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Definition Land cover is the observed (bio)physical cover on the earth’s surface on the earth’s surface. It includes vegetation and man-made features as.

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Presentation on theme: "Definition Land cover is the observed (bio)physical cover on the earth’s surface on the earth’s surface. It includes vegetation and man-made features as."— Presentation transcript:

1 Definition Land cover is the observed (bio)physical cover on the earth’s surface on the earth’s surface. It includes vegetation and man-made features as well as bare rock, bare soil and water surfaces. Classification Concepts

2 Difference between Classification and Legend application of a classification in a particular area Legend is defined as the “application of a classification in a particular area ” (Di Gregorio and Jansen, 1998). Classification Concepts 100% 50% 10% >50m 30m >5m 1 2 3 4... 97 9899100 33 47 78 83 Reference Classification System DEFINED GEOGRAPHIC AREA given scale and data type mapping units derived legend

3 Current a-priori classifications in relation to flexibility Conceptual Basis high level of standardization low flexibility increasing number of classes understandable list of class names enormous list of class names with unclear or too narrow class boundary limited number of generic classes limited number of generic classes adequate number of detailed classes high flexibility low level of standardization By increasing the number of classes in an a-priori system, the problem arises of how a user will find its way. Class boundary definitions are based on very slight differences Class boundary definitions will be clear and classes will contain aggregated land cover types. Flexibility that will allow the accommodation of any occurring land cover.

4 New approach to classification -1- mapability Increasing flexibility while maintaining mapability The classification should be flexible in the sense that it should address the potential for the classification system to describe enough classes to cope with the real world. At the same time flexibility should adhere to strict class boundary definitions that are unambiguous and clear. Basic principle classifiers mapability A land cover class is defined by the combination of a set of independent diagnostic attributes, the so-called classifiers that are arranged to assure a high degree of mapability, i.e. geographical accuracy. Conceptual Basis

5 Dichotomous Phase The initial Dichotomous Phase of LCCS Conceptual Basis Below the Dichotomous Phase is shown consisting of pairs of buttons of which the user can select one at the time. Classifier used: Presence of Vegetation Classifier used: Edaphic Condition Classifier used: Artificiality of Cover

6 Modular-Hierarchical Phase The subsequent Modular-Hierarchical Phase of LCCS Conceptual Basis The sets of classifiers tailored to the major land cover and hierarchically arranged according to mapability (classifiers presented in dark blue).

7 Concept for creation of a land cover class Stepwise selection of classifiers that will generate: Boolean Formulaa string of codes, the so-called Boolean Formula; Standard Class Namea Standard Class Name; and Numerical Codea unique Numerical Code. Conceptual Basis Example “Natural and Semi-Natural Terrestrial Vegetation (A12)” : : Classifiers Used: Boolean Formula: Standard Class Name: Code: Code:Code: Life Form & CoverA3A10Closed Forest20005 HeightA3A10B2High Closed Forest20006 Spatial DistributionA3A10B2C1Continuous Closed Forest20007 Leaf TypeA3A10B2C1D1Broadleaved Closed Forest20095 Leaf PhenologyA3A10B2C1D1E2Broadleaved Deciduous Forest20097 2nd Layer: LF, C, HA3A10B2C1D1E2F2F5F7G2Multi-Layered Broadleaved Deciduous Forest20628 3rd Layer: LF, C, HA3A10B2C1D1E2F2F5F7G2Multi-Layered Broadleaved Deciduous F2F5F10G2 Forest With Emergents20630 With each classifier option selected, the string of codes grows, the class name changes and so does the code.

8 Overview of the software application Classification Module build up legend edit classes create user-defined land cover classes display legend save and retrieve print export FIELD DATA MODULE standardized general field data collection specific field data collection automatic extraction of land cover class from field data saving of field data in synthetic form print and export TRANSLATOR MODULE translation of external classifications into LCCS similarity of external single classes through LCCS comparison of two external classifications through LCCS comparison of two LCCS classes all classifiers and attributes glossary conditions to create land cover classes database of all possible classes including name, code and description images and interpretation database CLASSIFICATION MODULE LEGEND MODULE

9 How to add User-defined Attributes? Land cover classes can be “cloned” in order to add specific user- defined attributes to the standard class. A user may want to further define a classifier and/or attribute already used, or add a new attribute. A standard set of clone options is provided. Legend Module The Type of Clone to be made is selected in this window. The result is a code added to the Boolean code (e.g. (1) in the example above) The user- defined code is specified in this window as well as its meaning.

10 A priori versus a posteriori classification Classification Concepts CONCRETE FIELD SITUATION A PRIORI CLASSIFICATION A POSTERIORI CLASSIFICATION ADVANTAGES : - HIERARCHICAL ORDER - STANDARDIZATION DISADVANTAGES : - IMPLICIT RIGIDITY OF THE SYSTEM ADVANTAGE : - HIGH DEGREE OF FLEXIBILITY DISADVANTAGES : - DEPENDING ON AREA - NO STANDARDIZATION OR HIERARCHICAL ORDER a priori classification Example of a very general a priori classification based on four classes (triangle in black and white and circle in black and white) representing the field situation below. Due to the generalization of the classes, the user is obliged to make the best fit of one of the hundred possibilities in the field into one of the four classes, which may result in selecting a class that does not represent well the actual situation. a posteriori classification Example of a posteriori classification. The classes fit better the actual situation in the field situation but the area described is only a portion of the total.


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