Water & Carbon Cycles - River Catchment Case Study Flashcards
Where is the River Exe located?
Flows from Exmoor to Exmouth in Devon.
How long is the River Exe?
5.2 miles
Where is the source of the River Exe?
Exehead in southwest Somerset
Where is the mouth of the River Exe?
Exmouth in Devon
What is located at the source of the River Exe?
The Exmoor National Park
Where are there high levels of precipitation on the River Exe?
Higher levels of precipitation near the source than near the mouth
What is the land like on the River Exe?
Mostly low permeability (areas with moderate permeability), have a fissure or intergranular rock formation
What is the water balance of the River Exe?
- High levels of precipitation
- Run-off accounts for 65% of the water balance due to the impermeable nature of the bedrock and the drainage ditches on Exmoor
- High amounts of precipitation absorbed by the peaty moorland soils (Exmoor Mires)
Wimbleball Reservoir
- Completed in 1979
- Contains 374 acres of water
- Reduced water downstream
- On a tributary of the River Exe (River Haddeo)
Why was the peatland of the Exmoor Mires degraded?
- Over grazing
- Peat extraction
- Disturbance from military use
- Nutrient decomposition
How much did the Exmoor Mire Project cost?
Cost £4.5 million to restore 3000Ha of peatland
By how much did the water table rise due to the Exmoor Mire Project?
2.65cm on average
What was the aim of the Exmoor Mire Project?
Aims to restore and rejuvenate the Exmoor Mires by blocking up drainage ditches, enhancing water storage and improving water quality. This facilitates a rise in the water table levels and allows peat to accumulate quicker.
Why is the SW peatland important?
- Provides essential services to the ecosystem
- Essential water and carbon stores: reservoirs, peatlands, soil and vegetation, forests and grasslands
