BRS SEMINAR SERIES PRESENTS: Friday 14 July 2006
New insights into salinity in the Murray Darling BasinMary Colreavy — Natural Resource Management, DAFF
Scott Macaulay and Margaret Allan —Bureau of Rural Sciences, DAFF
Salinity is an important resource issue, with impacts on farm productivity and on the quality of our environment and natural
resources. More information on the sources of salt and freshwater in catchments is needed to better manage the problem. To gain a
better understand of salinity in the Murray Darling Basin (MDB), the Australian Government has provided $20 million for the Bureau of Rural Sciences to manage a series of community stream sampling
and salinity mapping projects across the region. Community based stream sampling investigations across 15
Catchment Management Organisations in the MDB will build a snapshot of salinity across the Basin, while detailed investigations
using airborne geophysical surveys will generate detailed three dimensional models of salinity and water process at a small number of critical sites. These results will be combined with an investigation of the social and environmental history of land use practices which will identify the salinity trends over time associated with land-use
changes and map them against current conditions.
Community Stream Sampling and Salinity Mapping in the Murray Darling Basin
Science for decision makers
Mary Colreavy – DEH
Margaret Allan, Scott Macaulay - BRS
www.brs.gov.au
National Action Plan for Salinity & Water Quality
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$20 million committed to salt mapping across the Murray Darling Basin
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Three stage approach
2) Airborne Geophysical Surveys across priority areas.
1) A network of community based stream sampling projects across the Murray Darling Basin
3) An investigation of social and environmental history of land use practices
Community Stream Sampling in the Murray Darling Basin
Science for decision makers
www.brs.gov.au
www.brs.gov.au
Stream Sampling Objectives
•Community involvement in identification of new areas where salt is being mobilised by surface water
•Collection of standardised and verifiable data
•Development of a comprehensive dataset for surface water salt mobilisation in the MDB
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Community Stream Sampling
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Community Stream SamplingCommunity participation in stream sampling is an effective way of identifying surface water salinity.
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Community Stream Sampling
Community groups will monitor EC of streams from major sub-catchments over the next 2 years.
EC (electrical conductivity) is a measure of dissolved salt in water.
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Outcomes
•Ranking of subcatchments based on salinity of surface water
•Information for decisions on salinity management
•Community access to data using web-based tools
•Community involvement in salinity monitoring and management
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Community Stream Sampling
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Goals
•Increased understanding of surface water salinity in the MDB to inform future management decisions.
•Promote community ‘awareness and ownership’ of the information and engagement with CMOs in the management of any salinity problems.
3D Salt and Groundwater Mapping
Science for decision makers
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AIRBORNE ELECTROMAGNETICS
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EXISTING & PROPOSED SALT-MAPPING AREAS
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MACQUARIE AIRBORNE GEOPHYSICS SURVEY AREA
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Excerpt from fat ducks, fat cattle – fat chance.Sydney Morning Herald 08 July 06
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SALT-MAPPING
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GROUNDWATER RESOURCE ASSESSMENT
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GROUNDWATER RESOURCE ASSESSMENT
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CLAY / SAND MAPPING
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MAPPING THE BLANCHETOWN CLAY
Blanchetown ClayHole
Overlying Sands
Saline Sands
Underlying Sands
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MAPPING THE BLANCHETOWN CLAY
www.brs.gov.au* Sydney Morning Herald 8 July 06
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SOCIAL & ENVIRONMENTAL HISTORY
Looking at the social and environmental history of the area.
Identify key-players, and equip them with the knowledge to manage salinity
Combine expert and local knowledge
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Summary
Salt in the landscape varies, both laterally and with depth.
Only salt mobilized by groundwater is a salinity risk.
Understanding where the salt is, is only part of the problem
Understanding groundwater movement & groundwater / surface-waterinteraction is vital.
No ‘one-size-fits-all’ approach. Ask the right questions and collect data that is fit for purpose
The most powerful tool we have is behavioural change.
www.brs.gov.au* Sydney Morning Herald 8 July 06
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