River Exe Flashcards
Where is the River Exe basin
South-west England
How long is the river
82.7km
Where does the river start and finish
Rises in the moorland of Exmoor
Reaches the sea at Exmouth on the south coast of Devon
Area of the catchment
601 square km
What altitude to the peat bogs rise to and what are they used for
514m above sea level
Used for sheep farming and shooting game birds
Main underlying rock type
Sandstones - impermeable
What percentage of the catchment is grassland
67%
Annual rainfall
1295mm
What is the regime of the river like
Would expect it to be flashy due to impermeable underlying rocks however it isn’t
82% is either woodland or grassland so discharge recedes relatively slowly
When were the last major floods in the basin
1960
What are 10% of the houses in the catchment at risk of and what does this provide justification for
1 in 100 year flood
Justifies blocking drainage ditches that have been dug
This keeps water in the upper catchment, not allowing it to enter the river so quickly, becoming flood water
What has been done to the peat since WW2
Large areas of peat have been drained by digging drainage ditches
This meant water entered the river more quickly
Reducing lag time
Increasing flooding risk downstream
What is dried out peat more susceptible to
Erosion
This could cause a water quality issue downstream
