Case Study: Pickering Beck

Question 1

What is Pickering Beck?

Answer 1

A river in North Yorkshire

Question 2

When does the beck flood in particular?

Answer 2

In the summer, flash flooding

Question 3

Which government scheme was piloted in the town?

Answer 3

‘Slowing the Flow’

Question 4

How much did the 2007 flood cost in damage?

Answer 4

£7 million

Question 5

How many times was the town flooded between 1999 and 2007?

Answer 5

4

Question 6

How far does the beck run for?

Answer 6

29km

Question 7

How does the local relief affect flooding?

Answer 7

The drainage basin has steep relief in the hills of the North York Moors, decreasing time taken to reach the river

Question 8

How does the vegetation at Pickering Beck affect flooding?

Answer 8

Largely moorland shrubs and heather grow in peat bogs which can soak up water preventing runoff and further flooding.
- If water is redirected for agriculture or forestry, peat dries out

Question 9

How does the geology affect flooding?

Answer 9

It consists of Gritstone and Limestone (permeable + porous) allowing water to flow through.
Soil is also soft and sandy, so permeable, slowing lag time

Question 10

Which National Park is the beck located in?

Answer 10

The North York Moors

Question 11

What is diffuse pollution?

Answer 11

the release of potential pollutants (such as nutrients, pesticides, faecal bacteria, or chemicals) from a range of activities that, individually, may have no effect on the water environment, but, at the scale of a catchment, can have a significant effect are lost from the land into local rivers, groundwater, etc.

Question 12

What are some examples of diffuse pollution?

Answer 12

• Fertilisers/ pesticides spread at wrong time / too close to a ditch, river, wetland coastal water, etc
• Cultivating too close to a watercourse - removing the buffer strip increases risk of soil loss or field runoff getting straight into watercourses

Question 13

How have farming practices impacted the river + its water quality?

Answer 13

Farming has lead to diffuse pollution, lowering the water quality

Question 14

Why is the river prone to flooding?

Answer 14

Due to the steep sided valley that the water runs off into the beck

Question 15

What was adopted to mange flooding?

Answer 15

A land management technique instead of hard defences

Question 16

What was constructed at Newtondale?

Answer 16

A large low-level bund to hold/store up to 120,000m3 of water in flood events

Question 17

How has the town impacted flooding?

Answer 17

Impermeable surface increase run off rates

Question 18

What was planted around the river catchment?

Answer 18

19ha of hydrophilic plant such as alder and willow trees to create a natural barrier to flood flows

Question 19

What was constructed at the river catchment?

Answer 19

Large woody debris damns, and natural gullies to help water drain from moorlands into forests

Question 20

Why were no-burn zones established?

Answer 20

As burning has the potential to speed up run off by lowering interception and promoting hydrophobic soil conditions which reduce the river change as it becomes full of debris

Question 21

What has been created in terms of no burn zones?

Answer 21

A 10 metre wide buffer zone along the main watercourse therefore vegetation remains (preventing soil erosion), + interception remains (decreasing flooding risk)

Question 22

How can rainfall in Pickering Beck increase chance of flooding?

Answer 22

• Rainfall in the area is heavy and hydrograph flashy.
• Peak discharge fluctuates as heavy rainfall can result in precipitation arriving too quickly to infiltrate the soil.
• this increases surface run-off leading to water reaching the channel quicker resulting in a greater risk of flooding

Question 23

How many Large Woody Debris Dams have been constructed in Pickering Beck catchment?

Answer 23

129

Question 24

How many heather bale dams have been constructed?

Answer 24

187

Question 25

What are the main land uses in the river catchment area? (4)

Answer 25

Arable crops
Improved grassland
Heather Moorland
Forestry and woodland

Question 26

How much farm woodland has been planted?

Answer 26

15 ha

Question 27

How much did ‘Slowing the flow cost’

Answer 27

£3.2 million

Question 28

What has pastoral farming led to?

Answer 28

Over grazing

Question 29

What is over-grazing?

Answer 29

Animal eat too much of the vegetation

Question 30

What does loss of vegetation do?

Answer 30

Removes a water store as it decreases interception of water and INCREASES run off reducing the lag time

Question 31

How does trampling link to erosion?

Answer 31

It churns up the soil making it easier to erode and be washed away

Question 32

How does trampling link to compacting?

Answer 32

It compacts the soil making it more impermeable and reduces infiltration rates

Question 33

What has drainage caused?

Answer 33

it has reduced catchment’s capacity, decreasing lag time making the hydrograph more flashy

Question 34

What is the size of the drainage basin?

Answer 34

68km2

Question 35

What do the woody debris damns do?

Answer 35

Increase flood storage by rising water levels and slowing the water

Question 36

What are low levels bunds?

Answer 36

Banks

Question 37

What have moorland drains been blocked with?

Answer 37

Heather bales

Question 38

What does blocking drains do?

Answer 38

Encourages natural storage and reduce fast water flowing to river

Question 39

What does Newtondale bund do?

Answer 39

Lowers the flood peak downstream therefore reduces the flood risk

Question 40

Why does Pickering Beck have a flashy hydrograph? (3)

Answer 40

• Very hilly so water can’t infiltrate - gets filled quickly by the relief rainfall.
• High No of tributaries
• Lag time is short as precipitation reaches river quickly