River Exe Case Study - water Flashcards Preview

AS Geography - Abbi > River Exe Case Study - water > Flashcards

Flashcards in River Exe Case Study - water Deck (10)
Loading flashcards...
1

How long is the River Exe?

It flows for around 80km from Exmoor to Exmouth.

2

How much precipitation does the River Exe receive a year?

1295mm

3

How much area does the River Exe cover?

around 600km2

4

What is kind of rock is situated in the River Exe?

Devonian sandstone. The riverbed is 80% impermeable.

5

What mitigation has been put in place around the River Exe?

Drainage ditches that drain peatlands and reduce soil water storage.

6

Why is there a long lag time?

The land use is almost 70% grassland, 15% woodland & farmland and 3% peat bogs.

7

Wimbleball Reservoir

-River Haddeo dammed to create WR
-surface area of 150 ha
-supplies water to Exeter and parts of East Devon
-Regulates water flow, flattens river regime, reduces risk of flooding or drought

8

Why was there a need for peatland restoration (Exmoor mires project)?

Drainage ditches had been built to make peat bogs suitable for farming. This increased speed of water flow to the Exe and reduced water quality.

9

Issues before the Exmoor Mires Project

- Peat dried out, causing decomposition and the release of CO2 and Methane
- Peat was dug out as fuel, which therefore caused a fast release of CO2

10

Ways in which the Exmoor Mires Project was successful

- Restored peat bogs by blocking drainage ditches, aiming to cover 2000ha
- More water storage in upper catchments, ensuring steady water supply
- Improved water quality as water was moving slower
- More carbon storage as peat bogs were restored to boggy conditions key for keeping in carbon
- Improved opportunities for education, leisure and recreation
- Improved grazing and water for animals