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Published byHerman Hardja Modified over 6 years ago
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Isolines An isoline is a line connecting points of equal value.
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Examples of isolines: (The weather channel loves isolines!) Isotherms:
points of equal temperature Isobar: points of equal barometric (air) pressure Contour: points of equal altitude or elevation Anything else you can get a value for. (The weather channel loves isolines!)
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Rules for Drawing Isolines:
1. Isolines connect points of equal value. 5 5 10 10 10 10 15 15
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2. Isolines are gentle, curving lines- no sharp corners.
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3. Isolines are always closed curves even though the map might only show part of it.
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4. Isolines NEVER cross- this would mean that one point has two different values. Ex: one spot has two temperatures? 60 ° 50 ° 40 ° 30 ° X 20° Z Y
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5. Isolines usually are parallel. (They have a parallel trend.)
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Isoline and Contour Line Rules
Contour line must never split or divide Contour lines must never simply end except at the edge of a map Contour lines represent one and only one elevation Contour lines may never intersect other contour lines. Overhanging cliffs are the exception
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Rules continued Contour lines form a V-pattern crossing streams.
V will always point upstream Contour lines close together represent a steep slope or gradient, widely spaced lines indicate a gentle slop. Concentric circles of contour lines indicate a hill top or mountain peak Concentric circles of hachured contour lines indicate a closed depression
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Visualizations of contour lines
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Gradient Gradient shows how quickly the value changes from one point to another.
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A gentle (low) gradient changes slowly and the lines are far apart.
A steep (high) gradient changes quickly and the isolines are close together. A gentle (low) gradient changes slowly and the lines are far apart. Steep area Gentle area
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Making Contours worksheets
Worksheets can be printed from:
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Highlight data points.
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Fill in gaps in data.
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Connect the dots.
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Go on to the next value.
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Making a Contour Map II
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Drawing Contour Maps III
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