Each of the four modules will be discussed in detail regarding its purpose, the options available and the links with other modules of the software.
The purpose of this module is to define a land cover class according to two main phases:
At any level within these Phases the user can ask for the land cover class and store its Boolean formula, numerical code and class name in the module called "Legend."
In the Dichotomous Phase the user can select the major land cover category to which the land cover belongs. There are two ways to proceed through the options, to either:
Having determined the major land cover type (Figure 12), the Dichotomous Phase is completed and the user automatically enters the next phase. A pop-up screen will inform the user of the change of Phase.
If the level of information needed or available to determine a land cover class is very limited, the user can select the appropriate choice(s) in this phase and a land cover class will be defined. This class will consist of a Boolean formula, a standard name and numerical code. This class can be stored in the Legend Module (see Section 5.2). Classes thus defined are broad categories because of the limited number of classifiers used. For more detailed definition of classes the user should apply the classifiers of the Modular-Hierarchical Phase.
The Dichotomous Phase with the classifier options Primarily Vegetated - Terrestrial - Natural and Semi-Natural Vegetation selected.
The Modular-Hierarchical Phase is a phase where the set of available classifiers is tailored to the major land cover type. This means that the type, amount and hierarchical arrangement of classifiers will differ from one major land cover type to an other.
In each module, however, three groups of classifiers and attributes are available and they are always presented in the same hierarchical order. Each type of classifier and attribute is also presented in a different colour on the video screen (Figure 13). A distinction is made between:
Example of the classifiers and attributes of two major land cover types: Cultivated and Managed Terrestrial Areas (A11) and Natural and Semi-Natural Terrestrial Vegetation (A12).
The difference between these classifiers and the attributes is that the land cover classifiers are strictly hierarchically ordered. One cannot skip a classifier and go on to the next one unless this possibility is provided for by the program, as occurs with "Semi-Natural and Natural Vegetation" and "Cultivated Terrestrial Areas and Managed Lands". The user must proceed step-by-step in order to develop the structural-physiognomic concept (see Sections 220.127.116.11 and 18.104.22.168).
The classifiers are also ordered according to their mapability. The classifiers at a high level have a higher mapping accuracy than classifiers from lower levels, which means that they will contribute more to establishing clear and precise boundaries between different land cover classes than will lower-level classifiers. If a classifier cannot be determined, the user can stop.
Definition of the land cover class results in:
Both the numerical code and nomenclature name can be used to automatically generate a Legend (see Section 5.2).
The user will start to identify any land cover class using the pure land cover classifiers. A minimum number of these classifiers need to be determined before the user is allowed to combine these classifiers with any of the attributes. If the minimum requirement for classifiers has been satisfied, the button for proceeding to the environmental attributes will be enabled, as well as the buttons to show the class and save it to the Legend.
The pure land cover classifiers are always presented in blocks in which the choices are mutually exclusive, i.e., the user can select only one option. Even where there are two different levels, a more general level and a more specific level, presented in two rows (e.g., in Life Form "Woody" above "Trees" and "Shrubs" in Figure 14) only one option can be selected. If the user clicks on the button "Woody" followed by clicking on "Trees", the button "Woody" will return to its original, inactive, position.
Example of classifier options at different levels of detail (major land cover type A12 - classifier Life Form with a first general level and a second more detailed level).
There are also options that further modify a classifier option (Figure 15). These are called Modifiers and they immediately follow a classifier option (e.g., in Leaf Phenology for Forbs and Graminoids; "Mixed" above "Perennial" and "Annual;" or in Height for all Life Forms). Modifiers belonging to one classifier option are mutually exclusive. Only after selection of the classifier can a modifier be added. If the user clicks the button of a modifier without having clicked on the appropriate classifier first, a message will pop up to inform the user that the classifier should be selected first.
Example of modifier that further defines a classifier option (major land cover class A12 - classifier Leaf Phenology with modifier options Mixed and Semi-Deciduous).
The use of these modifiers will generate (examples are shown in Figure 16):
The more levels with their classifiers that are used, the more specific becomes the land cover class defined. Choices made at a high level may have implications for the availability of a certain classifier at a lower level. If certain options are no longer valid the buttons are disabled. In this way the user is guided through the program and invalid choices prevented.
Examples of Show Class windows with a land cover class defined in the Natural and Semi-Natural Terrestrial Vegetation major land cover type.
The environmental attributes are not hierarchically ordered and the user is free to add appropriate choices in any order. Use of these attributes further defines the environmental settings in which a land cover unit is found (Figure 17). The options within one environmental attribute are mutually exclusive. Use of attributes will result in:
Example of Show Class window with a land cover class with additional environmental attributes: Landform and
Use of the specific technical attribute will further define the land cover class using the related discipline (e.g., for vegetation, the method of how species were recorded can be specified; for cultivated areas, the crop type can be specified) (Figure 18). Again choices are mutually exclusive. Use of a specific technical attribute will result in:
The user can go through the levels of the Modular-Hierarchical Phase of certain major land cover classes and build up as many classes as needed. These classes can be stored in the Legend Module, described in detail in the next Section.
Example of the use of the Specific Technical Attribute Floristic Aspect.
The main purpose of the Legend Module is to store the land cover classes identified in a hierarchical structure that groups the classes according to the main land cover type. Therefore the Legend usually contains only a subset of the Classification, that is those classes which are applicable in the area (to be) interpreted or mapped.
In addition to providing a hierarchical structure, the Legend also offers capabilities to display, edit and add user-defined attributes to a land cover class. It provides standard descriptions for the classes identified and the classifiers used, and all this information can be exported in various formats.
Because in the Legend the classification is applied to a specific area, Mixed Mapping Units can be formed. A Mixed Mapping Unit can comprise two or three classes from the same major land cover type, or two or three classes from different major land cover types. The order of the classes in a Mixed Mapping Unit reflects the dominance in the mapping unit (see also Section 2.5).
Land cover classes are defined in the Classification Module. A Legend is created by storing these land cover classes in the Legend. To store a class defined in the Classification Module, the "Write Class to Legend" button needs to be clicked on in the Actions Panel of the Classification Module (see Section 4.1), upon which a sub-menu is shown (Figure 19). This sub-menu questions the user whether the class is a "Single or Mixed Unit?" The following choices are available: either
The Help button gives further information on which option to select in case of writing a class to the Legend.
From the Classification Module to Legend: window in which the user has to select whether or not the defined land cover class is part of a Mixed Unit.
In the current classification (and its derived Legend) a Mixed Unit is defined as a mapping unit where more than 25 percent of the dominant cover belongs to another land cover class. The dominant land cover class is always the first class mentioned (e.g., Closed Forest/Herbaceous Fields indicates a Mixed Mapping Unit of forest and fields where the forest is the class covering the bigger portion of terrain (more than 50 percent), while the agricultural fields cover at least 25 percent of the area, but less than 50 percent).
The Mixed Mapping Unit is then stored in the Legend. The user can continue to define other land cover classes or switch to any of the other program modules.
There are two ways to enter the Legend Module, either:
In the Main Menu there is a button which leads the user directly to the Legend Module. However, if no land cover classes have been defined in the Classification Module and subsequently stored in the Legend, the Legend will be empty.
From the Classification Module there is a special button to go direct to the main Legend menu, from where the various options can be chosen, as explained below.
Land cover classes can be "cloned" in order to add some specific user-defined attributes to the standard land cover class selected. This allows the addition of more specific and user-oriented attributes while maintaining a standardized land cover class. The user may want to further define a classifier and/or attribute already used, or the user might want to add a new attribute. A standard set of options is provided (see Figure 20).
Window with the options for definition of the Type of Clone in order to add a User-Defined Attribute.
In order to clone a standard land cover class and add a user-defined attribute, follow the steps below (an example is shown in Figure 21):
Example of Legend User-Defined Attribute within a mixed class.
In Display, the classes contained in the Legend will be displayed in a pre-defined hierarchical structure (Figure 22):
Mixed Mapping Units will be displayed under the Structural Domain Mixed Class under the major land cover type of the first, and therefore dominant, element of the class.
Example of Legend Display.
In Edit, the classes comprising the Legend are displayed, placing the elements composing the class in different boxes.
The numerical code and standard name cannot be edited. These are standard elements of a class and are identical for anyone in the world using the system and defining the same class. These elements help the user to trace which class needs to be edited.
The User's Label and Description are the two boxes in which the user can enter user-defined labels and descriptions. These will be displayed in the Legend - Display once entered.
Two buttons are displayed at the bottom of the screen:
The user is provided with a Standard Description for every class defined in the Classification Module and stored in the Legend. This description gives more insight into the classifiers used and the structure of the class than can be inferred from the standard name alone. User-defined attributes are not incorporated in the Standard Description; for an explanation of those, the Legend - Edit option should be used.
In the Standard Class Description, classes are hierarchically arranged according to the Structural Domains of each Major Land Cover Type (see Box 2), identical to the Legend Display, and the following information is shown:
The Standard Description can be printed by selecting Print from the toolbar at the top of the screen (Figure 23).
Example of the Legend Standard Description.5.2.7 Classifiers Used
In the Display, Edit, Add User-Defined Attribute and Standard Description menu options, the Boolean Formula of the land cover class defined is displayed. The menu option Classifiers Used gives the user the possibility to interpret what these code strings mean, as it presents, under the headings of the major land cover types, the key to the codes used in the Legend (Figure 24).
This explanation will be useful in GIS/database queries where the user wants to re-select the data according to a certain classifier or a group of classifiers. Combining numerical codes and the Boolean formulae allows re-grouping according to user-defined queries.
Clicking on this menu option will not invoke a new screen display but will send the created Legend to the printer. The output appears as described under Display (Section 5.2.3).
This set of options allows the user to Save and Retrieve the legends created and is without exchange facility with other LCCS users. A legend stored in this way can only be retrieved by the same copy of the software application.
Example of Legend Classifiers Used.
Clicking on this menu option will invoke a new screen display offering with four choices. This set of options allows storage of legends in specified formats and allows exchange of legends with other LCCS users on different computer platforms.
This menu's options removes the existing Legend, which can be stored in the Output to window specifying the directory and name. The default name is TLegend.txt and a new Legend can be created as the user is so informed.
This menu option will return the user to the where the user was previously. If the user was in the Classification Module before, new classes can be defined and written to the Legend.
In this module, which will become available in version 2.0, the sample site is described and other relevant information can be stored. These data are automatically classified by being translated into the classifiers, modifiers and attributes of LCCS. The sample site can be described using a minimum dataset, a user-defined set or a full set of items. The minimum data set contains only those items needed to meet the requirement to be able to classify the entry according to the Classification System. If the user-defined or customized option is selected, the user needs to choose from the menu which items will be described. These settings can be saved in a file. It will depend on the objectives of a field survey as to which option will be chosen.
The Field Data Module is designed in such a way that the user does not need to be familiar with the classification concepts. Based on the information observed, the Module will check the various concepts in order to define, for instance, the layering in a vegetation type or the type of cover present.
Existing classifications and legends can be translated into the reference classification. By translating them into the Land Cover Classification System, this system acts as a reference base in which correlation between classifications and/or legends becomes possible.
The Translator Module offers the possibility to:
FAO will coordinate input of translated classifications and legends for the time being. Major current classifications translated into the system will come as standard with the software application or will be provided at a later date.
From the Main Menu the user can go directly to the Field Data Module. This provides a short cut in the event that preliminary classes need to be compared with final classes derived through field observation.
In the Menu, the user will also find an option to return to the Main Menu.
Translation of external classifications and legends into LCCS can be done by using the Classification Module and thus creating a Legend (see Sections 5.1 and 5.2) which can be imported in the Translator Module, or by direct input of external classes. In both cases the Import option will be used.
If the user has created a Legend containing all the classes of the classification or legend to be imported, these classes can be imported in the Translator Module one by one. In the menu of the Import screen (Figure 25), the option Retrieve From Legend should be selected, which displays the screen in which classes from the legend can be imported.
First screen of Import.
The Retrieve From Legend option will open the Legend Export to Translator window. In the box the classes stored in the Legend Module are displayed. How to export a class from the Legend Module into the Translator Module is described below:
If a class consists of two LCCS classes, i.e., a Mixed Class, the procedure is slightly different. The Select as 2nd option should be used immediately after having selected the first class of the mixed unit (Step 2 above). After having completed steps 3 to 6, the option Process Class 2 should be selected, followed by Steps 7 and 8. The components of a Mixed Class have to be defined as single classes in order to recompose the mixed class in the Translator - Import.
This stepwise procedure allows each individual land cover class in the Legend to be exported into the Translator Module.
The second option is to add the classes, one by one, into the Translator Module using the Import screen display and without using the Retrieve from Legend option (Figure 26). A new and unique legend name needs to be added to the existing list and for each class to be imported the user needs to follow the sequence below:
This sequence needs to be completed for any class of the external legend to be imported. By clicking on Close the user returns to the Main Menu of the Translator Module.
Retrieving individual land cover classes from the Legend Module into the Translator - Import facility.
This screen will display the final result of the imported external classification and its translation into LCCS. The user can choose to display according to the order in the original classification or legend, or to display according to the order of LCCS. Mixed Classes will be displayed according to the dominant, and first mentioned, class.
To display an imported Legend, follow these steps:
The similarity of individual external classes to other legends or classifications can be quantified. Select the option Similarity Assessment in the Main Menu. In the screen display the user has to select the reference class with which the other classes will be compared. A number of threshold settings are provided. These values are stored in a table of correspondence in which the following assumptions have been made (see Appendix D):
To make a Similarity Assessment of two classes (an example is shown in Figure 27):
First screen of the Similarity Assessment, in which the reference land cover class is selected and second screen in which a number of options need to be selected.
Once classes have been translated into LCCS, the system can act as a reference base for comparison. Individual classes can be compared at the level of their classifiers and attributes, though only those which are provided by the system; user-defined attributes will not be considered. By selecting the option Comparison of External Classes from the Main Menu, a screen will be displayed showing the translated classification available or legends and their class codes. By selecting a classification by clicking, and a class by clicking, the boxes with Class 1 and Class 2, if appropriate, will be filled. The arrows allow the user to select either of the two classes as the reference class. Selection of a second class of the same classification or legend, or a different one, followed by putting the selected class in the right box of class to be compared allows the user to go on to the next screen where the actual comparison will take place. Clicking on the button OK will bring the user to the comparison screen. Click on Display and it will show the two classes and their classifiers; clicking on the button Compare will activate the comparison. The comparison will take into account all the classifiers of the class to be compared with those of the reference class. The following colours may be displayed:
The same procedure can be followed for comparison of Environmental Attributes, if any, by selecting the Env. Attributes option.
Two classes of LCCS may be compared to one another at the level of the classifiers and attributes used. Such a comparison may be based on a class defined in a preliminary interpretation and the other one derived from field observation. By selecting Comparison of Two LCCS Classes from the Main Menu a screen is invoked in which the Class codes of the two classes to be compared should be typed, or the most recent data entry of the Field Data Module is displayed and the user has to fill the box with the class to be compared. The Reference Class and Class To Be Compared can also be entered manually by typing the correct codes in the appropriate boxes. The same set of screens will thereafter be displayed as described under Comparison of Two External Classes (Section 5.4.3). Figure 28 shows an example of two external classes being compared.
Comparison of two external classes using LCCS as reference classification system.