Creative solutions to river functioning in a change climate Greg Hales
Projected timeseries of south-west WA winter rainfall Winter rainfall in the south-west corner of WA was, for most of last century, extremely reliable Around the mid-1970s rainfall declined dramatically and has not since recovered This change is expected to continue in most model predictions Source: P. Hope 2006 (Indian Ocean Climate Initiative)
Summary Climate model projections aid our understanding as to how climate may respond to enhanced greenhouse gas concentrations Unknown future greenhouse gas concentrations and climate model uncertainty result in a range of projected climates Temperature projections for WA suggest that continued warming is inevitable Rainfall projections for SW WA are consistent across a range of climate models A drying trend is most likely, particularly during the wettest parts of the year
Today Humans response to CC Lessons from the Natural World Natural Systems Short Water Cycle Agricultural response to drought Guiding Principles River Functioning Management 5 we have to unlearn before we can learn.
Anthropological Response Large areas of complex natural forests and woodlands have been cleared from Australian landscapes to increase run-off into water storages with minimal regards to other impacts on the environment 6 everything that ecologists, scientists and naturalists think is important are externalities to economists.
Natural Systems Native species and ecosystems have a range of strategies to adapt to climate change that have evolved over millions of years but failures also occur Range shifts contraction to places with suitable conditions (refugia) expansion or shift in range as conditions change Changes in phenology changes in behaviour e.g. flowering times, breeding Changes in adaptable physiology dominance of better suited traits Evolution of new species natural selection to exploit new niches Extinction some species disappear 7 We cannot solve the problems of the world using the same technology we used to create them
Making your property sustainable and profitable Guiding Principles: Sustainable elements on your property: Air Sunlight Every plant that grows converts these into a product that manages water. Dew is the purest and most available water on your property. Only a living plant allows you to use it profitably. 8 Ignoring this principle results in the need to: Purchase chemicals, or Exploit soil reserves
Short Water Cycle Research has shown that half the rain that falls on a tropical forest originates from evapotranspiration within the forest itself A large tree transpiring about 400l of water a day has a cooling effect equivalent to a 20KW air-conditioner. Evapotranspiration, which utilises the latent heat of evaporation, can use more than 50% of incoming solar energy, thereby cooling, as well as moistening, the air. Photosynthesis (biomass production), by contrast, uses less than 1% in part, the wider public is mistakenly asking for something from 9 science that it can never deliver: certainty and precise answers to what are ultimately political questions.
10 Agriculture Response to Drought
Agriculture Response to Drought 11 Without water, there is no life. It s just that simple.
History Polish scientist Lhotsky (1834) Describing the Australian chain-of-ponds landscapes:. a phenomenon not to be found - to my knowledge - in any other part of the world.. 20 to 200 feet in diameter.. in an alluvial soil of a rich kind. 12. fed by subterraneous springs. The easy wins have been had. We re now on to a series of problems where there are no easy wins.
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Flood plain alluvium Bedrock Groundwater and saline flows 15
Multiple Problems Flood plain alluvium Bedrock Groundwater and saline flows 16
Bedrock Groundwater and saline flows 17
Multiple Benefits Bedrock Groundwater and saline flows 18
River Functioning Not managed as part of a floodplain More than a drain Need to hold water back in the landscape The definition of stupidity is:- 19 Continually doing the same thing and expect a different outcome
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32 80 days after grazing constant grazing
33 Pasture cropping low cost low impact increases diversity
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Phalaris 70 days after grazing 6200g constantly stocked 150g 35
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38 Production with diversity Future landscapes depend on this
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Some conclusions Drought will become a redundant term as Australia plans for a permanently drier future The inflows of the past will never return Agriculture has a negative footprint and even becoming neutral will be a challenge Its all about management Use natural processes as much as possible» Resilience» Biodiversity» Sustainability Toolbox the public is mistakenly asking for something from science that it can 41 never deliver: certainty and precise answers to what are ultimately political questions.
Thank you Greg Hales Program Manager brs.gov.au David Marsh Peter Andrews (NSF) www.blackwoodbasingroup.com.au www.bestfarms.com.au Phone (08) 9765 1555 Email gregh@westnet.com.au