Carding Mill Valley Flashcards
(13 cards)
Aim
To investigate the changes downstream in the river at Carding Mill Valley
Vertical erosion
When river erodes downwards
Lateral erosion
The river eroding side to side
Risks
Slip, trip or fall, weather, wildlife, medical issues and traffic accidents
Systematic sampling
Identifying sites which are roughly equidistant from each other
Stratified sampling
Selecting specific location to collect data. Can be bias but specific data collected
Random sampling
Where sites/samples are chosen totally randomly. No bias but may be unrepresentative of whole area
How the 10 sites are chosen
Initially by stratify sampling then at large stretches of river then we add some sites via a systematic approach (measured roughly every 250m)
To measure depth
Place a meter stick sideways so we can get an accurate result. Put a meter stick into equal spaces across because the river has different depths, this is to measure the cross section.
To measure velocity
Two people stood 5 meters apart in the river. 1 person puts the dog biscuit in the river and let’s go at the same time that another person starts a timer. Measure time of dog biscuit travelling between persons 1 and 2. Do this three times to calculate average. Then use s=d/T to find velocity.
How to find Channelisation’s impact
Measure velocity as normal above channelised section and after the channelised then compare them. This is the best way to do this because you cannot access the river in this section
Width
Increases downstream as a result of lateral erosion and decrease upstream as a result of vertical erosion
Conclusion
Width increases downstream, depth increases downstream, discharge increases downstream and Channelisation by humans increases velocity of the river
