Hazelrigg Weather Station
IEBS, Lancaster University
A Study of the Autumn 2000 Deluge at Hazelrigg
Water, water everywhere! This has been the story of the autumn around the whole country,
especially in the south-east where some places have had over 200% of their 'normal' rainfall
for the time of year. However, we are not bothered what happens 'down south' but rather how
has Hazelrigg (Lancaster University) fared during the recent deluge that has swept the UK.
The recent wet spell at Hazelrigg began during August 2000 and has continued through to the
winter of 2000.
After all the rain we have been having during the autumn I thought it may
be interesting to see how much has been recorded up at Hazelrigg and how it
compares with previous years data back to 1966.
Year 2000
SEPTEMBER 179.4 mm (Sept. record 231.6mm 1981)
OCTOBER 268.4 mm (1.9mm off Oct record (1967)
NOVEMBER 214.0 mm (Nov. record at Hazelrigg)
DECEMBER 80.0 mm (Up to 12th Dec)
TOTAL AUTUMN RAINFALL (SEP-NOV) = 661.8mm making this year the wettest
autumn on record (1966-2000)
The previous wettest autumn at Hazelrigg was 1980 with 530.6mm.
The wettest day this autumn was 30th Oct. with 48.2mm.
The wettest 10 minute period was on Tuesday 26th September when over 14mm
of rain fell just after 9pm and flooded the campus!
ANNUAL HAZELRIGG AVERAGE RAINFALL = 1036.8mm (1966-1999)
Autumn 2000 = 661.8mm
Thus, 64% of the annual mean has fallen this autumn alone!
The total rainfall so far this year (Jan-Nov. inc.) is 1441.8mm, the
wettest year on record is 1981 with 1394.8mm. This figure has already been
surpassed with still the 2nd wettest month historically to go!
This certainly goes a long way to explain why we
have been experiencing floods in the area. The Met Office calculate an
estimate of soil moisture deficit (SMD) and hydologically effective rainfall (HER) every
week, the higher the SMD the drier the soil. The rainfall during September reduced the SMD
from its average of 90mm for late summer to zero, which meant any additional rainfall, of
which there was
plenty during October and November was HER. So, because most aquifers
are fully recharged through last years rain and a relatively wet spring, almost all this
HER is direct runoff into our rivers. The resulting floods are what we are experiencing,
and if we continue to receive a succession of Atlantic lows across the UK we can expect
regular flooding events until next spring when the soil finally starts to dry out! In addition,
the situation has been compounded by the rising levels of already record high water
tables which is causing
flooding from below ground in certain properties.
Keep the wellies and brolly handy!
And just to cheer you up it is still raining well into December...!
Phil Leigh 10th Dec 2000.
[
Department Home page |
Hazelrigg Page |
