Mapwork

Question 1

List 4 Characteristics of a Orthophoto map

Answer 1

1:10000
Black & white aerial photo
More detail
Contour interval 5m

Question 2

What is a map?

Answer 2

A reduced version of reality

Question 3

What are grid references?

Answer 3

Points of intersection between lines of latitude and longitude

Question 4

What is scale?

Answer 4

How many times reality has been reduced

Question 5

What map features does this Mapcode represent:

2930CB

Answer 5

29 degrees longitude(N or S)
30 degrees Latitude(E or W)
Big block C
Small block B

Question 6

How do you work out distance?

Answer 6

        100 000

Question 7

What is the formula for area and what are the steps to work it out?

Answer 7

Formula -> A = L x B

Steps:

1. Convert measurements to Km
2. Input values into the formula

Question 8

List 4 characteristics of a topographical map

Answer 8

1:50000
Colour
Physical features
Contour interval 20m

Question 9

List 3 ways scale is shown on a map

Answer 9

1. Ratio scale
2. Linear scale
3. Word scale

Question 10

How do you work out gradient?

Answer 10

G = H
—–
D

Gradient = Difference in height/Distance between the points

Steps:

1. Work out D, measure and convert distance to Kilometers
2. Convert the kilometers into meters by multiplying by 1000
3. Work out H by working out the difference in heights between the 2 points.
4. Then fill in the equation and divide both the H & D by the H, to get a 1:something ratio

Question 11

How do you work out true bearing?

Answer 11

Steps:

1. Draw a North to South line, making sure the object is in the centre
2. Then draw a line from the inject to the other object
3. Measure the angle with a protractor

Question 12

How do you work out Magnetic bearing?

Answer 12

MB = True bearing + Magnetic declination

Steps:

First workout True bearing

1. Draw a North to South line, making sure the object is in the centre
2. Then draw a line from the inject to the other object
3. Measure the angle with a protractor

Then add the MD, remember that it cannot be more than 360 degrees(Start from 0 again)

Question 13

What is Altitude?

Answer 13

The height above sea level

Question 14

List 4 ways altitude is shown

Answer 14

1. Contour lines
2. Spot heights
3. Trig beacons
4. Benchmarks(roads only)

Question 15

What do contour lines far apart represent?

Answer 15

A gentle slope

Question 16

What do contour lines close together represent?

Answer 16

A steep slope

Question 17

What do contour lines that touch represent?

Answer 17

A cliff

Question 18

What do almost circular contour lines represent?

Answer 18

A hill

Question 19

List characteristics of a Ridge/Spur’s contour lines

Answer 19

1. Higher altitude contours on inside
2. “V” shaped
3. Contours always point downstream
4. River flows in direction to contours

Question 20

List characteristics of a Valley’s contour lines

Answer 20

1. Higher altitude contours on inside
2. “V” shaped
3. Contours always point downstream
4. River flows in direction to contours

Question 21

List characteristics of a Concave slope’s contour lines

Answer 21

Close together then far apart

Question 22

List characteristics of a Convex slope’s contour lines

Answer 22

Far apart then close together

Question 23

List 4 types of aerial photographs

Answer 23

1. Horizontal(Parallel to ground)
2. High oblique(angle 60 degrees from vertical- horizon visible)
3. Low oblique(angle 30 degrees from vertical- no horizon)
4. Vertical(Straight above)

Question 24

List 2 advantages that both horizontal and oblique aerial photos have

Answer 24

1. Show depth

2. Can recognize objects

Question 25

List 3 disadvantages that both horizontal and oblique aerial photos have

Answer 25

1. Size is distorted 2. Objects near camera obstruct the view of objects behind 3. Objects near camera appear bigger than objects behind

Question 26

List 2 Advantages and 1 disadvantage of a Vertical aerial photo

Answer 26

``` Advantages: 1. Scale is the same, good for working out area 2. No objects obstructed by others Disadvantage: 1. Objects hard to recognize ```

Question 27

What is a cross section?

Answer 27

A side view of a relief feature

Question 28

What is GIS?

Answer 28

A system for manipulating, analyzing, capturing, checking, storing and displaying data which are spatially referenced to the earth

Question 29

What does GIS stand for?

Answer 29

Geographic Information System

Question 30

What does GIS do?

Answer 30

It links different layers to make a digital map

Question 31

How do humans collect data for GIS?

Answer 31

Remote sensing - collects data of the earth's surface through orbiting satellites and aircraft

Question 32

What 3 types of data does GIS have?

Answer 32

Point - no length or area(Spot heights) Line- Length but no area(Roads) -NODES ARE THE START AND END POINTS Area- Length and Area, polygon(️Farm, Park)

Question 33

What is passive remote sensing?

Answer 33

It is the collection of data using sensors that measure natural radiation from the earth

Question 34

What are the limitations of passive remote sensing?

Answer 34

Natural radiation does not penetrate clouds, smoke or rain

Question 35

What types of information can both Passive and Active remote sensing get about the earth?

Answer 35

Temperature, soil type, land use ect.

Question 36

What is Active remote sensing?

Answer 36

Satellite systems send out their own radiation towards the land, sensors then measure radiation which is sent back from Earth.

Question 37

Are there any limitations to Active remote sensing?

Answer 37

No, it can get data at anytime, and can penetrate clouds, rain and smoke.