Topic 2 Flashcards
Advantages and disadvantages SYSTEMATIC
Advantages -
1. It is easy to set up - every 1 km downstream
2. Easier to cover the whole study area/sample.
Disadvantages -
- It is more biased - not all members or points have an equal chance of being selected
- It might be difficult to get to a particular site (think river or coastline)
- Easier to do if you are completing the investigation along a river, road or transect.
Advantages and disadvantages stratisfied
Advantages -
2. It is very flexible and applicable to many geographical enquiries
3. Correlations and comparisons can be made between sub-sets (groups)
Disadvantages -
1. Define your groups first.
2. Depends if you collect enough data for each group
Advantages and disadvantages random
Advantages -
1. Can be used with large sample populations
2. Avoids bias
Disadvantages -
1. Depends on who you can stop or where the places are located.
2. Hard to be representative of the whole area.
Primary v secondary
Strengths
Specific to your investigation
Up to date
Strengths
Cheap
Not time consuming to collect
Weaknesses
Time to set up and trial (pilot study)
Need training - interview
Confidentiality
Success rate (questionnaires)
Weaknesses
Outdated, Irrelevant, Getting access, Trustworthy source
Things for rain gauge accuracy
- The funnel helps to concentrate the water into the container.
- The top of the main container is 30 cm above the ground to avoid rain splashing back in.
- Part of it is buried in the ground to prevent evaporation.
Qualitative v quantitive
Strengths
Large samples can be generalised
A lot of data can be collected quickly and automatically
Strengths
Allows respondents to provide answer to questions like ‘why’ and ‘how’.
Opinions are collected and valued.
Weaknesses
Generalising data can hide interesting
anomalies
Hard to gather opinions
Weaknesses
If interviews have taken place, it is very time consuming to type up and group the data into different categories.
How to measure beach profile
Lay tape measure on beach to create a transect (1)
Poles put at break of slope / at equal distances apart (1)
Poles must be vertical (1)
Poles rest on surface / to equal depth in sand (1)
How to draw beach profile
Put tape measure on beach / poles at bottom and top of beach to create profile / transect line
Measure equal distance / 10 m
Put poles at each end of measured distance
Describe a method to measure wave frequency.
Pick a rock on beach
Count number of waves breaking passing person in specified time
Water pollution steps
Choose sites along the river.
2. Ensure that the meter is in good working order.
Place oxygen meter into the river and wait until the number on the display screen is stable or record the number after a certain period of time.
4. Repeat at two more points at each site so an average can be taken. Write down all results and/or averages on a recording sheet.
5. Repeat again at different sites along the river.
Structure for investigation
Choose at least 10 sites along the river
2. Outline how you will collect the data with equipment.
3. Repeat 3 times at each site to get an average.
4. Write down results on a recording sheet.
5. Repeat at 9 other sites downstream to see if there is a change.
Measuring infiltration
Push pipe into ground
Amount of water poured into pipe / water poured into pipe up to 120 mm
Use scale to measure changing height of water in pipe
Use stopwatch to time until water infiltrates / sinks into ground
How to measure angle of slope of river bed
Measure certain / equal distance
Students hold / put poles at either end of measured distance / at specific distance / 5-10 m away from each other / at break of slope
Put two poles vertically / perpendicular / upright / 90°
Method of measuring velocity of river
Put velocity meter / propeller below surface of river / in river / submerge (1)
Propeller must be facing upstream (1)
Nothing in front of / blocking flow past the propeller / stand behind it (1)
Read / look at digital / velocity reading / display / reading on screen
Repeat
How to use a quadrat to measure results
With two ranging poles create
transect. At each site, put the quadran on the beach.
Count the number of squares with the different types of beach material
Record the data on a recording sheet
Repeat this a different places at each site to calculate the average
How to measure pebbles size at different beaches
At each beach create a transect line, using two ranging poles set at a distance of 10 metres apart.
At a regular distance along the transect (every metre) pick up a pebble. This way the same number of pebbles will be picked up at each site.
Method for measuring pebbles
Measure pebble with tape / ruler / callipers / pebbleometer
Adjust callipers / pebbleometer to hold pebble / put pebble between teeth of callipers / blocks of wood
Measure long axis / longest side / maximum length
How to measure longshore drift
Paint pebbles / using different coloured pebbles
Identify / put a pole at starting point
Put them in the wave swash / backwash zone / where waves break / in sea near beach or shore
Leave them for period of time / one day (more than 3 hours)
Measure distance moved and get average
Describe a fieldwork method to compare how tourists may have polluted the two beaches.
Use quadrat / transect
Count / tally litter / estimate area of oil / sewage coverage / weigh litter
Do count at two / three sites
Do count at end of day / in different seasons
Photographs of types of pollution / polluted areas
Suggest two difficulties of this method of measuring the wetted perimeter of the river channel.
Water / river / current moves tape / fast flowing current so tape won’t stay in place
Difficult to lay tape on uneven rocky bed
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