Putting the 2015/16 winter

floods in historical context

Alistair Duguid

SEPA

Rainfall New 24 and 48 hour

records in Cumbria

Honister pass had a 1,300 year return period

Most of Scotland had double the average rainfall, and the highest monthly averages on record

River flows Several record peaks in

NW England

3 highest flows ever recorded in England and Wales (>10% higher than previous record)

Eden was c.40 times the normal mean flow, a 1 in 300 year return period

Mean flows for 2015 highest on record for the Clyde, Nith, Tweed, Forth & Tay

December events (CEH)

Don

Flows on The River Don at Parkhill from 1 December 2015 to 2 February

2016

0

100

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Time

Dis

char

ge (

cum

ecs

)

Discharge

Q2

Q5

Q10

Q25

Q50

Q100

Q200

Dee Flows on the River Dee at Woodend for 1 December 2015 to 2

February 2016

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Time

Dis

char

ge (

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ecs

)

Discharge

Q2

Q5

Q10

Q25

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Q100

Q200

Tweed

Flows on the River Tweed at Peebles from 1 December 2015 to 2 February

2016

0

100

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500

600

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900

Time

Dis

char

ge (

cum

ecs

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Discharge

Q2

Q5

Q10

Q25

Q50

Q100

Q200

Lyon

Flows on the River Lyon at Comrie Bridge from 1 December 2015 to 2

February 2016

0

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700

Time

Dis

char

ge (

cum

ecs

)

Discharge

Q2

Q5

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Q100

Tay Flows on the River Tay at Ballathie from 1 December 2015 to 2 February 2016

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Time

Dis

char

ge (

cum

ecs

)

Discharge

Q2

Q5

Q10

Q25

Q50

Q100

Data quality Data here are not finalised

Extreme events require extrapolation to the limit of

the model capability

Low flow gauging will be affected for the coming year

at many stations as new channel forms will require

recalibration of stage-discharge relationships