I am absolutely and thoroughly stuck on something the local council has
asked me to look into.

Over the last seven years, the rainfall in this area has been well below
normal for 5 of them. Currently, we are over 300mm short of what we
would normally have expected in that time. Doesn't sound a lot, but it
represents 6 months of normal rainfall.

In 2011 we had just under 400mm, 60% of normal, and the following year,
despite numerous thunderstorms, deluges and flood alerts along the River
Nene, several springs in the area dried up, and have not flowed since.
Result = steams with no water in them, local lakes well below level,
with any pollution entering them not being diluted sufficiently not to
cause problems. One lake lost all its waterfowl in July due to
contamination from fuel oil from a local industrial estate. What I have
found is enough evidence to prove that the ground water levels are
severely depleted, with the water table at least 300mm below what it was
5 years ago.

So I would appreciate it if some of you knowledgeable meteorologists out
there would care to hazard a guess at the following. Having experienced
so many dry years recently, what are the chances of getting some
exceptionally wet ones, with steady and moderate rain to start
replenishing the ground water, without the majority of it disappearing
straight into the rivers as surface run-off? What we need is a lot of
water, and I mean a lot, getting down to that water table as quickly as
possible. Any ideas anyone? We have to make a decision shortly as to
what to do with the lakes - leave them as they are, dredge out all the
****e and see what happens, or fill them in and be done with it. And a
reasonably intelligent prediction on future rainfall might help in that
decision.

jim

a very dry and rainless Northampton

"jbm" wrote in message ...
I am absolutely and thoroughly stuck on something the local council has
asked me to look into.

Over the last seven years, the rainfall in this area has been well below
normal for 5 of them. Currently, we are over 300mm short of what we would
normally have expected in that time. Doesn't sound a lot, but it
represents 6 months of normal rainfall.

In 2011 we had just under 400mm, 60% of normal, and the following year,
despite numerous thunderstorms, deluges and flood alerts along the River
Nene, several springs in the area dried up, and have not flowed since.
Result = steams with no water in them, local lakes well below level, with
any pollution entering them not being diluted sufficiently not to cause
problems. One lake lost all its waterfowl in July due to contamination
from fuel oil from a local industrial estate. What I have found is enough
evidence to prove that the ground water levels are severely depleted, with
the water table at least 300mm below what it was 5 years ago.

So I would appreciate it if some of you knowledgeable meteorologists out
there would care to hazard a guess at the following. Having experienced so
many dry years recently, what are the chances of getting some
exceptionally wet ones, with steady and moderate rain to start
replenishing the ground water, without the majority of it disappearing
straight into the rivers as surface run-off? What we need is a lot of
water, and I mean a lot, getting down to that water table as quickly as
possible. Any ideas anyone? We have to make a decision shortly as to what
to do with the lakes - leave them as they are, dredge out all the ****e
and see what happens, or fill them in and be done with it. And a
reasonably intelligent prediction on future rainfall might help in that
decision.

jim

a very dry and rainless Northampton

Hi Jim, I'm soon to give a public lecture on Dartmoor weather. As part of
that I have been looking into climate change on Dartmoor. At Princetown in
the 20th Century annual rainfall significantly (as revealed by an objective
T test) decreased. In the 21st Century, evidence from Haytor would suggect
that that drying trend has slowed but not reversed. My take on this is that
our climate is slowly getting drier in terms of annual rainfall. Basically I
think you're ****ed!

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

On 29/10/2015 02:08, jbm wrote:
I am absolutely and thoroughly stuck on something the local council has
asked me to look into.

Over the last seven years, the rainfall in this area has been well below
normal for 5 of them. Currently, we are over 300mm short of what we
would normally have expected in that time. Doesn't sound a lot, but it
represents 6 months of normal rainfall.

In 2011 we had just under 400mm, 60% of normal, and the following year,
despite numerous thunderstorms, deluges and flood alerts along the River
Nene, several springs in the area dried up, and have not flowed since.
Result = steams with no water in them, local lakes well below level,
with any pollution entering them not being diluted sufficiently not to
cause problems. One lake lost all its waterfowl in July due to
contamination from fuel oil from a local industrial estate. What I have
found is enough evidence to prove that the ground water levels are
severely depleted, with the water table at least 300mm below what it was
5 years ago.

So I would appreciate it if some of you knowledgeable meteorologists out
there would care to hazard a guess at the following. Having experienced
so many dry years recently, what are the chances of getting some
exceptionally wet ones, with steady and moderate rain to start
replenishing the ground water, without the majority of it disappearing
straight into the rivers as surface run-off? What we need is a lot of
water, and I mean a lot, getting down to that water table as quickly as
possible. Any ideas anyone? We have to make a decision shortly as to
what to do with the lakes - leave them as they are, dredge out all the
****e and see what happens, or fill them in and be done with it. And a
reasonably intelligent prediction on future rainfall might help in that
decision.

jim

a very dry and rainless Northampton

You need to also look into the geology ie the permeability of the
rock/ground associated with the springs, may be a long delay.

On Thu, 29 Oct 2015 08:35:36 -0000, "Eskimo Will"
wrote:

At Princetown in
the 20th Century annual rainfall significantly (as revealed by an objective
T test) decreased. In the 21st Century, evidence from Haytor would suggect
that that drying trend has slowed but not reversed. My take on this is that
our climate is slowly getting drier in terms of annual rainfall.

Our annual rainfall is trending upwards See:-

https://dl.dropboxusercontent.com/u/...009..52.10.png

--
Alan White
Mozilla Firefox and Forte Agent.
By Loch Long, twenty-eight miles NW of Glasgow, Scotland.
Webcam and weather:- http://windycroft.co.uk/weather

Alan White wrote:

On Thu, 29 Oct 2015 08:35:36 -0000, "Eskimo Will"
wrote:

At Princetown in
the 20th Century annual rainfall significantly (as revealed by an objective
T test) decreased. In the 21st Century, evidence from Haytor would suggect
that that drying trend has slowed but not reversed. My take on this is that
our climate is slowly getting drier in terms of annual rainfall.

Our annual rainfall is trending upwards See:-


https://dl.dropboxusercontent.com/u/...2009.52.10.png


Intuitively, that's what I would expect i.e. if some parts of the country have
a trend towards drier weather then others are likely to have a trend towards
wetter weather. Changes to the dominant wind directions are probably the key.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org

On Thursday, 29 October 2015 02:08:50 UTC, jbm wrote:
I am absolutely and thoroughly stuck on something the local council has
asked me to look into.

Over the last seven years, the rainfall in this area has been well below
normal for 5 of them. Currently, we are over 300mm short of what we
would normally have expected in that time. Doesn't sound a lot, but it
represents 6 months of normal rainfall.

In 2011 we had just under 400mm, 60% of normal, and the following year,
despite numerous thunderstorms, deluges and flood alerts along the River
Nene, several springs in the area dried up, and have not flowed since.
Result = steams with no water in them, local lakes well below level,
with any pollution entering them not being diluted sufficiently not to
cause problems. One lake lost all its waterfowl in July due to
contamination from fuel oil from a local industrial estate. What I have
found is enough evidence to prove that the ground water levels are
severely depleted, with the water table at least 300mm below what it was
5 years ago.

So I would appreciate it if some of you knowledgeable meteorologists out
there would care to hazard a guess at the following. Having experienced
so many dry years recently, what are the chances of getting some
exceptionally wet ones, with steady and moderate rain to start
replenishing the ground water, without the majority of it disappearing
straight into the rivers as surface run-off? What we need is a lot of
water, and I mean a lot, getting down to that water table as quickly as
possible. Any ideas anyone? We have to make a decision shortly as to
what to do with the lakes - leave them as they are, dredge out all the
****e and see what happens, or fill them in and be done with it. And a
reasonably intelligent prediction on future rainfall might help in that
decision.

jim

a very dry and rainless Northampton

Hi Jim,
If you look at the record of annual rainfall for Plymouth 1874 to 2014 you see how variable it is with no longterm trend, but clearly trends on the decadal timescale.

You can see an increasing trend after the drought of the mid seventies, and then a decrease and now slight increase again.

I have also put in dropbox the link to the graph of summer and winter rainfall.
There is a significant increasing trend in winter rainfall and a less convincing decrease in summer rain. Hence no trend in annual rainfall over the longterm.

https://www.dropbox.com/s/u0s7p9kroj...02014.jpg?dl=0

https://www.dropbox.com/s/9lfjie7ko4...0rain.jpg?dl=0

If I was you Jim I would hold fire, but if the water usage has gone up in recent years and/or the surface morphology has changed then you are stuck.

Len
Wembury, SW Devon

On Thursday, 29 October 2015 08:35:51 UTC, wrote:

Hi Jim, I'm soon to give a public lecture on Dartmoor weather. As part of
that I have been looking into climate change on Dartmoor. At Princetown in
the 20th Century annual rainfall significantly (as revealed by an objective
T test) decreased. In the 21st Century, evidence from Haytor would suggect
that that drying trend has slowed but not reversed. My take on this is that
our climate is slowly getting drier in terms of annual rainfall.
Will

Hi, Will,
Hmmm, how far north would you be tempted to travel to lecture? NE RMetSoc renowned for looking after their speakers. We had Colin Clark up from Bruton last month.
Here's hoping.

Ken

"jbm" wrote in message ...
I am absolutely and thoroughly stuck on something the local council has
asked me to look into.

Over the last seven years, the rainfall in this area has been well below
normal for 5 of them. Currently, we are over 300mm short of what we would
normally have expected in that time. Doesn't sound a lot, but it
represents 6 months of normal rainfall.

In 2011 we had just under 400mm, 60% of normal, and the following year,
despite numerous thunderstorms, deluges and flood alerts along the River
Nene, several springs in the area dried up, and have not flowed since.
Result = steams with no water in them, local lakes well below level, with
any pollution entering them not being diluted sufficiently not to cause
problems. One lake lost all its waterfowl in July due to contamination
from fuel oil from a local industrial estate. What I have found is enough
evidence to prove that the ground water levels are severely depleted, with
the water table at least 300mm below what it was 5 years ago.

So I would appreciate it if some of you knowledgeable meteorologists out
there would care to hazard a guess at the following. Having experienced so
many dry years recently, what are the chances of getting some
exceptionally wet ones, with steady and moderate rain to start
replenishing the ground water, without the majority of it disappearing
straight into the rivers as surface run-off? What we need is a lot of
water, and I mean a lot, getting down to that water table as quickly as
possible. Any ideas anyone? We have to make a decision shortly as to what
to do with the lakes - leave them as they are, dredge out all the ****e
and see what happens, or fill them in and be done with it. And a
reasonably intelligent prediction on future rainfall might help in that
decision.

jim

a very dry and rainless Northampton

For your interest, I have listed the decade average annual rainfall for
Wokingham since 1885. The driest decade recently was 1985 to 1994, but there
is no indication of a long-term drying or wetting trend here.
Decade Annual Anomaly, compared
ending average with 1885 to 2014 average
1894
618
-29.8

1904
597
-51.4

1914
635
-13.1

1924
685
36.5

1934
623
-25.4

1944
643
-5.2

1954
665
16.9

1964
646
-2.0

1974
700
51.6

1984
671
22.4

1994
614
-33.7

2004
679
31.4

2014
668
20.0



--
Bernard Burton

Wokingham Berkshire.

Weather data and satellite images at:
http://www.woksat.info/wwp.html



---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

"Len Wood" wrote in message
...
On Thursday, 29 October 2015 02:08:50 UTC, jbm wrote:
I am absolutely and thoroughly stuck on something the local council has
asked me to look into.

Over the last seven years, the rainfall in this area has been well below
normal for 5 of them. Currently, we are over 300mm short of what we
would normally have expected in that time. Doesn't sound a lot, but it
represents 6 months of normal rainfall.

In 2011 we had just under 400mm, 60% of normal, and the following year,
despite numerous thunderstorms, deluges and flood alerts along the River
Nene, several springs in the area dried up, and have not flowed since.
Result = steams with no water in them, local lakes well below level,
with any pollution entering them not being diluted sufficiently not to
cause problems. One lake lost all its waterfowl in July due to
contamination from fuel oil from a local industrial estate. What I have
found is enough evidence to prove that the ground water levels are
severely depleted, with the water table at least 300mm below what it was
5 years ago.

So I would appreciate it if some of you knowledgeable meteorologists out
there would care to hazard a guess at the following. Having experienced
so many dry years recently, what are the chances of getting some
exceptionally wet ones, with steady and moderate rain to start
replenishing the ground water, without the majority of it disappearing
straight into the rivers as surface run-off? What we need is a lot of
water, and I mean a lot, getting down to that water table as quickly as
possible. Any ideas anyone? We have to make a decision shortly as to
what to do with the lakes - leave them as they are, dredge out all the
****e and see what happens, or fill them in and be done with it. And a
reasonably intelligent prediction on future rainfall might help in that
decision.

jim

a very dry and rainless Northampton

Hi Jim,
If you look at the record of annual rainfall for Plymouth 1874 to 2014 you
see how variable it is with no longterm trend, but clearly trends on the
decadal timescale.

You can see an increasing trend after the drought of the mid seventies,
and then a decrease and now slight increase again.

I have also put in dropbox the link to the graph of summer and winter
rainfall.
There is a significant increasing trend in winter rainfall and a less
convincing decrease in summer rain. Hence no trend in annual rainfall over
the longterm.

https://www.dropbox.com/s/u0s7p9kroj...02014.jpg?dl=0

https://www.dropbox.com/s/9lfjie7ko4...0rain.jpg?dl=0

If I was you Jim I would hold fire, but if the water usage has gone up in
recent years and/or the surface morphology has changed then you are stuck.



Hi Len, interesting stuff, but I have some questions about the graphs?

1. How consistent was the raingauge site over the years.

My experience of looking at Dartmoor gauges has revealed that just a small
change in location (even a few hundred metres) can make a statistically sig.
difference to rainfall. Cowsic is a case in question, due to changes in
aspect from one side of a valley to another.

2. In the 19th Century rainguage height was not consistent, in fact a lot of
gauges were elevated. Scientifically this was proven to produce lower
rainfalls than rainguages on the ground due to turbulence effects.

In my Dartmoor study I have been very careful to only use data where the
raingauge location has been consistent over the decades and where the height
of the gauge above ground has been consistent. I think that is important.

3. Have you done a statistical Student's T test to measure significance of
the changes, I suspect that they are very sig (esp. winter). but with the
provisos of my points one and two above.

Jim, you need to look at your local area rainfall over the decades too, if
you can of course?

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

Another thing on the geology aspect. Research in neaghbouring areas to
see if springs have suddenly emerged or extra river flow as changes
underground can occur to divert groundwater