Map Reading and Interpretation
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The document discusses map reading and interpretation. It covers relief representation using contour lines on maps, drainage patterns, and human-made features. Students will learn about contour lines, how they represent 3D relief on 2D maps, and how to draw contour lines and cross sections. Contour lines connect points of equal elevation and come in three types: index lines with elevation numbers every fifth line, intermediate lines between the index lines, and supplementary dashed lines for half-interval changes in elevation.
Map Reading and Interpretation
- 1. MAP READING AND INTERPRETATION Mr. Yonas Gemeda December 2019 Addis Ababa
- 2. Content Introduction Relief representation on contour map Drainage on map The study of human made features on map Geographical information systems (GIS) unit revision
- 3. Learning outcomes • At the end of this unit, students will be able to: Review the definition and properties of contour lines Realize how contour lines are used to represent relief features on maps and types of contour • Acquire the skills of drawing contour lines, cross sections.
- 4. Introduction Map What is map? • A map is a drawing or graphical representation of the land, as viewed from the air from a great height. This perspective is called the "aerial view" or "map view." As land bound creatures who usually walk across the land rather than fly above it, the map view is not the natural perspective for humans; rather, we have more of a "side view" of the land surface.
- 5. Elements of map • Dsgfjhk • cgfdht
- 6. Elements
- 8. Relief representation on contour map • Relief The term relief refers to the way that the earth’s surface arranged. The relief feature of the earth is 3D. These are: length Breadth And height
- 9. Cont’d • These three dimensional features are represented on two dimensional ,maps. • Traditionally reliefs of earth surface showed by: Hachuring Hill shading Layer tinting Form lines
- 10. Current • These days they are replaced by contour lines. • Contour lines • Contour lines are also known as isohypes. • They are imaginary lines which are drawn on maps connecting places having the same height above or below sea level.
- 11. Contour lines • The term contour line is most commonly used in cartography. However, the term isobath for underwater depths on bathymetric maps and isohypse for elevations are also used. • The process of drawing contours on a map is called isopletion.
- 12. Contour lines
- 13. Types of contour • Three are three types of contour lines shown on standard topographic maps. These are: I. Index : starting at a zero elevation or mean sea level, every fifth contour line is a heavier line. Each index contour line is numbered at some points. This number is the elevation of that line.
- 14. Cont’d II. Intermediate : the contour line falling between the index contour lines are called intermediate contour lines. These lines are finer and do not have elevation given. There are four intermediate contour lines between index contour lines.
- 15. Cont’d III. Supplementary: these contour lines resemble dashes. They show changes elevation of at least one half the contour interval.
- 16. Types