stop, there are only 20 samples which is very small and also there will be differences between each persons view of each stone. One could think its angular while another person could think its very angular. With the above graphs and explanation I can clearly see that the load should become smoother with distance downstream. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Hydrology & Fluvial Geomorphology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Hydrology & Fluvial Geomorphology essays

  1. Hydrology and Fluvial geomorphology. (Q&A)

    As these processes of erosion and deposition continue to occur, the outside of the meander is eroded further, more so in the direction of the river flow. i.e. if the river is flowing to its mouth southwards, the southern end of the meander is eroded more.

  2. Study the downstream changes of Loughton Brook.

    river Precipitation Precipitation is rain hail sleet and snow Short-term Storage This occurs after interception on plant leaves and flowers Soil Moisture storage This is when water is stored in the soil and used by plants Surface Run-off Water flows over ground to lakes and rivers Through Flow This is

  1. I am going to study the characteristics of rivers and how they change as ...

    My conclusion to this coursework is that the water depth, the channel depth/width, the wetted perimeter, the discharge, the velocity, and the cross-sectional area would increase after every stream order increases. The pebble size will decrease after every stream order increases.

  2. How does the Efficiency and Cross-Sectional Area of a River Change Down Stream?

    in North Yorkshire where I intended on doing several tests to acquire the data needed to answer my investigation question. I spent the day of the visit collecting the data using methods that can be seen in the methodology table on page 3, fig.

  1. The river Gwaun: Investigating how the course of the river changes from the source ...

    5 19 3 19 2 20 2 20 1 Graphs Averages Site 1 - Angular/Sub-angular (5&4) Site 2 - Moderate (3) Site 3 - Moderate (3) Site 4 - Moderate (3) Description The most common shape(s) of bed load in: Site1are angular and sub-angular with 40% each and 80% (16 samples)

  2. This project will study about the way the river Conwy in north Wales changes ...

    If this too short it will be awkward after a half way through we have to measure the width this is because to make it as a average. DEPTH: To find the depth we have make 5 equally distance points of equal distance.

  1. My hypotheses are:The character of the course of the River Bollin will change along ...

    Take digital photographs, Our teacher used a digital camera to take pictures of each site we visited. Equipment used * Waterproof clothing and suitable footwear * 2 Water depth ranging poles * Clip board with measuring boards, set with graph paper, vertical and horizontal rulers as well as a copy

  2. Geography Coursework: Epping Forest

    The right river cliff is steep and on the left bank there is undercutting due to erosion. There is a large tree root that stops the river cliff overhang from falling into the river but the river cliff will eventually collapse.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work