Reconnecting irrigation with the river and ecological function of the catchment CSIRO Sustainable Agriculture Flagship Keith L. Bristow CSIRO Land and Water Townsville, Queensland, Australia
Dec 25, 2015
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
• …….