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によって Finn Campbell 7年前.

401

River Tillingbourne

The text delves into various methods and tools used in geographical data presentation and analysis. It highlights the use of isolines, rose diagrams, and photographs to display cyclical patterns, such as traffic flow in urban areas.

River Tillingbourne

Geog 2

Data Presentation

Isoline
Rose Diagram

Shows cyclical patterns

cars flowing in and out of the city

OS Maps
Describe settlement form, function and land use

Settlement forms

CBD

Inner city

people likely to be working in the CBD

high rise

little green space

terraced housing

high population density

likely to be a lot of transport

main roads

suburbs

offroad parking

houses with garden

smaller population density

higher house price

transport links for commuters

nicer houses

rural urban fringe

Smaller settlements outside of cities

still access city but big longer, slightly less services

rural

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Dispersed

Is where the buildings are spread out and is often found in upland areas

Nucleated

Is where a lot of buildings are grouped together and is often found in lowland areas

Linear

a linear settlement pattern is where the buildings are built in lines and is often found on steep hillsides.

Interpret Contours
Scale
Grid references
Photographs
Can do basic risk assessment
could be out of date

different time of day also

Does not show quantitative data
Qualitative Data
Triangular
comment on what it shows

hard

target characteristics

always a percentage of the same thing, check they add up to 100

if one is far away, could be an anomaly or explain the difference

if dots close together, similar characteristics

Used for representing different types of data

very useful for when 3 sets of data involved

Logarithmic

Cannot show negative data as well as the positive values

Zero cannot be plotted

Difficult to analyse

Easy to make errors plotting

Increased data for smaller values

Useful for plotting rates of change

Wide data range can be displayed

Tillingbourne

Summary of findings
Measured?

Hydraulic Radius

0.2 to 0.8

Gradient

3 degrees to 0.4 degrees

How did it change?

0.21m/s to 0.38m/s

Does conclusion match theory?
How can we improve?

Have more groups take more data from more sites and share

as greater sample size

Primary Data

Increase the amount of sites taken data from

make more statistically significant

reduce impact of outliers and anomolies

Increase amount of data taken at each site

get more accurate averages etc

reduce impact of outliers

HOWEVER AIM FULFILLED

to investigate etc

Data does not completely agree

Therefore not statistically significant

Needs more data samples

Critical value 1

Gradient only 70% significant

Veloicty only 85% significant

As velocity increases so does erosion (lateral erosion atleast)

Explained by increasing channel width

Presentation + Analysis

Shows that data does match Bradshaws model

As distance increases so does velocity and hydraulic radius

Bradshaws model

characteristics change tc

Scatter Graphs
Solution?

Test each scatter against spearmans rank

Disadvantage

TEMPTATION

to create a best fit line that agres with bradshaws even if may not be right

can invalidate research and lead to false conclusion

Spoilt by outliers and anomolies

uncertainty whether trend is fit enough for best fit line

uncertainty

shows max, min

Line of best fit

Shows correlation and trend between data sets

Give a good general view of the correlation between two sets of data

Method of Recording data

Better Method?

Electronic flow meter

Often impellor gets clogged by weeds and silt

Easily movable and assembled

More Accurate

Quick and Easy

Squash Ball

ball slowed down by wind, river bank, reeds, sticks

Sits mostly in water, so should give good impression of velocity

ICT Skills
Subtopic
Spearmans Rank
5 parts of data

Needed 0.80 to be statistically significant

0.77 so not statistically significant yet

Need more samples in order to draw a full conclusion

Offers no explanation for pattern shown

Need a large sample size in order to gain accurate results

Shows correlation

Rs= 0.72= strong positive relationship

Matches line of best fit that showed +ve correlation between velocity and distance downstream

Critical values are very reliable and accessible

Allows to use result to draw to a conclusion

Quick to perform as a statistical test

Allows for comparison of data sets (in terms of significance)

Possible to negate chance as a factor for the trends shown

Test of Significance of Data
Secondary Data
Disadvantages

TIME

time context of secondary data is unknown

Could be incompatible as sets of data is effectively a different stream

Therefore hydraulic radius, velocity, base level may have been different

Advantages

Increased Sample Size

And data can be analysed in the same way

So data sets are very comparable

Focused on same factors of channel characteristics

Source of information taken from other groups that shared locational and theoretical context
Risk Assessment
Mitigation Procedure

Multiplication

If multiple of risk and likelihood was above a certain number then judgement was made as to whether the site is appropriate for recording data

3 Steps

IMPACT+SEVERITY

taken into account if occurred

CHANCE

of occurrence of risks (1-10)

RECOGNITION

listed every potential risk of practical

Minimise risk

avoid WEILS disease by not drink or eating near river

Severity and likelihood rating 1-10 based on locational context
Theoretical Context
Bradshaws Model

Source to mouth: channel characteristics and morphology change

Velocity, Hydraulic Radius increasing

Gradient Decreasing

Locational Context
Accessible

All sites within 30 min drive from school

Open and relatively public areas.

Highest River in Southern England

Good for challenging the THEORETICAL CONTEXT

Aim
Investigate the changes in the channel characteristics along the River Tillingbourne from Source to mouth and confirm the application of Bradshaws Model of fluvial dynamics, with particular reference to velocity.

Why?

The aim creates a Locational and Theoretical context

Sites
Site 4

Abinger Hammer

Shere

0.38m/s

7.2km

Site 3

Crossway Farm

0.31

4.6km

Site 2

Wotton House

0.66

3.3km

Site 1

Site Name

Friday Street

Velocity

0.21

Distance Downstream

1.95km