Urbanisation in rural areas - Soil Essentials: Managing Your Farm's Primary Asset - page 141

Water use
Undoubtedly one of the major factors determining location of population centres
is the available water supply, which must meet the needs of the population centre
without the risk of f looding, or lack of water in times of drought. Large dams in
Australia are built on rivers f lowing through highly productive valley land. Some
of this land is f looded by the dam and lost for agricultural use. There is also the
question of safety, as most large dams are built on geological fault lines, and the
largely unknown effect they have on water tables needs to be considered. Options
for future water harvesting schemes may include building reservoirs away from the
river and piping water to them, and to consider larger numbers of smaller dams to
serve local areas instead of fewer large dams serving a big area.
The issue of pollution of water supplies will be significantly increased as
population levels increase, and urban planning will have to find ways to minimise
the effects on water storages and river systems, particularly control of runoff from
urban and agricultural land. The issue of efficiency of water use will become
critically important, and will affect rural and urban areas alike. The planning of
efficient water use will become more and more important over time.
Climate modification
As intensity of land use increases, the option of climate modification by extensive
grid planting of trees to improve the microclimates at the soil surface, by providing
shelter from wind and increasing humidity, could significantly increase food and
fibre production. For this option to be effective, planning needs to be done on very
large areas, with significant lead times to measure returns for effort invested. This
option requires regional planning that involves landholders, and local, state and
federal governments. Benefits would be considerable in the medium-to-longer
term, and are well worth pursuing.
Conflicts of interest
Planning along these suggested lines will raise conf licts of interest, especially
where speculative investments hoping for capital gains on land are involved. The
long-term global capability of supplying food and fibre for future generations must
take precedence over speculative investments, and population growth forecasts
highlight the urgency with which the issue of land use and ownership needs to be
addressed.
In terms of local urban planning, the geographic location of future
urbanisation will have to take into account the soil types to a much greater extent
than at present, as well as all the normal considerations. This may mean that urban