Rules of Contour Lines Every point on a contour line is of the exact same elevation By definition, contour lines separate points of higher elevation from points of lower elevation Contour lines never cross Contour lines never split
What are the 5 rules for 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 are the 8 rules of contouring?
General Rules for Contour Lines 1 Contour lines connect points of equal elevation; therefore every point along a contour line is the exact same elevation 3 Contour lines never split or divide 4 Contour lines always separate points of higher elevation (uphill) from lower elevation (downhill) 5
What 3 things do contour lines show?
Contour lines are lines drawn on a map connecting points of equal elevation, meaning if you physically followed a contour line, elevation would remain constant Contour lines show elevation and the shape of the terrain They’re useful because they illustrate the shape of the land surface — its topography — on the map
What are the six rules for reading a topographic map?
Terms in this set (6) Rule 1: Slope The closer the lines are, the steeper the slope Rule 2: Flow and Source of a River/Stream Rule 3: Mountains and Hills Rule 4: Highest possible elevation of a hill/mountain Rule 5: Depressions Rule 6: Lowest possible elevation of a depression
What are the rules for topographic maps?
Rules of Topographic Maps Contour lines always separate points of higher elevation (uphill) from lower elevation (downhill) Contour lines never cross or intersect Contour lines never split or divide Contour lines always close to form a shape, usually an irregular circle
What are 4 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
Can a contour line split?
Contour lines never split or branch
What are the properties of contour lines?
Characteristics of Contours Must close on themselves, on or off the map Perpendicular to the direction of max Slope between them is assumed uniform The distance between them indicates the steepness of the slope, gentle or steep Irregular signify rough, smooth signify gradual slopes
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 are the 3 factors that should be considered upon planning and designing of a contour interval to be used for a topographic map?
Contour interval on a map is decided on the following considerations: 1) Scale of the map The contour interval is kept inversely proportional to the scale of the map 2) Purpose of the map 3) Nature of the ground 4) Availability of time and funds
What is a contour plan?
Contour plans are a graphical representation of the lay of the land They can be used to determine the extent of cut and fill needed, the height of retaining walls, and the overall finished height of buildings referenced back to natural ground level
How do you read 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 If you were to walk the path of a contour line in real life, you would remain at the same elevation the whole hike, never traveling up or down
What is a contour line in drawing?
A contour line defines the outline of a form, as well as interior structure, without the use of shading A fundamental basis of drawing, contour lines are usually the first technique children adopt to draw people, houses, and trees
What are the 5 rules of a topographic map?
Topographic Map Rules Contour Lines Never Cross Measuring Steepness Stream Flow Direction Contours Close Concentric Circles Elevation Between Lines
What is the use of contour line?
The purpose of contour lines is to represent the tridimensional shape of the terrestrial surface on a bidimensional map Contour lines are the intersection of an horizontal plane parallel to the reference level and the topographical surface to describe
When can contour lines intersect?
Contour lines can never cross one another Each line represents a separate elevation, and you can’t have two different elevations at the same point
How do contours work?
Contour lines connect points that share the same elevation: Where they’re close together (they never intersect), elevation is changing rapidly in short distance and the terrain is steep Where contour lines are wide apart, elevation is changing slowly, indicating a gentle slope
How many feet of elevation are there between contour lines?
Contour lines are generally illustrated as a brown line 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
When a contour line crosses a river the line?
Rule # 4- Contour lines that cross a valley or stream are V-shaped Contour lines “point” upstream when they cross a river or stream Look at the Mill River in the map to the right The V points toward the area of higher elevation
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 is contour in civil engineering?
Contour • An imaginary line on the ground surface joining the points of equal elevation is known as contour • In other words, contour is a line in which the ground surface is intersected by a level surface obtained by joining points of equal elevation
What happens if you walk along a contour line?
If you walk along a contour line you will not go uphill or downhill Each line connects all points of a specific elevation Contour lines never cross since a single point can only have one elevation Every fifth contour line is bolded and labeled
What is the zero contour line?
contour interval The zero contour line is sea level the line that is shaded darker than the rest is the index contour
Why do contour lines never cross?
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!