Hi Folks,
This is not a statistical question in the narrow sense, but it
has a lot to do with the general question of communication and
sharing of information between Agencies. Also, Warning: I'm
somewhat flying a kite here, and it's long!
No doubt like many, I was somewhat shocked at the news of the
devastating flash floods along the River Rye in North Yorkshire
last night, especially at Helmsley and Hawnby, and relieved that
apparently no-one has even been injured, whereas there could have
been several deaths. The damage, however, has been catastrophic.
It seems from reports that the river was rising to alarming levels
by late evening, and the flood peaked at about 1:30 am.
I was myself already aware in a general way, yesterday afternoon,
of forecasts of severe thunderstorms and heavy rain especially
in the N and NE of England. Indeed, I see from yesteday morning's
Observer that such weather was already forecast overnight.
Acording to today's lunchtime BBC1 News, the cloudburst was due
to very humid air coming up from the South encountering cooler
air coming in from the West, being lifted up, and dumping its
contents. I presume this could have been (and probably was)
forecast by the Met Office.
In the event, it seems that over 40mm of rain fell in a short
time over the basin drained by the Rye, which occupies an area
roughly 20x15km, or 300km^2 and is relatively steep-sided.
That amounts to well over 10^7 cu.m. On an order of magnitude
basis, suppose much of this was supposed to have moved down river
over say 10 hours. That's over 10^6/hour, or nearly 300 cu.m. per
second, on average. If (order of magnitude again) it moved at
5m/sec on average (that's about 12 mph) then you have an average
cross-section of 60 sq.m., so clearly anywhere the river channel
was at all narrow you would have great depth (e.g. a V-shaped
channel with sides at 20 deg above horizonal would have that
cross-section at a depth of 21.8m = 72ft; at 10 deg above
horizontal at a depth of 10.6m = 35ft). And that's just on
average! What about the peaks? Maybe allow a factor of 5 or more
for the fact that I'm somewhat guessing orders of magnitude here:
it's still pretty alarming.
So I dare say that, given a rough estimate of how much rain
was likely to have been dumped over a few hours, together with
expertise on run-off and other relevant hydrology, it would
have been possible to arrive at a risk assessment that deep
and catastrophic flooding in such an area was likely, given
the impending meteorlogical conditions and the topography
of the Rye basin.
The experts on assessing impending meteorological conditions
are of course the Met Office. It is probable that they arrived
at a fairly good assessment, and made it available.
The experts on hydrology and flooding are the Environment
Agency. If they had received timely information about impending
meteorology from the Met Office, they could have run their
computer models for all areas (such as the one in question)
and arrived at predicted flood levels. The natural sequel to
this (assuming that it came out anywhere near the severity
of what actually occurred) would have been to issue immediate
and urgent warnings to all relevant people and agencies: the
local people, the police, the fire and rescue services. This
could have been done several hours in advance of the event
itself.
I don't know whether the agencies got any such warnings, but
it seems from press reports that the people on the spot were
taken by surprise and coped off their own bat as best they could.
Some got the hell out, others got into dire straits and in
some cases were rescued from sinking vehicles by onlookers
swimming out to them. In due course, the emergency services
turned out and took care of the ones who were stuck; but quite
possibly these were alerted by phone calls from the people on
the spot.
It's interesting to look at the Environment Agencies website
under Flood/Floodline. At midday today I found the following
flood alerts (and only these, in all the 484 areas for the
NE of England) for any time this month:
Cod Beck at Thirsk
Status : Flood Warning
Received at 06:33 on 20-Jun-2005
Flood Warning
Previous statuses:
All Clear16:56 on 16-Apr-2005
Flood Warning02:39 on 16-Apr-2005
All Clear13:16 on 23-Oct-2004
Flood Warning21:19 on 22-Oct-2004
All Clear11:30 on 19-Apr-2004
River Rye at Butterwick Bridge
Status : Flood Warning
Received at 06:10 on 20-Jun-2005
Flood Warning
Previous statuses:
All Clear21:17 on 16-Apr-2005
Flood Warning09:33 on 16-Apr-2005
All Clear15:53 on 24-Oct-2004
Flood Warning08:48 on 23-Oct-2004
All Clear11:13 on 14-Aug-2004
North York Moors
Status : Flood Watch
Received at 06:09 on 20-Jun-2005
Flood Watch
Previous statuses:
All Clear09:29 on 04-May-2005
Flood Watch15:02 on 03-May-2005
All Clear08:56 on 18-Apr-2005
Flood Watch22:43 on 15-Apr-2005
All Clear09:58 on 28-Feb-2005
Vale of York
Status : Flood Watch
Received at 06:10 on 20-Jun-2005
Flood Watch
Previous statuses:
All Clear09:30 on 04-May-2005
Flood Watch15:02 on 03-May-2005
All Clear08:57 on 18-Apr-2005
Flood Watch02:32 on 16-Apr-2005
All Clear21:43 on 12-Jan-2005
It is clear that all these flood alerts were placed on the
web site only after 06:00 this morning, several hours after
the worst had happened and even more hours after the situation
was already apparent on the ground.
It's also clear from the "Previous statuses" that we're not
looking at alerts which may have gone out yesterday and have
been updated early this morning, since the most recent
"Previous status" in every case was over a month ago.
So it would seem that, at least as far as their web site is
concerned, the Environment Agency had done damn all about it.
If anyone in the affected area, concerned about possible effects
of weather already forecast by yesterday morning, had looked on
the Floodline web site in the course of yesterday, they would
presumably have seen the normal "No flood warnings in force" message.
So this raises some very serious questions about the Environment
Agency in this affair. They can't deny responsibility for taking
on the role of alarm-raisers: Again on their website one can find:
"Help us to help you
There are two things you need to know to protect yourself
from flooding: how and when
How
We have written several guides on how to protect yourself,
your family and your posessions from flooding. To read
these now, follow the link below to Floodline. Our guides
not only tell you how to protect your home from flooding
by installing DIY products, but also simple steps that will
take only a few minutes. It also encourages people to make
their own emergency flood plans
When
Our Flood Warnings service gives people valuable time to put
their preparations into action, before a flood hits them.
You can sign up to this service by calling Floodline 0845 988 1188
We currently use an automatic telephone calling system to
warn individual households, as well as a loudhailers to
warn larger areas. We are continually increasing the number
of properties which can receive this early warning service,
and soon hope to provide warnings and updates to the public
via SMS, email and fax. All our current flood warnings are
displayed on this web site, via the link below."
So they claim to be able to warn, but apparently they did not.
Of course I cannot say definitely that the EA were unaware,
nor that the were aware but did nothing, since it is possible
that they forewarned the emergency services who themselves
did nothing until the disaster was well under way.
But it does seems likely, on the face of it, that one or other
of these was the case.
It seems to me very probable that the following should be true:
a) The Met Office were able to, and no doubt did, forecast
very heavy rainfall
b) The Met Office were in a position to communicate this to the
Environment Agency in good time
c) The Environment Agency were in a position to receive this
information, and run hydrology models to predict the risk
and severity of flooding in areas likely to be affected
d) The Environment Agency were in a position to issue warnings
to local people and emergency services, and advice to the
people, in good time
Somewhere along the line, this chain broke.
I am reminded of the time, back in January 2003, when areas
around London, especially North of London and in Cambridgeshire,
were suddenly brought to a halt by a few hours of particularly
treacherous snow (fine, blown, and falling on sub-zero surfaces,
causing lorries to slide and block carriageways). Huge numbers
of people spent all night in their vehicles, log-jammed.
It turns out the Highways Agency had failed to pass on the Met
Office prediction that this was on the way to local agencies
responsible for gritting, who therefore did not turn out in time
to grit the roads (by the time it had struck, the gritters could
no longer get to the problem).
The Highways Agency ended up with egg well and truly on their
face that time.
We're looking, therefore, at what seems to be a systemic failure
of "interoperability" between agencies such as the Met Office,
the Environment Agency, the Highways Agency, and so on.
There are "emergency" implications within the remit of all of
these (and others), yet the relevant information which there
should be 24-hour provision for sharing does not seem to get
through. The fact that it was a Sunday should have had nothing
to do with it.
Is this symptomatic of the Information Technology society that
has grown up of late? Other stories of information channels
proving to be inoperative, or the technology falling down,
are rife.
To those who ingored my initial warning, and painfully read
to the end, I apologise. But this is a kite that, personally,
I feel is worth flying, and in so far as we on this list are
concerned with the implications for society of information,
of its proper processing, and of due action based on it,
I would welcome comments!
Best wishes to all,
Ted.
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E-Mail: (Ted Harding) <[log in to unmask]>
Fax-to-email: +44 (0)870 094 0861
Date: 20-Jun-05 Time: 19:08:40
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