Topic 6- Rivers

Question 1

Main hypothesis

Answer 1

Width, depth, discharge and velocity will increase travelling downstream from the source

Flood risk for a site around the river will be greater if there is:
More development
Steeper slopes
Impermeable geology

Question 2

Method

Answer 2

Sampling strategy (stratified)
Picked own points so we could access all of them and get better results

Question 3

Quantitative - primary

Answer 3

Measurements fo width and depth (systematic intervals)

- metre ruler, tape measure

Question 4

Cross sectional area =

Answer 4

Width x depth

Question 5

Quantitative - primary

Answer 5

Measurement of velocity using hydroprop impeller

- at 3 points across the river (to get an average)

Question 6

Discharge=

Answer 6

Cross sectional area x velocity

Question 7

Qualitative

Answer 7

field sketch to show main features of both sites and to identify anything that might increase flood risk

Question 8

Secondary data (3)

Answer 8

Flood risk map
Geology map
Land use map

Question 9

Flood risk map

Answer 9

Small area of flood risk compared to the river wey

Slight greater area of land at risk around gomshall

Question 10

Geology

Answer 10

Majority of catchment is permeable so low risk

Question 11

Land use map

Answer 11

Catchment is mainly woodland so low risk
Patches of urban areas e.g gomshall
- this would then increase flood risk

Question 12

Data presentation and analysis

Answer 12

Scatter graph

Field sketch

Question 13

Field sketch

Answer 13

Cross ways farm - less built up
-less flooding
Baigner hammer - surrounded by main street
- more flooding

Question 14

Conclusion

Discharge and velocity

Answer 14

They will increase- proven from scatter graph

Question 15

Conclusion

Flood risk for a site

Answer 15

Will be greater if there is more development, more steeper slopes, more impermeable surfaces
Flood risk greater at abinger hammer - shown by flood risk map as it was more built up shown by land use map and sketch map

Question 16

Evaluation

Measuring depth and width

Answer 16

Hard to keep the tape measure straight

Hard to put the metre ruler on the surface of the riverbed due to the presence of of rocks

Question 17

Evaluation

Measuring the velocity

Answer 17

Hydroprop impeller kept getting stuck - inaccurate results

Other groups further up the river may have changed the results- making the velocity slower from them blocking the stream

Question 18

Evaluation

Field sketch

Answer 18

Only shows the immediate area

May miss something important

Question 19

Evaluation

Secondary data

Answer 19

Too large scale to show localised differences

Question 20

Evaluation

Sampling strategy

Answer 20

Not the fairest way to select sites

Done in winter so could get different results in summer