Demands on soil classification and soil survey strategies: special-purpose soil classification systems for local practical use

Abstract

Classifying soils for a particular purpose involves the ordering of soils into groups with similar properties and for potential end uses. The classification of soil is a terrific conceptual and practical challenge, especially in arid environments. The challenge may spur on, or it may deter scientists or end users with an interest in soils. If a classification system proves to be relevant and user-friendly, it stimulates and encourages further work because it is recognised for its inherent capacity to create order and enhance the useful understanding and mapping of soils. General-purpose, internationally recognised soil classification systems such as Soil Taxonomy and the World Reference Base and other nationally recognised classification systems (e.g. Australian or South African) have proved to be tremendously useful for soil classification and advancing understanding of soils across the world. However, because the use of these general-purpose classifications requires considerable expertise and experience, there is a need for complementary special-purpose classification systems that are specifically tailored, for example, to particular environmental problems, land uses or local regions and that use plain language descriptions for soil types. General-purpose classification systems often lag in the incorporation of new terminologies, for example, classification of acid sulfate soils in the Murray-Darling Basin, Australia, has led to descriptions of soil types with subaqueous properties (submerged underwater), monosulfidic materials and hypersulfidic materials, to enable assessment of environmental risk and management options. In addition, new challenges face general-purpose soil classification systems, especially in response to the following questions most frequently asked by soil users: (1) what soil properties are changing vertically and laterally in landscapes and with time, especially in acid sulfate soils? and (2) what are the most suitable approaches for characterising, monitoring, predicting and managing soil changes for environmental impact assessments, pollution incidents, waste management, product development and technology support? The purpose of this chapter is to address these challenges by presenting new ideas and concepts on how best to predict and solve practical problems by focussing on the development of special-purpose or more technical soil classification systems, which use plain language names for soil types. To demonstrate the critical importance of developing special-purpose technical soil classifications, the following five case studies are presented, which tackle difficult problems involving highly complex issues: (1 and 2) soil and water degradation in large aquatic environments from the River Murray and Lower Lakes region in South Australia (changing climatic and anthropogenic modified environments) and from the Mesopotamian marshlands in Iraq (anthropogenic modified arid environment); (3) acid sulfate soil as a new geochemical sampling medium for mineral exploration; (4) soil damage to the Australian telecommunication optic fibre cable network from shrink-swell soils and soil corrosion; and (5) soil landscape features to assist police in locating buried objects in complex terrain.