Contour lines and landscapes (Science)
How to determine gradient
-dividing the relief (rise or fall) between two points on the map by the distance (run) between them (expressed as a fraction in feet per miles or meters per kilometer)
Gradient
-measure of the steepness of a slope
Regional relief
-total relief -difference in elevation between the highest and lowest points on a topographic map
A map with a contour interval of 20m has drawn at
0m,20m,40m,and so on
General characteristics of topographic maps
1. contour lines do not cross each other, divide, or split 2. closely spaced contour lines represent steep slopes, conversely contour lines that are spaced far apart represent gentle slopes 3. Contour lines trend up valleys form a V or a U where they cross a stream
Contour intervals of a map is usually given
In or near the maps legend
Elevation
Is the height of an object above the surface of the sea
Sea Level is
Sea level is 0 meters. Sea level is niether positive nor negative
What is the contour interval based on
The relief in the area
What types of relief and contour intervals do plains have
They have low relief and usually small contour intervals
True or False: Isolines are always closed lines
True
Contour lines that cross a valley or stream are
V-Shaped
Each contour line represents
a certain elevation
Contour lines that are far apart show
a gentle slope
Contour lines that are close together show
a steep slope
Why do contour lines at different heights not cross each other?
all points on a single contour line are at the same height
water on a top map
blue
Isolines
connects points of equal value
Contour lines never
cross
All points on a contour line stop at the same
elevation
Each contour line shows a different
elevation
Contour lines are used to show
elevation of a topographic map are lines that connect
Vegetation on a topo map
green
What types of relief and contour intervals do mountains have?
high relief and large contour intervals
Depression Ring
inner ring indicates a depression (lowest elevation) which the map will show with a series of small tick marks pointing towards the center -closed loops without hachures are always uphill on the inside and downhill on the outside --> this means hills and mountains will appear on the map as a cluster of concentric O shapes
Isolines are drawn at
regular intervals -i.e. every 5 degrees of temperature difference
Depressions are marked with
short, straight lines inside the circle
A topographic map is a map that shows (4 things)
surface features of an area,natural features,man-made features,and elevation
Slope
the amount of rise or fall of a surface
The direction the V points toward determines
the area of higher elevation or upstream
The depression lines point toward
the center of depressions
The diffrence between any 2 countour lines is called
the contour interval
Relief
the difference in elevation between land forms, specific points, or other features on a landscape or map
Contour interval
the elevation between any two adjacent contour lines of different elevation on a topographic map - often every 5th contour line is heavier so that you can count by 5 times the contour interval
The space between contour line depends on
the slope of the ground
What do close closed circles represent
the top of hills, mountains, and depresions
When isolines are far apart -
they show a gradual horizontal change
When isolines are close together -
they show a rapid horizontal change
Index lines
thickest contour lines, usually labeled with a number at one point along the line -tells you elevation above sea level
The apex of the V always points
upstream
Isoline trends
value difference between any 2 consecutive isolines