OSACA

OSACA: Outil Statistique d’Aide à la Cartogénèse Automatique

There is a movement in soil science away from qualitative soil classification toward a quantitative approach based on measurement of soil characteristics. OSACA is a software tool designed to help the researcher in soil science perform soil classification on the basis of the clustering of numerical characterisitics of soil samples. Quantitative grouping of soil layer descriptions into profile classes has not advanced much since the 1960s. Here we tackle the problem from pedological, utilitarian and joint points of view using an application, OSACA, that we have developed for the purpose. The program calculates the taxonomic distances between observed profiles based on layer (horizon) characteristics. Characteristics can be either observed soil properties or layer class memberships. The inter-profile distance is calculated in three ways:

  • Pedological distance focuses on the sequence of layers without regard to layer thickness
  • Utilitarian distance weights the metric according to the layer thickness
  • Joint distance is like utilitarian, but with less layer thickness dependence through pre-scaling of depths

OSACA either allocates profiles to existing classes, or creates a new classification of the profiles. Since the pedological distance seems to be more useful for creating classes for pedogenetic and geomorphic studies, whereas the utilitarian distance may be more useful for environmental applications, we test the three distances for soil taxonomy application and available water capacity prediction by using as input variables, soil attributes, and classifying them into new set of profiles. The methods are described for a set of soil profiles in New South Wales, Australia, leading to a conclusion on the best distance predictor and the best input variables.

OSACA Application - Documentation

  •  Download the OSACA Application. Please follow the guidelines of the User Guide if you want to install it in your desktop.
  • WARNING: If you use OSACA with references, don’t forget (as explained in the user guide) to give a unique ID to the soil horizons (so instead of 1, 2 or 3 put “1.1”, “1.2” or “1.3” for horizons 1, 2 and 3 of profile 1).
  • Download a brief Presentation of how to use OSACA Web Application. Details on how to enter the parameters in slides 12, 13 and 14.
  • Download the User Guide of how to use OSACA Web Application. This User Guide is intended not only to describe the use of the program, but also to document its construction and the various algorithms used.
  • Scientific Background for OSACA and Numerical classification of soil profile data using distance metrics. 
    F. Carré and and M. Jacobson, Geoderma, November 2008 (Article in Press). 
  • Helpdesk: In case of questions or Technical support, send an E-mail to Florence Carre

 

Find below some useful user guidelines:

  • Enter the observation table. A proposed Observation Excel file can be downloaded here (Image 1)
  • If needed, enter the soil types table you want to use (Image 1)
  • Enter the number of horizon classes (Image 2)
  • Enter the number of soil classes you want (Image 2)

Find below some Screen shots: