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1. Kyeamba Creek 2. Liverpool Plains 3. Billabong Creek 4. Wanilla 5. Axe Creek 6. South Loddon Plains 7. Kamarooka 8. Lake Warden 9. Brymaroo Several Groundwater Flow System (GFS) categories are each represented by at least one well-studied catchment: 
Local flow systems in basaltic fractured rock are represented by the Brymaroo catchment.
Local and intermediate groundwater flow systems in deeply weathered sediments - Wanilla case study.
Local and intermediate flow systems in deeply weathered fractured rock - Kamarooka catchment.
Intermediate groundwater flow systems in weathered fractured rock - Axe Creek catchment.
Intermediate groundwater flow systems in fractured rock - Kyeamba Creek catchment.
Regional groundwater flow systems in Cainozoic alluvial sediment - Upper Billabong, South Loddon Plains, Lake Warden and Liverpool Plains study areas.
Catchment conditions and hydrogeologic processes leading to dryland salinity can, thus, be viewed in the context of the GFS framework. Previous investigations of this type and scope are very limited. Modelling of hydrogeologic parameters from each case study catchment provides pertinent information on likely responses to recharge reduction measures in each catchment type. Thus, for example, small local flow systems have the greatest potential for remediation in a 20 year timeframe through revegetation options (e.g. Kamarooka, Wanilla, parts of Kyeamba Creek, and analogous catchments). Larger scale flow systems generally have higher conductivity and greater throughput of groundwater, particularly in regional alluvial aquifers, thus making the balance between filling and draining more complicated and site specific. Engineering solutions are likely to be more appropriate than reafforestation options. Overall response may take 20-50 years, although with some localised rapid responses (e.g. South Loddon Plains and Billabong Creek). Some catchments carry the legacy of primary salinisation from natural Quaternary climate change cycles, with more recent secondary salinity overprints (e.g. Wanilla and Lake Warden). Other systems are geologically and hydrogeologically complex (e.g. Axe Creek). The latter types of complicated systems can be expected to be relatively unresponsive to simple solutions over any realistic timescales. The findings from the case studies can be used as reference points and 'reality checks' for future work in less well-studied catchments in respective GFS categories. This approach embodies the widest range of diversity of salinity expression, of possible action to mitigate rising water levels and salinisation, and of temporal scales of response. This context is designed to support decision-making for and planning of appropriate and cost-effective measures for the remediation and sustainability of Australia's land and water resources. Transferability Placing other catchments in the context of the case studies available, using appropriate measures or parameters, will greatly assist planning for the future care and treatment of Australia's land resources. |
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| design & production by Talkin' Technical Communications | last updated: April 2002 |