About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in JEQ

  1. Vol. 39 No. 1, p. 26-34
    OPEN ACCESS
     
    Received: Jan 27, 2009
    Published: Jan, 2010


    * Corresponding author(s): Peter.Caccetta@csiro.au
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/jeq2009.0037

A Methodology to Estimate the Future Extent of Dryland Salinity in the Southwest of Western Australia

  1. Peter Caccetta *a,
  2. Robert Dunnea,
  3. Richard Georgeb and
  4. Don McFarlanec
  1. a CSIRO Mathematical and Information Sciences, 65 Brockway Rd., Floreat, Western Australia
    b Dep. of Agriculture and Food, Bunbury, Western Australia
    c CSIRO Land and Water, Floreat, Western Australia

Abstract

In the southwestern agricultural region of Western Australia, the clearing of the original perennial vegetation for annual vegetation-based dryland agriculture has lead to rising saline groundwater levels. This has had effects such as reduced productivity of agricultural land, death of native vegetation, reduced stream water quality and infrastructure damage. These effects have been observed at many locations within the 18 million ha of cleared land. This has lead to efforts to quantify, in a spatially explicit way, the historical and likely future extent of the area affected, with the view to informing management decisions. This study was conducted to determine whether the likely future extent of the area affected by dryland salinity could be estimated by means of developing spatially explicit maps for use in management and planning. We derived catchment-related variables from digital elevation models and perennial vegetation presence/absence maps. We then used these variables to predict the salinity hazard extent by applying a combination of decision tree classification and morphological image processing algorithms. Sufficient objective data such as groundwater depth, its rate of rise, and its concentration of dissolved salts were generally not available, so we used regional expert opinion (derived from the limited existing studies on salinity hazard extent) as training and validation data. We obtained an 87% agreement in the salinity hazard extent estimated by this method compared with the validation data, and conclude that the maps are sufficient for planning. We estimate that the salinity hazard extent is 29.7% of the agricultural land.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2010. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyAmerican Society of Agronomy, Crop Science Society of America, and Soil Science Society of America