Geography Fieldwork

Geography Fieldwork

1. Aim and hypothesis

   • Aim-To see of the width depth and velocity of the river increases furthher downstream. This is to find out if the textbook are correct or observation of the river upsteam is correct.
   • Hypothesis-The further downstream you trvel the larger the values of the velocity, depth and width of the river.

2. Location

   • The river we were measuring is the River Derwent. This is located in the North York Moors close to Scarborough. We will measure it from its source to the Northern end of Forge valley.

3. Risk Assessment

   • Public Access
     • We had to plan our locations according to the public access as some parts of the land were restricted so we were unable to access this due to it not being public land or the land was to dangerous to access.
   • Hypothermia
     • If we fell into the river and got our clothes wet there was chance of getting hypothermia. Therefore we will teak a spare set of clothes with us to change into if this occurs
   • Weil's disease
     • When putting our hands into the water there is chance of catching Weil's disease, therefore we will take rubber gloves with us to wear, preventing this from happening.
   • Depth of water
     • Some areas of the river msy be too deep to measure and cause our clothes to get wet thefefore we will not measure these locations
   • On going risk assessment
     • During the fieldwork there will be ongoing risks which I will look out for and laert others.

4. Collecting data

   • Primary data
     • This is data that is collected by ourselves using measuring instruments to collect the results for the velocity, width and depth of the river
     • Width-To measure the width we place the poles at the side of the river and using a tape we measured the distance between the poles to provide uswith the width.
     • Depth- To measure the depth of the river we divided the width we had calculated by 11 to give us 10 measuring points across the width. At each of these points we measured the depth from the river bed to where the top of the water came against the meter ruler.
     • Velocity- To measure the velocity we divided the width we had measured into 4 to give us 3 points across the width being 1/4, 1,2 and 3/4. At each of these points we places the flow meter in the river about 3/4 of the way from the river bed and it was placed facing the flow of the rivers current. We timed 1 minute to see how many rotations were made uring this time caused by the flow ofthe river.
   • Secondary data
     • Thos is data that has already been collected by people such as ordinance survey maps and previous investigations. This was used to help calculate our locations and compare results.
   • Limitations
     • Human errors, Public access to some points, Positioning of the flow metre, The depth of the water

5. Sampling methods

   • T o calcultae the points were I should collect my data I used a systematic point sample. I used s systematic sample to follow the river and a point sample to measure the locations at equal points apart to make it more fair. I measured it along a 24km stretch 3km apart giving me 8 points to measure.
   • The points were- Helwath Beck,Jugger Howe, Northern end of Broxa forest, Langdale end, Near Hackness, Northern end of forge valley.
   • Limitations-Public acces to the streams meant that only 6 points could be measured

6. Presenting the data

   • I used a scatter graph to present my data, this was to show the relationship between the 2 sets of data
   • Advantages of this method- Qucik and easy to construct, can plot large amounts of data on one graph, best fit line gives a visual representation,includes all loactions on one piece of presentation
   • Disadvantages-Line of best fit is subjective, degree of correlation is and estimate
   • A cross section map could have been used to present the data however it was rejected because the hypothesis was to relate all changes with the distance downstream and this method could not show them all on one dagram so comparisons was diffucult
   • All of the correlations were positive however they became less positive towards the last 3 points due to the sea cut taking water away which we saw

7. Analysing the data

   • To analyse my data I used Spearmans Rank
   • To do this the dependent and independent variable being analysed has to be ranked with the highest number getting the lowest rank. Then the rank of the 2 variables were taken away from each other to give the difference. This is then squared and totaled to give sigma. These numbers can then be used in the equation to give a number of correlation. Then this can be applied to the table of significance to give a value if significance.
   • Advantages- Quick and easy to calculate, it gives us a number to represent the line of best fit, the strenght of the correlation can be found, it can show the level of significance.
   • Disadvantages-You require at least 10 sets of data, there is no casual relationships, you cant identify any anomalies.
   • All of the points have a 0.01 level of significance apart form location 3 which has a 0.05 level of significance. The last 3 locations has a reduced level of significance as they had water taken away from the by the sea cut which we saw.

8. Further research questions and improvements

   • Look into the size of the bedload as you travel downstream
   • Look at the gradient of the land
   • The land use of the area around the river
   • Get access to and measure the locations we couldn't reach
   • Look at the width, depth and velocity after the sea cut.