Geography - physical fieldwork

  • Created by: Anne 18
  • Created on: 08-06-18 13:06
What is the title?
How does the Channel Cross Profle and Velocity on the River Holford change with distance downstream?
1 of 29
Why did you chose this title?
This question was chosen as we are studying theoretical channel cross profiles and what happens to velocity in Rivers, so it is sensible to test if it is true in real life.
2 of 29
What is the sub question based on the interrelationship between the physical and human?
What is the impact on cahnnel cross profile and velocity where human intervention has taken place?
3 of 29
What is the source of the River Holford?
It's source is at Lady's fountain - in a wooded, steep valley.
4 of 29
What is the length of the River Holford?
The entire length of the river is only 7.2kms long.
5 of 29
Why is it important to take samples over the course of one day?
This is important when looking at velocity, as rainfall overnight or another dry day will affect the amount of water in the channel, the speed of the water and where the bedload is situated within the channel.
6 of 29
Why is the River Holford a suitable study area?
The river is a suitable study area as the gradient genrally decreases with distance downstream - so we can compare this to how velocity changes. It also has a variety of land uses and changes in the valley shape, including geology.
7 of 29
What wuld we expect to see on the Bradshaw model, based on what we measured?
Based on what we will measure, we would expct to see the river getting wider, deeper, less steep and faster with distance downstream.
8 of 29
State the risks in the risk assessment?
Traffic, steep and rocky footpath, fast river flow, ticks and damage to environment.
9 of 29
How could you minimise the risk of the damage to the environment?
Bring back lityter to recycle, shut gates, tread carefully.
10 of 29
What is a secondary method you used?
Location maps, using Digimaps login
11 of 29
How did you measure location maps?
Go onto Digimaps websitee, login, and search for River Holford. Zoom in to desired view, and copy into a word document - then use a frame tool and textbox with arrows to label the map and draw north arrows.
12 of 29
Why did you use location maps? - justification
It is crucial to know where you are going so that a) you don't get lost and b) you are able to decide where to carry out the other methods. Also, it is useful to use as a base to log where photos are taken.
13 of 29
What are the limitations of location maps?
Time consuming and not all maps have scale bars (less accurate).
14 of 29
What primary methods did you use?
Width, depth, velocity, wetted perimeter, gradiend and fieldsketch.
15 of 29
What equipment did you need to measure velocity?
Advanced flowmeter with hydroprop and impeller.
16 of 29
How did you measure velocity?
1: Stratified to find each site. 2: systematic. Divided by 4 to get 3 points across the river to account for variences in speed - average. 3:Put impeller 1 inch in water, switch on flowmeter for 10 seconds and record data. Wait for 5s, then repeat.
17 of 29
Why did you measure velocity? - justification
To be able to calculate velocity, the average would allow greater accuracy, to answer the title
18 of 29
What are the limitations of measuring velocity?
Leaves in the way, people standing upstream slows flow, impeller getting stuck in shallow areas in debris, not checking that equipment works at the start of the experiment at source.
19 of 29
What is random sampling?
Sampling that has no bias and in which anything has an equal chance of being selected. This will usually involve random number tables as it is not possible to do it complettely random if you slect the sites/ people.
20 of 29
What is systematic sampling?
Samples are taken at regular/fixed intervals, for example every 3rd person that walks by, or measuring a river at every 100 metres.
21 of 29
What is stratified sampling?
Based on knowing something in advance, either about the population of the city or about the river/
22 of 29
How could you extend this study further?
1: go to more points along the river. 2: compare to another river. 3: look at other variable on the Bradshaw model - gradient. 4: as land owners with rivers on land to access more parts. 4: go at different times of year - compare - discharge
23 of 29
How many sites did you measure in you data collection?
10 sites
24 of 29
What did you measure and record at each site?
Width, wetted perimeter, depth, velocity, gradient, annotated fieldsketch
25 of 29
How did depth change with distance downstream?
The deptch increased overall, as expected due to the greater volume of water and energy. Due to tributaries and excess water (ground/rain).
26 of 29
How did the width change with distance downstream?
Width increased form: 170 - 290cm due to having more energy. meaning, attrition increases with increased energy.
27 of 29
How did velocity change with distance downstream?
Velocity increased generally due to a positive corrolation on reference to the scatter graph. Hower site 10 - anomalie due to human intervention (sewage works) - deposition of sediment.
28 of 29
How did gradient change with distance downstream?
The gradent become gentle downstream due to lateral erosion in the middle and lower courses.
29 of 29

Other cards in this set

Card 2

Front

Why did you chose this title?

Back

This question was chosen as we are studying theoretical channel cross profiles and what happens to velocity in Rivers, so it is sensible to test if it is true in real life.

Card 3

Front

What is the sub question based on the interrelationship between the physical and human?

Back

Preview of the front of card 3

Card 4

Front

What is the source of the River Holford?

Back

Preview of the front of card 4

Card 5

Front

What is the length of the River Holford?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Fieldwork resources »