Mapwork Flashcards
What are two different types of maps
Political Population density and distribution Physical Transport Topographic Orthophoto
What are SAs provinces
Western,northern, eastern cape North west Free state Limpopo Gauteng Mpumalanga Kwazulu-natal
What is direction
Description of how one place lies in relation to another
From is the?
Starting point
To is the?
Ending point
When determining flow of river:
Flow from high to low altitude
Flow away from dam walls
Contour v points upstream therefore river flows in opposite direction to contour v
Angle at which the tributaries join the main stream will indicate direction of flow
What is true bearing
Measurement of how one place lies in relation with another
How do you measure true bearing
Single reference point used. Eg true north
What is the basic method of calculation
1) draw straight like joining two reference points
2) place protractor with origin on starting point and 0 aligned with TN
3) measure CLOCKWISE then read answers. Must be stated in degrees
What is Alpha-Numeric
Simplest form of grid reference
Letters and numbers used to describe block subject is in
What are co ordinates
They are far more accurate in measuring exact location
What needs to be understood in order to determine co ordinates?
Lines of latitude and longitude
Degrees
Minutes
Seconds
What are lines of longitude
Lines that join north and south poles (-3.2)
What are lines of latitude
Parallel line, move equidistant N and S of equator (-3,6)
Degrees?
Indicated in both map reference numbers and on top left corner
Minutes?
Indicted by scales down the side and across top of map (each side is 1min)
Seconds?
Not indicated on map therefore must be calculated
Latitude readings are
Always SOUTH
Longitude reading are
Always EAST
What type of map is used for map referencing number
Topographical
What is map referencing number
Topographical maps given a map reference/map ordering number
Eg 2229DD
What does a map scale refer to
Ratio between a distance on a map and the corresponding distance on earth
How is map scale determined
By how much detail is required on a map
What are the types of map scale
1) ratio
2) line
3) words e.g one centimeter on map represents five hundred meters on land
What does the scale of 1:100 000 mean
(1cm on map= 100 000 cm on land
100 000 cm = 1km)
THEREFORE 1cm=1km
What is the ratio scale for topographical maps
1:50 000 : 1cm=1km
What is the ratio scale for orthophoto maps
1: 10 000 : 1cm = 1/2km
When using topographic scale, how much do measured distances need to be divided by
2 (or x by 1/2)
What is a map?
Scaled down version of real world
What does 1: 10 000 divided by to convert cm into km and what type of map is it
Orthophoto
Divided by ten or multiplied by 1/10
How much smaller is a topographical map than a orthophoto
5x smaller
What are the two maps used in straight line distances
Topographical and orthophoto
How do you get km in a topographical map
Measures actual distance between two points on the map then divide by two = distance in km
How do you get distance in km in orthophoto map
Measure distance between two points and divide by ten
When is curved line distance used for
Measuring distance
What is the formula for area
A= lxb
Find area for topographical map
Convert length and breadth cm readings into km by dividing each by two
Find area for orthophoto map
Convert length and breadth reading into km by dividing by 2
When finding area, what is the final answer measured in
Km squared
How do you calculate in hectares
Area in km squared x 100
When substituting values of formula into t= d/s what happens
Km cancel out and multiply answer by 60
What is a contour and relief
Line of map that joins all places of equal height above sea level
What is a contour
Line on a map that joins all places of equal height above sea level
What are contour intervals on the topo map
20m
What are the contours on the ortho map
Drawn at 5m intervals with 20 m intervals highlighted as dark lines
What are contours used for
To show relief of a region
What do the patterns created by the lines indicate
What type of features are found in the landscape
The nature of the slope
How do we know the slope is steep with contour
The lines are closer together
What does it mean if the contour lines are far apart
The slope is more gradual/gentle
