An expert system to predict intricate saline–sodic subsoil patterns in upland South Australia
M. Thomas A B C , R. W. Fitzpatrick A B and G. S. Heinson BA CSIRO Land and Water, PMB 2, Glen Osmond, Adelaide, SA 5064, Australia.
B University of Adelaide, North Terrace, Adelaide, SA 5001, Australia.
C Corresponding author. Email: mark.thomas@csiro.au
Australian Journal of Soil Research 47(6) 602-612 https://doi.org/10.1071/SR08244
Submitted: 3 November 2008 Accepted: 27 May 2009 Published: 30 September 2009
Abstract
Digital soil mapping (DSM) offers apparent benefits over more labour-intensive and costly traditional soil survey. Large cartographic scale (e.g. 1 : 10 000 scale) soil maps are rare in Australia, especially in agricultural areas where they are needed to support detailed land evaluation and targeted land management decisions. We describe a DSM expert system using environmental correlation that applies a priori knowledge from a key area (128 ha) soil–landscape with a regionally repeating toposequence to predict the distribution of saline–sodic subsoil patterns in the surrounding upland farming region (2275 ha) in South Australia.
Our predictive framework comprises interrelated and iterative steps, including: (i) consolidating a priori knowledge of the key area soil–landscape; (ii) refining existing mentally held and graphic soil–landscape models; (iii) selecting suitable environmental covariates compatible with geographic information systems (GIS) by interrogation via 3D visualisation using a GIS; (iv) transforming the existing soil–landscape models to a computer model; (v) applying the computer model to the environmental variables using the expert system; (vi) performing the predictive mapping; and (vii) validation. The environmental covariates selected include: digital terrain attributes of slope gradient, topographic wetness index and plan curvature, and airborne gamma-radiometric K%. We apply selected soil profile physiochemical data from a prior soil survey to validate mapping. Results showed that we correctly predicted the saline–sodic subsoils in 10 of 11 reference profiles in the region.
Additional keywords: digital soil mapping, environmental correlation, expert system, saline–sodic soils.
Acknowledgments
We acknowledge Dr Albert Rovira (CSIRO Division of Soils) who initiated the soil research at the site during the 1980s, which we expand upon. Our thanks go to the Cootes and Ashby families for access to their land. Funding support from the Cooperative Research Centre for Landscape Environments and Mineral Exploration and the South Australian Department for Water, Land and Biodiversity Conservation is acknowledged. Finally we thank Dr Tim McVicar and Brett Thomas, both of CSIRO Land and Water, for valuable early comments, and to the 2 anonymous reviewers.
Bui EN
(2004) Soil survey as a knowledge system. Geoderma 120, 17–26.
| Crossref | GoogleScholarGoogle Scholar |
Cattle SR,
Meakin SN,
Ruszkowski P, Cameron RG
(2003) Using radiometric data to identify aeolian dust additions to topsoil of the Hillston district, western NSW. Australian Journal of Soil Research 41, 1439–1456.
| Crossref | GoogleScholarGoogle Scholar |
Chaplot V,
Walter C, Curmi P
(2000) Improving soil hydromorphy prediction according to DEM resolution and available pedological data. Geoderma 97, 405–422.
| Crossref | GoogleScholarGoogle Scholar |
Cook SE,
Corner RJ,
Groves PR, Grealish GJ
(1996) Use of airborne gamma radiometric data for soil mapping. Australian Journal of Soil Research 34, 183–194.
| Crossref | GoogleScholarGoogle Scholar |
Dale MB,
McBratney AB, Russell JS
(1989) On the role of expert systems and numerical taxonomy in soil classification. European Journal of Soil Science 40, 223–234.
| Crossref | GoogleScholarGoogle Scholar |
Gallant JC, Dowling TI
(2003) A multiresolution index of valley bottom flatness for mapping depositional areas. Water Resources Research 39, 1347.
| Crossref | GoogleScholarGoogle Scholar |
Gessler PE,
Chadwick OA,
Chamran F,
Althouse L, Holmes K
(2000) Modeling soil–landscape and ecosystem properties using terrain attributes. Soil Science Society of America Journal 64, 2046–2056.
|
CAS |
Gessler PE,
Moore ID,
McKenzie NJ, Ryan PJ
(1995) Soil–landscape modeling and spatial prediction of soil attributes. International Journal of Geographical Information Systems 9, 421–432.
| Crossref | GoogleScholarGoogle Scholar |
Hudson BD
(1992) The soil survey as a paradigm-based science. Soil Science Society of America Journal 56, 836–841.
Lagacherie P, Voltz M
(2000) Predicting soil properties over a region using sample information from a mapped reference area and digital elevation data: a conditional probability approach. Geoderma 97, 187–208.
| Crossref | GoogleScholarGoogle Scholar |
Lynn IH,
Lilburne LR, McIntosh PD
(2002) Testing a soil–landscape model for dry greywacke steeplands on three mountain ranges in the South Island, New Zealand. Australian Journal of Soil Research 40, 243–255.
| Crossref | GoogleScholarGoogle Scholar |
McBratney AB,
Mendonca ML, Minasny B
(2003) On digital soil mapping. Geoderma 117, 3–52.
| Crossref | GoogleScholarGoogle Scholar |
McKenzie NJ, Ryan PJ
(1999) Spatial prediction of soil properties using environmental correlation. Geoderma 89, 67–94.
| Crossref | GoogleScholarGoogle Scholar |
Moore ID,
Gessler PE,
Nielsen GA, Peterson GA
(1993) Soil attribute prediction using terrain analysis. Soil Science Society of America Journal 57, 443–452.
Park SJ,
McSweeney K, Lowery B
(2001) Identification of the spatial distribution of soils using a process-based terrain characterization. Geoderma 103, 249–272.
| Crossref | GoogleScholarGoogle Scholar |
Rengasamy P
(2002) Transient salinity and subsoil constraints to dryland farming in Australian sodic soils: an overview. Australian Journal of Experimental Agriculture 42, 351–361.
| Crossref | GoogleScholarGoogle Scholar |
Rengasamy P
(2006) World salinization with emphasis on Australia. Journal of Experimental Botany 57, 1017–1023.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
PubMed |
Thomas M,
Fitzpatrick RW, Heinson GS
(2009) Distribution and causes of intricate saline–sodic soil patterns in an upland South Australian hillslope. Australian Journal of Soil Research 47, 328–339.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Wilford JR,
Bierwirth PN, Craig MA
(1997) Application of airborne gamma-ray spectrometry in soil/regolith mapping and applied geomorphology. AGSO Journal of Australian Geology & Geophysics 17, 201–216.