May 2009 Largely as it was in August
2007
The Bureau definition of a drought has changed from
"acute shortage of water". This old definition was used by the QWC and
applied to the depleted dam. It ignored the hydrological situation ( source
meeting with Minister Hinchliffe and QWC officers 31st January 2009)
********************************************
Initial look at the Bureau's hydrology maps that formed the basis of the
"drought"
The Bureau of
Meteorology is the chief recorder of Rainfall and
other items related to weather. In August 2006, their rainfall maps were my
first observation point. A click on the "drought" heading for the last
three years to July 2006 showed a decile map which grades rainfall from 1
to 10 and recorded that it was
in the category of "lowest on record" for the catchments of the
Dams.
I then clicked on the "percentage" map for
the same period and rainfall to observe how much rain fell. It showed that the catchments had received 80 % of
the long term average 1961 to 1990.
The
diversity of the answers for exactly the same rainfall required
explanation. You will see from the attached e-mail from a Climatologist from the
Bureau of Meteorology National Climate Centre that the two results are compatible.
The Dam catchments had received close to 80% of the long term average and that
80% was the "lowest on record". They later confirmed that District 40
in which the catchments reside is a stable rainfall area and permits this
Statistical aberration.
The deficiency of 20% in both 
catchments
was in the non-summer months which normally create little inflow.
*************************************
May 2009 Additions added
Definition of a drought
In the B.O.M. glossary of terms, Drought is described as
"Prolonged absence of marked deficiency of precipitation (rain).
In "living with drought" the Bureau states that
"Meteorologists monitor the extent and severity of drought in terms of
rainfall deficiency".
Our Leaders have placed before us the Meteorology definition
of a drought. It was contained in the "Decile" map delivered to our
homes in SEQ. "Decile maps" grade rainfall in section 1 to 10
with 1 being the lowest on record and 10 being the highest on
record.
It was used by the QCCCE when documenting the
"drought" to January 2007. The base was on rainfall as no hydrology
report was available at that time distance.
THE LAST TWO YEARS ( to March 2009)
A look at the available maps (in the bureau website) for the last two years reveals
that
APPARENT DEPARTURE FROM METEOROLOGICAL DEFINITION
IN THE LAST TWO YEARS
We are all aware that the definition of a "drought"
is now tied to the dam levels with 60% ( now 74% May 2009) being the end of the "drought".
This is a significant change to a "social expectations and
perceptions" view of a drought.
In my view, departure from the meteorological definition obscures
the underlying reason for the depletion of our dams and as a consequence the view of all
solutions to it.
