National Land and Water Resources Audit

Western Australian Dryland Salinity Assessment 2000

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Summary

The National Land and Water Resource Audit (NLWRA) identified Dryland Salinity (Theme 2) as one of seven major themes for an Audit of the nation's land, water, vegetation and natural resources. Within this theme, Project 1 was developed to identify the Extent and Impact of Dryland Salinity nationally. This report details the results from work done in Western Australia (WA) to meet the Audit requirements.

The national Audit required a consistent analytical approach across the States and Territories to provide an objective assessment of dryland salinity extent, severity, risks and impacts at the regional level. Knowing how big the problem is now and likely to be in the future, will enable National and State governments, industry and communities to make better informed decisions on policies and investment in management.

This project covered the south west agricultural areas of WA. The overall aim was: ?To report on the extent and impact of dryland salinity in Western Australia and to provide a framework for future Audits.?

For the national Audit, the definition of dryland salinity was taken to be that salinity caused by shallow watertables which result from anthropogenic induced changes in a catchment in which the only water input is from natural precipitation (Nulsen and Evans 1998, unpublished). All analysis is based on groundwater depth and trend and the risk of shallow watertables is derived from these two attributes. As dryland salinity is caused by shallow watertables, the risk of salinity is inferred from the risk of shallow watertables. Not all shallow watertables will be saline.

Given the timeframe of the NLWRA, a requirement was that reporting of the extent and impacts be based on the best readily available data. The agreed data elements to be analysed for Project 1 nationally were groundwater levels and trends from bores and wells monitored over recent years. Future impacts were to be predicted for the years 2020 and 2050.

Click here to download the complete report in.pdf format

Please Note: PDF files are in Adobe Acrobat Version 4.0 format. You will need a copy of an Acrobat Reader  in order to view them. Blind and visually impaired users can view the document using a tool available on-line from Adobe Systems  that converts the.pdf files on the fly to HTML.