Monitoring Agricultural Drought in Australia - Monitoring and Predicting Agricultural Drought: A Global Study - page 375

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ical perspective. The climate monitoring network, which is the basis for
BoM's drought assessment, also serves as input to a national monitor-
ing system operated by several state government agencies. These systems
are described later in this chapter. Individual state governments also op-
erate official drought declaration schemes that involve monitoring emerg-
ing drought situations at both individual property and district scales. Such
monitoring is largely subjective and based, in the first instance, on the ap-
plications for government assistance by individual property owners. The
process used in Queensland since 1964 is outlined below as an example.

D rought Monitoring at a State Level:
Th e Queensland Example

[375

The Queensland drought scheme primarily aims to assist primary produc-
ers with livestock management during drought. The process for declaring
drought in Queensland begins with an individual primary producer ap-
proaching the local stock inspector for an “individual droughted property”
(IDP) declaration. Following a property inspection by the stock inspector,
a local drought committee assesses the application. If drought conditions
appear widespread and a significant number of IDPs have been issued, the
local drought committee may recommend that the entire district (shire or
part thereof) be declared drought stricken. The state government reviews
the application and, until policy changes in the early 1990s, would declare
drought if summer (October-March) rainfall at official recording stations
in the district was 40% below the long-term average rainfall or, for south-
ern Queensland, if winter (April-September) rainfall was 50% below the
long-term average (Daly, 1994). Since the early 1990s, drought has been
defined as a once in 10- to 15-year event. From this definition, a thresh-
old of annual rainfall below the 7th to 10th percentile has been adopted
as a declaration criterion. This threshold equates to an annual rainfall of
approximately 40% below the long-term average and is therefore similar
to thresholds used before 1964. Drought status is revoked once it is ascer-
tained that stock numbers can return to normal levels. Because the revo-
cation threshold is higher than the declaration threshold, official droughts
have occurred more than 10% of the time.

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R ainfall and Climate Monitoring

BoM monitors rainfall across Australia through a network of approxi-
mately 7000 stations operated largely by volunteers. The National Cli-
mate Center (NCC) receives digital data via phone lines each day from
approximately 300 automatic weather stations and 1500 observers. This
telegraphic network provides the basis for near-real-time assessment of
rainfall and climate. The remaining stations report via regular mail on a
monthly basis. These written records are checked and digitized at the NCC
before being placed on a national database. Data from most stations are