River Exe Case Study

Question 1

Location

Answer 1

• Devon
• Source is in the hills of Exmoor

Question 2

Physical geography of the upper catchment

Answer 2

• maximum elevation 514m
• minimum elevation 26m

Question 3

Land use in the upper catchment

Answer 3

65% of the catchment is agricultural grassland

Question 4

Geology of the upper catchment

Answer 4

underlain by impermeable rocks

Question 5

water balance

Answer 5

• high rainfall
• low percolation and groundwater flow due to the impermeable rock
• surface runoff accounts for 65% of water balance
• drainage ditches also reduce the amount of soil water storage

Question 6

The Wimbleball reservoir
1) What does it do?
2) How has it impacted the water cycle?

Answer 6

• supplies water to Exeter and East Devon
• regulates water supply throughout the year
• prevents peaks and troughs of river discharge, reducing flood risk

Question 7

Peatlands in Exmoor
1) What was it like in the past?
2) How did it impact the water cycle before the project?

Answer 7

• drainage ditches were previously dug into the peatlands to make the land suitable for farming
• the increased the water flow to the river
• as the peatlands dried out, the carbon that was stored got released into the atmosphere

Question 8

What was the Exmoor Mires Project?

Answer 8

• Blocked previously dug drainage ditches in order to restore water supply to the peatlands

Question 9

give 4 benefits of the Exmoor Mires project?

Answer 9

• improved water quality
• improved grazing and water supply for animals
• increased carbon storage
• more water storage in the upper catchment ensures a steady supply of water throughout the year