Multicriteria Decision Making, Spatial
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Machine Readable Geographic Data Feature Catalogue
Magik, Smallworld Smallworld Software Suite
Management of Linear Programming Queries MLPQ Spatial Constraint Database System
Manhattan Distance Distance Metrics
Manifold Spatial Data Transfer Standard (SDTS)
Map, Bi-Plot Geographic Dynamics, Visualization And Modeling
Map, Centrographic Timeseries Geographic Dynamics, Visualization And Modeling
Map Data Photogrammetric Products
Map Distribution Data Infrastructure, Spatial
Map Generalization A NNE RUAS Laboratory COGIT, IGN-France, Saint-Mandé, France
Manifold Rules Smallworld Software Suite
Manifolds Smallworld Software Suite
Mantel Test CrimeStat: A Spatial Statistical Program for the
Analysis of Crime Incidents
Map Accuracy Spatial Data Transfer Standard (SDTS)
Synonyms Generalization Definition Map generalization is the name of the process that simplifies the representation of geographical data to produce a map at a certain scale with a defined and readable legend. To be readable at a smaller scale, some objects are removed; others are enlarged, aggregated and displaced one to another, and all objects are simplified. During the process, the information is globally simplified but stays readable and understandable. The smaller the scale, the less information is given per square kilometer. Conversely, the larger the scale, the more detailed is the area mapped for the same map size. For
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Map Overhaul
a given size of map sheet, nearly the same quantity of information is given for different scales, either privileging the density of field information (for larger scale) or the spatial extension (for smaller scale). This process is used both in manual and digital cartography. Main Text Generalisation can be first defined by means of graphical constraints and scale. On a map the information is represented by means of symbols. These symbols are coded representations which ensure the interpretation of the meaning. These symbols have minimum sizes that ensure not only good perception but also the recognition of the symbols and their associated meaning. As an example, a very small black polygon representing a building will be seen as a dot and not a building. In the same way two symbols too close one to another will be seen as a single symbol even if in the real world they represent two different entities. These graphical constraints are called legibility or readability constraints. When represented on a map the graphical objects are not a faithful representation of the entities’ sizes at a given scale but are symbolic representations which maximize communication of information. In order to respect graphical constraints, some objects are enlarged and some are displaced one to another. These geometric distortions are minor at the large scale (1:2,000–1:10,000), common at the medium scale (1:15,000–1:50,000) and frequent and very large at small scales. As an example a 6 m width road represented by a line of 0.6 mm on a map is enlarged 10 times at 1:100,000 and 100 times at 1:1,00
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