Geog 2

Sites

Site 1

Distance Downstream

1.95km

Velocity

0.21

Site Name

Friday Street

Site 2

Distance Downstream

3.3km

Velocity

0.66

Site Name

Wotton House

Site 3

Distance Downstream

4.6km

Velocity

0.31

Site Name

Crossway Farm

Site 4

Distance Downstream

7.2km

Velocity

0.38m/s

Abinger Hammer

Shere

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

Locational Context

Highest River in Southern England

Good for challenging the THEORETICAL CONTEXT

Accessible

All sites within 30 min drive from school

Open and relatively public areas.

Theoretical Context

Bradshaws Model

Source to mouth: channel characteristics and morphology change

Velocity, Hydraulic Radius increasing

Gradient Decreasing

Risk Assessment

Severity and likelihood rating 1-10 based on locational context

Mitigation Procedure

Minimise risk

avoid WEILS disease by not drink or eating near river

3 Steps

RECOGNITION

listed every potential risk of practical

CHANCE

of occurrence of risks (1-10)

IMPACT+SEVERITY

taken into account if occurred

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

Secondary Data

Source of information taken from other groups that shared locational and theoretical context

Advantages

Focused on same factors of channel characteristics

Increased Sample Size

And data can be analysed in the same way

So data sets are very comparable

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

Spearmans Rank

Test of Significance of Data

Advantages

Possible to negate chance as a factor for the trends shown

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

Quick to perform as a statistical test

Allows to use result to draw to a conclusion

Critical values are very reliable and accessible

Shows correlation

Rs= 0.72= strong positive relationship

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

Disadvantages

Need a large sample size in order to gain accurate results

Offers no explanation for pattern shown

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

ICT Skills

Subtopic

Method of Recording data

Velocity

Squash Ball

Advantages

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

Disadvantages

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

Better Method?

Electronic flow meter

Advantages

Quick and Easy

More Accurate

Easily movable and assembled

Disadvantages

Often impellor gets clogged by weeds and silt

Scatter Graphs

Advantages

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

Line of best fit

Shows correlation and trend between data sets

shows max, min

Disadvantage

Line of best fit

uncertainty

Spoilt by outliers and anomolies

uncertainty whether trend is fit enough for best fit line

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

Solution?

Test each scatter against spearmans rank

Does conclusion match theory?

Bradshaws model

characteristics change tc

Presentation + Analysis

Shows that data does match Bradshaws model

As distance increases so does velocity and hydraulic radius

As velocity increases so does erosion (lateral erosion atleast)

Explained by increasing channel width

Data does not completely agree

Veloicty only 85% significant

Gradient only 70% significant

Critical value 1

Therefore not statistically significant

Needs more data samples

HOWEVER AIM FULFILLED

to investigate etc

How can we improve?

Primary Data

Increase amount of data taken at each site

get more accurate averages etc

reduce impact of outliers

Increase the amount of sites taken data from

make more statistically significant

reduce impact of outliers and anomolies

Secondary Data

Have more groups take more data from more sites and share

make more statistically significant

as greater sample size

Summary of findings

Measured?

Velocity

How did it change?

0.21m/s to 0.38m/s

Gradient

How did it change?

3 degrees to 0.4 degrees

Hydraulic Radius

0.2 to 0.8

Subtopic

Logarithmic

Advantages

Wide data range can be displayed

Useful for plotting rates of change

Increased data for smaller values

Disadvantages

Easy to make errors plotting

Difficult to analyse

Zero cannot be plotted

Cannot show negative data as well as the positive values

Triangular

Used for representing different types of data

very useful for when 3 sets of data involved

comment on what it shows

hard

target characteristics

if dots close together, similar characteristics

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

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

Photographs

Qualitative Data

Does not show quantitative data

could be out of date

different time of day also

Can do basic risk assessment

OS Maps

Grid references

Scale

Interpret Contours

Describe settlement form, function and land use

Settlement forms

Linear

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

Nucleated

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

Dispersed

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

CBD

Inner city

suburbs

rural urban fringe

rural

`

Subtopic

Smaller settlements outside of cities

still access city but big longer, slightly less services

offroad parking

houses with garden

smaller population density

higher house price

nicer houses

transport links for commuters

high rise

little green space

terraced housing

high population density

likely to be a lot of transport

main roads

people likely to be working in the CBD

Subtopic

Isoline

Rose Diagram

Shows cyclical patterns

cars flowing in and out of the city