more on maps
DESCRIPTION
surveyingTRANSCRIPT
CE 221 – Higher Surveying
Elements of a mapElements of a map
3More on Maps; Prepared by Andre‐Paul C. Ampong
Elements of a mapElements of a map
4More on Maps; Prepared by Andre‐Paul C. Ampong
Elements of a mapElements of a map
5More on Maps; Prepared by Andre‐Paul C. Ampong
Elements of a mapElements of a map
6More on Maps; Prepared by Andre‐Paul C. Ampong
Elements of a mapElements of a map
• Map titleMap title• North arrow
l• Bar scale
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Map titleMap title
• The map title tells of the content and theThe map title tells of the content and the purpose of the map
• It should be brief but concise• It should be brief but concise
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North arrowNorth arrow
• The north arrow points to the northernThe north arrow points to the northern direction thereby orienting the map to the real world
• It should be simple in design• North arrow should be of sufficient length toNorth arrow should be of sufficient length to permit the accurate scaling of directions on any part of the map
• The arrow may be drawn boldly but must not be so conspicuous
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Map scaleMap scale
• The map scale determines the size of the mapThe map scale determines the size of the map compared to the actual size of the area in the real world it representsreal world it represents
• It relates how unit measurements in the map compare to actual dimensionscompare to actual dimensions
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Map scaleMap scale
• Equivalence scaleEquivalence scale– 1 inch = 1 mile1 centimeter = 1 kilometer– 1 centimeter = 1 kilometer
• Scale ratio or representative fraction/– 1/5000 or 1:5000
– 1:100
• Graphic scale
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Map scaleMap scale
MDSR =GD
SR =
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ProblemsProblems
1 Determine the scale of a planimetric map1. Determine the scale of a planimetric map whereon 5cm represents 15,000m on the groundground.
2. The ground distance between two points is 25km If the distance between the same25km. If the distance between the same points on a topographic map is 50mm, determine the scale of the mapdetermine the scale of the map.
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ProblemsProblems
1. Compute the approximate area, in square1. Compute the approximate area, in square meters, of a rectangular shaped tract of land whose sides measure 29.67mm by 64.19mm on a map drawn to a scale of 1:25,000.
2. A graphic scale is to be designed for a topographic map with a given fractional scale of 1:75,000. Determine the length on the
hi l hi h ill 500graphic scale which will represent 500m on the map
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