Geoinformation, monitoring and assessment Environment

Updated October 1998

Land cover and land use

Land Cover Classification System: Classification Concepts and User Manual


by Antonio Di Gregorio (GCP/RAF/287/ITA Africover East Africa Project) and Louisa J.M. Jansen (FAO/SDRN)


Abstract

The developed Land Cover Classification System (LCCS) is a comprehensive standardized a-priori classification system, designed to meet specific user requirements, and created for mapping exercises, independent of the scale or means used to map. Any identified land cover anywhere in the world can be readily accommodated. The classification uses a set of independent diagnostic criteria that allow correlation with existing classifications and legends.

Land Cover Classes are defined by the combination of a set of independent diagnostic criteria, the so-called classifiers, which are hierarchically arranged to assure a high degree of geographical accuracy. Because of the heterogeneity of land cover, the same set of classifiers cannot be used to define all land cover types. The hierarchical structure of the classifiers may differ from one land cover type to an other. Therefore, the classification is designed according to two main phases:

  1. an upper Dichotomous phase where eight major land cover types are distinguished;
  2. a lower Modular-Hierarchical phase where the set of classifiers and their hierarchically arrangement are tailored to the major land cover type.

This allows the use of the most appropriate classifiers and reduces the total number of impractical combinations of classifiers. Because of the complexity of the classification and the need for standardization a software program, of which the beta version has been developed, assists the interpretation process. This will reduce heterogeneity between interpreters and with interpretations over time. Because of the flexible manner in which the classification is set up -creation of classes at different levels of the system and the optional use of modifiers and/or environmental attributes and/or specific technical attributes- and the tremendous number of classes possible, this innovative software program assists the user by selecting the right class going stepwise, that is classifier by classifier. This software program will be available as a stand-alone product as well as integrated into a digital image interpretation software which will allow interpretation of imagery followed by labelling of the mapping units with the land cover classes.

The classification system provides a mutually exclusive Land Cover Class which comprises: (1) a unique Boolean formula (a coded string of used classifiers); (2) a standard name; and (3) a unique numerical code. Both the numerical code and standard name can be used to build an automatically generated Legend with the created classes grouped according to the main land cover categories and their domains according to the level of detail. The nomenclature can be linked to a user-defined name in any language.

Further definition of the Land Cover Class can be achieved by adding attributes. Two types of attributes, which form separate levels in the classification, are distinguished:

  1. Environmental attributes: these attributes (e.g. climate, landform, altitude, soils, lithology and erosion) influence land cover but are not inherent features of it and should not be mixed with "pure" land cover classifiers;
  2. Specific technical attributes: these attributes refer to the technical discipline (e.g. for (Semi) Natural Vegetation the Floristic Aspect can be added, for Cultivated Areas the Crop Type, and for Bare Soil the Soil Type).

All Primarily Vegetated land cover classes take conceptually a consistent physiognomic-structural approach combining the classifiers Life Form, Cover and Height (in (Semi)Natural Vegetation) and Life Form (in Cultivated Areas) with Spatial Distribution. The Primarily Non-Vegetated classes take a similar approach using classifiers which deal with surface aspects, distribution/density and height/depth.

The advantages of the classifier, or parametric, approach are manifold. The developed system is a highly flexible a-priori land cover classification in which each land cover class is clearly and systematically defined, thus providing internal consistency. The system is truly hierarchical and applicable at a variety of scales. Re-arrangement of the classes based on re-grouping of the used classifiers, facilitates the extensive use of the outputs by a wide variety of end-users. Accuracy assessment of the end product can be generated by class or by the individual classifiers forming the class. Any occurring land cover can be accommodated in this highly flexible system, therefore the classification could serve as a universal applicable reference base for land cover that would contribute towards data harmonization and standardization.

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