Elevation contours are imaginary lines connecting points having the same elevation on the surface of the land above or below a reference surface, which is usually mean sea level Contours make it possible to show the height and shape of mountains, the depths of the ocean bottom, and the steepness of slopes
What do contour lines indicate?
A contour line is a line drawn on a topographic map to indicate ground elevation or depression A contour interval is the vertical distance or difference in elevation between contour lines Index contours are bold or thicker lines that appear at every fifth contour line
For what purpose is contour lines used on a map?
Contour lines are lines drawn on a map with equal elevation points, so elevation would be constant if you followed the contour line physically The elevation and terrain shape of the contour lines shows It is useful because they show the form of the land surface on the map–its topography
What do contour lines on a topographic map show quizlet?
Contour lines are used to show elevation on a topographic map Lines or isolines on a map that connect points with the same elevationContour lines rules: Contour lines never cross All points on a contour line are at the same elevation The space between contour lines depends
How do contour lines indicate streamflow on a topographic map?
All rivers flow downhill from higher to the lower elevations, perpendicular to the contour line above it As a rule of thumb, the V-shaped contour is pointing upstream (the opposite direction from the flow of a stream or river) The “V” shape contours indicate streams and drainage
What are contour lines quizlet?
Contour line a line on a map joining points of equal height above or below sea level
What is a contour interval on a topographic map?
Individual contour lines on a topographical map are a fixed interval of elevation apart known as a contour interval Common contour intervals are 5, 10, 20, 40, 80, or 100 feet The actual contour interval of a map depends upon the topography being represented as well as the scale of the map
What do closely spaced contour lines indicate?
Closely spaced contour lines indicate steep slopes Widely spaced contour lines indicate gentle slopes or relatively flat areas A contour line that forms a closed loop with no other contour lines inside indicates a hilltop Contour lines form “V” shapes in streams
What do the contour lines do as they cross over a stream?
When contour lines cross a stream, they form a “V” that always points uphill As a general rule, water flows downhill perpendicular to contour lines
How must contour lines bend on a topographic map to indicate a stream valley?
A contour line that bends to form a V shape indicates a valley The bend in the V points toward the higher end of the valley; this V points upstream, or in the direction from which the water flows, if there is a stream
How do you identify contour lines on a map?
Ever noticed those squiggly lines all over your hiking map? Other than the obvious trails and rivers, these squiggly lines are contour lines Put simply, contour lines mark points of equal elevation on a map If you trace the length of a line with your finger, each point you touch is the same height above sea level
How do you read elevation contour lines?
You can figure out the elevation of any point by finding the nearest labeled line, counting the number of lines above or below it, multiplying by the contour interval, and adding or subtracting the result from the nearest marked contour line The more closely spaced the contour lines, the steeper the slope
How do you count contour lines on a map?
Maps generally count five contour lines from one index line to the next, including the next index line As with counting from one number to the next, like from five to 10, Start with the next line of the index line, Counting each contour line up to and including the next index line
What is a contour interval on a topographic map quizlet?
The change in elevation from contour line to contour line is called the contour interval such as 1,600 or 2,000 feet
When contour lines form closed circles This represents a?
2 Concentric circles indicate a hill When contour lines form closed loops all together in the same area, this is a hill
What does a topographic profile show?
Topographic maps are a detailed record of a land area, giving geographic positions and elevations for both natural and man-made features They show the shape of the land the mountains, valleys, and plains by means of brown contour lines (lines of equal elevation above sea level)
What is the space between contour lines called?
The elevation difference between two adjacent contour lines is called the contour interval (CI) Usually the contour interval is noted on the map legend In most topographic maps every 5th contour line is drawn in bold print or wider than other contours
What do closely spaced contour lines indicate about the ground surface represented on a topographic map quizlet?
What do closely spaced contour lines indicate? They indicate a steep slope
What do closely spaced contour lines on a topographic map indicate about the shape of a feature?
Closely spaced contour lines indicate a steep slope (Figure F-1) 2 Widely spaced contour lines indicate a gentle slope (Figure F-2)
What do concentric contour lines indicate?
Concentric circles of contour lines indicate a hilltop; concentric circles with hachure marks indicate a close depression (Figure 76)
Why do contour lines never cross on a topographic map?
Contour lines never cross They may come very close to each other (eg along a cliff), but by definition they may never cross each other * This is because one location on the surface of Earth cannot be at two different elevations!
Why do contour lines always point upstream?
Contour lines “point” upstream when they cross a river or stream The arrow below points to the direction the water flows, which is always downhill If you need help remembering, think of it this way: the contours at a stream or river are in a “V” or “U” shape
When reading a topographic map describe the contour lines when the slope of a land is gradual?
Contour intervals reveal how much vertical distance there is between each contour line—closely spaced contour lines indicate very steep slopes Contour lines that are sharply tapered indicate an uphill direction Rounded contour lines typically indicate a downhill direction (gradual slope)
Do satellite maps include contour lines that show relief?
Satellite maps include contour lines that show relief No, contour lines represent one specific elevation and connects points of EQUAL elevation
What happens to contour lines when there is a vertical cliff or wall?
Contour lines can merge to form a single contour line only where there is a vertical cliff for wall Evenly spaced contour lines of different elevations represent a uniform space The closer the contour lines are to each other the steeper the slope In other words, the steeper the slope the closer then contour lines