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Reconnecting irrigation with the river and ecological function of the catchment
CSIRO Sustainable Agriculture Flagship
Keith L. BristowCSIRO Land and WaterTownsville, Queensland, Australia
Natural capital - Social/cultural capital - Produced capital
It is not about balance – but choices and decisionsNo ultimate trade-off between the economy and environment
Environment Society
Economy ($)
BuiltInfrastructure
EcologicalInfrastructure
Complex inter-connected systems
(Area 770 million ha; Population 22 million)
“SUPPLY”
DEMAND
Pressure for protection and ‘sustainable’ use
Pressure for repair and ‘sustainable’ use
Great B
arrier Reef
Tropic of Capricorn
Brisbane
Broome
Carnarvon
Perth
Melbourne
Adelaide
Darwin
Victoria
NSW
Queensland
NorthernTerritory
SouthAustralia
WesternAustralia
Tasmania
Sydney
TownsvilleKarratha
Kununurra
Katherine
MDB
5
4
321
Australia - the big picture
67
The MDB
• ‘Excess demands’ on the environment got the MDB
into trouble…
• Opportunity to re-balance the system… But…
• Still want to drive the system harder and faster!!
The environment
• Does not function as a ‘business’!
• Catchments (ecosystems) reflect water flows – quantity, quality, timing, duration…and a myriad of other processes
• Complex systems characterised by feedback, non-linearities, lags, trigger and tipping points….
• Cautious about applying business/engineering principles; efficiency, growth, factor four improvements, trade offs…
• Need to maintain or reconnect irrigation with the river and ecological function of the catchment
• Need better understanding of and investment in the ecological infrastructure (elements, systems, services and the inter-connectivity between these)
• Water in the north is already being used- Decisions are about reallocating water to different uses and
understanding the implications
• Groundwater is critical to base flow and maintenance of ecological functions and processes
• Water quality is as important as quantity; especially in meeting ecological needs
• Efficiency is not the answer to everything- Need to meet multiple objectives; water, salt, nutrient …
• All irrigation needs an associated salt management plan
Key take home messages from northern Australia
• Must set and meet water table targets (both quantity and quality) and adjust management practices to meet targets
• Water management is an individual and collective responsibility
• Need policies and management systems that make sense for northern tropical environments (event driven systems)
• Short term economic gains are easy – it is the long-term sustainability that is the real challenge
Key take home messages from northern Australia
Complex interconnected systemsInland Coast
RIVERTurbid waters
Water spreading
Rootzone
Salt & nutrientbalance
SalinitySodicity
RisingGW
soil typeimpacts
ET
Salt water intrusion
Irrigation
GWdepletion
Irrigation
unsaturatedzone
Bores
ETRain
Leakageto sea
Drainagequantity/quality
Rechargepits
Recharge
Recycling
Monitoringwell
runoff runoff
SW / GWInteractions
Sea
Geohydrology and geochemistry impacts
Wetlands
Upwelling
Bores
• Dependent on the river system• Have changed the water and salt balance massively• Must set and meet water table targets (quantity and quality)• Individual and collective responsibility – MUST EXPORT SALT
Surfacewater
Unsaturated zone
Bores
“Contiguous”
RiverCoast
Rainfall ET
Roo
tzon
e
Groundwater system
Uns
atur
ated
zon
e
Surfacewater
Unsaturated zone
Bores
“Contiguous”
RiverCoast
Rainfall ET
Roo
tzon
e
Groundwater system
Uns
atur
ated
zon
e
Traditional largescale irrigated area
“Patchiness”
River
Bores
Groundwater system
Unsaturated zone
Coast
Surfacewater
Rainfall ET
Roo
tzon
e
Uns
atur
ated
zon
e
“Patchiness”
River
Bores
Groundwater system
Unsaturated zone
Coast
Surfacewater
Rainfall ET
Roo
tzon
e
Uns
atur
ated
zon
e
‘Mosaic’ structure
AdvantagesDisadvantages
?
Irrigation mosaics / agro-ecology
Profile
Catchment
Farmenterprise
Field
State /Region
MechanisticQuantitative
FunctionalQualitative
Scale dependent processes
Specialisation
Integration
BiophysicalBiophysical
Socio-economicSocio-economic
Country
Whole of system approach - System Harmonisation
• Definition: A strategy to improve cross-organisational communication and system-wide management to improve production and environmental outcomes in a whole of catchment context (Khan et al., 2008)
• Integrate science, policy, planning, management and communities...
• Working at the interfaces …environmental-social-economic…groundwater-surface water… land-ocean…
• Collaborative and transdisciplinary approaches
• An ongoing conversation…delivering continual innovation and improvement…
Significant opportunities for improved farm production
• A and D are representative points on the efficiency frontier for the best technologies at a point in time (▬)
• C and F are specific points on new efficiency frontiers for new technologies (---)
• Point B represents a position below the current efficiency frontier use
(Keating and Carberry, 2010)
The MDB
• Need a better long-term ‘engagement’ strategy
• Australian’s are investing considerable money in the MDB…
• All are aware tough decisions are involved…
• Must deliver an environmentally resilient and regenerative system for future generations…
Past technologies
• A and D are representative points on the efficiency frontier for the best technologies at a point in time (▬)
• C and F are specific points on new efficiency frontiers for new technologies (---)
• Point B represents a position below the current efficiency frontier use
(Keating and Carberry, 2010)
Investment framework - Production vs investment ($)
Pathway 1: Improve the agronomic performance of growers
Pathway 2: Encourage growers to adopt risk management practices
Pathway 3: Increase efficiencies of resource use
Pathway 4: Create new production frontiers
Pathway 5: Maintain current production potential
Based on John Dillon, 1977. An Analysis of Response in Crop and Livestock Production (2nd edition), Pergamon Press, Oxford
Involves integrating academic researchers with non-academic participants to research a common goal and create new knowledge, theory and practices
(Strong disciplinary skills working collaboratively with a wide range of stakeholders on complex problems towards a common goal)
Transdisciplinary approaches
The environment
• Biodiversity
• Ecosystem services
• Resilience
Irrigation efficiency – a flawed conceptNeed to be specific about how water used in irrigation
• The consumed fraction (essentially ET), comprising:- beneficial consumption (for the purpose intended or other
beneficial use such as environmental purposes);- non-beneficial consumption such as weeds or resulting
from capillary rise during a fallow period);• The non-consumed fraction, comprising:
- recoverable flows (water flowing to drains and back into the river system for possible diversion downstream, and percolation to freshwater aquifers);
- non-recoverable flows (percolations to saline aquifers, outflow to drains that have no downstream diversions or direct outflow to the ocean)
Key drivers
• ‘Empty’ to ‘full’ world… More with less!!
• Environment, water, food, energy...population…
• Complex inter-connected systems
• Peak oil, peak water, peak…
• Economic growth model…
• Competition (‘vested interest’) vs collaboration
• …….