Namoi
1973 - 1989
The expansion of irrigated agriculture during the last two decades is
not restricted to the state of Queensland. Changes in technological capability,
market demands and government incentives have encouraged the growth of irrigated
crops and pastures in other parts of the inland. In this next example, from
New South Wales, we can appreciate the considerable expansion of irrigation
into what was once dryland grazing country. The area is part of the Namoi
River floodplains in northern New South Wales. Here the soils are fertile
clays and water is available directly from the Namoi River.
Use your browser to open each image
in a new window to compare them.
This scene records the considerable expansion of irrigation into what
was once dryland grazing country on the Namoi River floodplains in northern
New South Wales. The Difference FCC is easily interpreted using our simple
set of rules and shows clearly the changes in greenness.
In the earliest FCC (29/08/72) we can interpret the patterns
and the colours as representing large paddocks of dry grasslands. There
appear to be few extensive woodlands. The gun metal blue colour of dry grass
is patterned in the east by a tinge of crimson indicating the greening tracks
of a passing thunderstorm.
In the latest FCC (01/08/72), the unmistakable square fields of irrigated
crops can easily be detected. The large regularly shaped clusters of paddocks
have an organised look about them that says "agribusiness" rather
than multiple individual operations.
Re-examine the Qld Central Highlands image. The pattern
of cropping there suggests many individual holdings in contrast to here
on the Namoi River floodplains.
The intensification of agriculture results in a significant boost in productivity.
It incurs costs. In the short term these costs are for the engineering infrastructure
(often paid from the public purse) and the inputs of water, research, fertilisers
and energy. In the longer term, say 50 years, every irrigation scheme in
Australia has had to appeal to the public purse to maintain its existence
against threats such as salinity.
It seems that no society based on irrigated agriculture in a semi arid environment
any where in the world at any time in human history has managed to survive
indefinitely. Most of the great irrigation schemes in this country were
established by government involvement. Most of them still rely on government
subsidy in some form. As a nation, it seems unlikely that we will ever be
able to not subsidise this form of intensive agriculture because irrigation
has been the only successful decentralisation of our national population.
