[symbology] On a topographic map, concentric contour lines drawn with hachures to indicate a closed depression or basin . Concentric contour lines drawn without hachure marks indicate a hill.
What do contour lines represent?
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.
Do Hachure lines represent a depression or basin?
Hachured contour lines on a topographic map represent closed depression or basin .
Are present on a contour line it indicates a depression?
Depression – A contour line with tick marks inside it indicates a depression, rather than a peak. You should also see elevations decreasing as you get near the depression.
What is hachure line?
Hachures are short lines laid down in a pattern to indicate direction of slope . When it became feasible to map rough terrain in more detail, hachuring developed into an artistic speciality....
What are the 3 types of contour lines?
Contour lines are of three different kinds. They are the Index lines, Intermediate lines and the Supplementary lines .
Do all topographic maps use the same contour interval?
Different maps use different intervals , depending on the topography. If, for example, the general terrain is quite elevated, the map might run at 80- to even 100-foot (24- to 30-meter) intervals. This makes it easier to read the map — too many contour lines would be difficult to work with.
What depression lines indicate?
The closer together the inclines, the steeper the hill. On the other hand, the farther apart lines tend to indicate a depression in the landscape. Another way to tell elevation is the numbers on the map. Each number represents a different elevation, the higher the number, the higher the elevation (duh) and vice versa.
Why do contour lines never cross?
Contour lines never cross on a topographic map because each line represents the same elevation level of the land .
What does a depression look like on a topographic map?
Contour lines that show a depression, crater, or sinkhole on a map are represented by dashed lines (hachure marks) on the inside of a contour line . The elevation of the first depression contour is the same as the nearest regular contour line.
What is V rule?
The V-rule is one of the most important ways of determining quickly the dip of planar features , i.e. the map pattern of a planar surface (e.g. fault or bedding) ‘V’s in the direction that it dips. This paper model shows a valley that is perpendicular to the strike of a faulted sequence and a fault.
How do Hachure lines work?
Hachures are strokes (short line segments or curves) drawn in the direction of the steepest slope (the aspect direction). Steeper slopes are represented by thicker, shorter strokes, while gentler slopes are represented by thinner, longer and farther apart strokes.
How do you read Hachure lines?
Hachures are strokes (short line segments or curves) drawn in the direction of the steepest slope (the aspect direction). Steeper slopes are represented by thicker, shorter strokes, while gentler slopes are represented by thinner, longer and farther apart strokes.
What are the 5 Rules of contour lines?
Rule 1 – every point of a contour line has the same elevation. Rule 2 – contour lines separate uphill from downhill. Rule 3 – contour lines do not touch or cross each other except at a cliff. Rule 4 – every 5th contour line is darker in color .
What is the space between contour lines called?
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.
Does Google Earth show contour lines?
This KML network link displays a map overlay for USGS Contours (http://viewer.nationalmap.gov/) in Google Earth. To get started, simply download usgs-contours-overlay-for-google-earth. Or checkout all 4 USGS The National Map map overlays on this site. ...
