River Exe Flashcards
What are the physical chartists of the River Exe?
Land flatter in south (26m), max elevation in north 514m
Area - 601km2
What is the geology of the River Exe?
84.4% impermeable, Devonian Sandstones
What is the Land use of the river exe?
67% grassland
15% woodland
Arable farmland
3% Moorland and peat bogs
What is the precipitation of the River Exe?
1295mm
What is the Evaporation +/- soil water storage in the river Exe?
451mm
What percentage does runoff account for in the water balance?
844 mm (65%)
Why is the amount of runoff so high in the river exe catchment area?
The impermeable nature of the most of the bedrock reduces percolation and baseflow
Drainage ditches on Exmoor reduce the amount of soil water storage.
When was the River Hasseoo damed?
1979
What is the surface are of the Wimbleball Reservoir?
150ha surface area, 21.5m cubic metres
What does the Winbleball Reservoir do?
Dry summers, water released to support treatment works downstream
South West Water and Wessex Water provide Exeter and East Devon
Has been released to aid Salmon in migration downstream in the spring
What happened to the peat land in the River Exe?
For decades, fringe ditches have been dug in the peat bogs of Exmoor to make it more suitable for farming.
What have the drainage ditches done to the the catchment area?
This has increased the speed of water flow to the Exe, which rescues water quilty as more silt is carried downstream.
What was the aim of the Exmoor Mires Project?
Restore bogs (mires) by blocking drainage ditches, aim of 2000ha
By 2015 how much of the mires had been restored?
By 2015, 1000ha been restored and 100km ditches blocked,
By 2015 what had happened to the water table and drainage?
Raised water table by 2.65cm.
Reduced water draining away by 2/3
