Creating Effective Maps - Cartographic Generalization PDF

Creating E ffective Maps CARTOGRAPHIC GENERALIZATION What is Generalization? • Generalization is the process of simplifying geographic features on a map while still maintaining their essential characteristics. This is important because it allows the map to be more readable and easier to understa...

Creating E ffective Maps CARTOGRAPHIC GENERALIZATION What is Generalization? • Generalization is the process of simplifying geographic features on a map while still maintaining their essential characteristics. This is important because it allows the map to be more readable and easier to understand. • Another definition: It is the process of modifying the distribution of some phenomena on the map, by modifying their structure and form, simplifying them to the maximum degree, and reducing their number and size. • Another definition: Generalization is a process of selection and generalization carried out on the content of geographical maps when they are drawn up, with the aim of preserving the general typical features and special characteristics of the features depicted on the maps in accordance with the map’s purpose, subject matter and scale capabilities. 2 Factors that affect the generalization process? 1. The goal or purpose of the map. 2. Preserving the original map information, as loss of information due to generalization may negatively affect the map user. 3. Preserving the contents of the original map in terms of geometric and geographical accuracy and primary characteristics. 4. Preserving salient and important features in the original map during the generalization process. 5. Choose an appropriate drawing scale for the reduction process, as there is a direct relationship between reduction and generalization, meaning that the greater the reduction process, the greater the effect of generalization on the original data. 6. The nature of the phenomena represented on the map and their relative importance Drawing Scale Goals for generalization , Why and When ? When ? Goals for generalization , Why and When ? Why ? Goals for generalization , Why and When ? What is the Goals ? How to generalize? Deletion and Selection Simplification Displacement Classification Merging Exaggeration Symbolization Deletion and Selection • It means limiting yourself to showing the necessary features on the map, from the point of view of the map’s purpose, and removing other, less important features. • Example. All rivers whose length is less than a name on the map scale 1:100 are deleted Classification Classification is defined as dividing things into specific classes, groups, or ranks according to common standards or foundations related to these things. Classification in cartography is used to achieve three things: • Classifying the collected data and information in order to compose a new map. • In order to classify the geographical phenomena to be represented on the map. • In order to carry out the process of cartographic generalization. The features depicted on the map are classified into several categories. Simplification Simplification is the softening of the edges and serrations of the formal features of linear and spatial features, while preserving their main general characteristics and distinctive qualities. The process of simplification is carried out on maps by removing small aliases from the shapes of linear and spatial features, and keeping the large aliases, which preserve the general formal characteristics of the phenomenon and the general direction of its path or location. Merging Merge means the joining or unification of several small geographical phenomena, spread adjacent to each other. Displacement Displacement means the simple movement of symbols of some geographical phenomena on maps from their actual locations to another nearby place, with the aim of showing and clarifying several adjacent symbols, whether they are point, line, or cadastral. Example: moving the road and railway slightly from the coastline, and moving the road slightly from the riverbed. Exaggeration E xaggeration means increasing the size and area of some symbols, of high relative importance, enough to appear clearly on the map. This process is done to meet specific needs of the map. E xample: He exaggerates the size of the symbols of touristically, religiously, or historically important cities to appear on the map, exaggerates the thickness of some lines representing main roads, and also exaggerates the thickness of the lines representing international borders. Symbolization Symbolization is based on replacing all the content of the map with point, line, and cadastral symbols that represent the features and phenomena spread in the geographical area represented on the map. When the Symbolization process is carried out on the map, the symbols are carefully selected to represent the geographical phenomena on a map according to its scale. Thank Y ou Have a Great Day