River Exe Flashcards
Where is the River Exe
The river exe flows for 82.7m from its source in the hills of Exmoor, through Tiverton and Exeter, to the sea at Exmouth on the South coast of Devon.
Maximum elevation
514M
Lowest elevation
26M
What percent of land is impermeable
84.4%
What impermeable rock is most prominent
Devonian Sandstone
What percent of land os agricultural
67%
What percent of land is woodland
15 percent
What percent of the water balance does runoff account for for
65%
2 main reasons for high runoff
-impermeable nature of bedrock
-drainage ditches in Exmoor
2 main human developments
- the construction of wimbleball reservoir
-the restoration of peat;and on Exmoor
Wimbleball reservoir
In 1979 , the river haddeo, an upland tributary of the river exe was dammed to create wimbleball reservoir
Area of wimbleball reservoir
150 hectares
What does the reservoir do
- the reservoir supplies water to Exeter and parts of East Devon, ensuring a steady flow regime during the year. This prevents the peaks and troughs of water discharge that make flooding or drought more likely.
Peatland restoration on Exmoor
For decades, drainage ditches have been dug in the peat bogs of Exmoor to make it suitable for farming. This has increased the speed of water flow to the exe, which reduces water quality as more silt is carried downstream.
Why has peat been dug
For fuel. As the peat surface has dried out, decomposition has occurred, realign carbon dioxide.
What does the Exmoor mires project do
Works to restore the peat bogs by blocking the drainage ditches with peat blocks or moorland bales. This increases water content and returns the ground to tje saturated, boggy conditions that would naturally occur.
How many hectares of land does the EMP aim to restore
2000ha
By 2015 how many ha of peat moorland had been restored and how many km of drainage ditches blocked
1000ha of peat moorland restored and nearly 100km of ditches blocked
