area and grid references
TRANSCRIPT
1Geography Skills and Tools
Area and Grid Reference
Mr Shipp
Grid & Area References• It can be difficult to find places or features easily on a map.
• So far we have learnt that to find places on a street directory we use an alpha-numeric grid (e.g. B7)
• We also know that to find places on a larger scale, such as a world map we use Latitude & Longitude coordinates to help us find what we are looking for.
Topographic maps are large scale and we use these for Area and Grid references
So how do we locate features on a Topographic map?
• http://news.bbc.co.uk/2/hi/uk_news/wales/north_west/7824895.stm
• This BBC link details the importance of Grid References for emergency services to reach rural areas.
• We can locate places easily on a topographic map by using the maps gridlines.
• On a topographic map the vertical ( )lines are called eastings because they increase in value as we move eastward.
• The horizontal ( ) lines are called northings because they increase in value as we move northwards.
Eastings
Northings
N
18
17
16
15
22 23 24 25 26 27
Area Reference• Features such as a small lake, quarry or village are
usually located by means of an Area Reference (AR)
• To find the (AR) of a feature we use the coordinate in the lower left-hand corner of the grid square in which the feature is located.
• You always read the easting first then the northing. (hint to remember E comes before N in the alphabet)
• An area reference always has 4 figures • Into the house and up the stairs” may help you
remember!!
EXAMPLE: AR3363
easting northing
Eastings
Northings
N
18
17
16
15
22 23 24 25 26 27
The Area Reference of the house is: AR2317 Remember with (AR) you use the bottom left hand corner
What is the (AR) for:
The plane:AR2215The boy:AR2316
Area references
21 22 23 24 25 26
39
38
35
36
37
A
Time now for a little test. FOUR squares are going to be highlighted and you have TEN seconds to write down the area reference for each square.
10 9 8 7 6
5 4 3 2 1
ACLICK to start.....
CLICK for the next square
Area references
21 22 23 24 25 26
39
38
35
36
37
A10 9 8 7 6
5 4 3 2 1
BCLICK for the next square
B
Area references
21 22 23 24 25 26
39
38
35
36
37
A10 9 8 7 6
5 4 3 2 1
CCLICK for the next square
C
B
Area references
21 22 23 24 25 26
39
38
35
36
37
A10 9 8 7 6
5 4 3 2 1
DCLICK for the next square
C
B
D
Area references
21 22 23 24 25 26
39
38
35
36
37
A
CLICK TO CHECK EACH ANSWER
C
B
D
A = 2238
B = 2536
C = 2235
D = 2337
How did you get on?
Grid References• We can locate relatively small and more specific features
on map by using Grid Reference (GR). • (GR) locates the exact point on the grid. • Unlike (AR), Grid Reference uses 6 figures. -The first two numbers of each coordinate refers to the eastings and
northings that surround the map. - The third number needed to complete each coordinate is obtained by
dividing each easting and northing into tenths.
Example: GR335638
easting northing
Dividing the easting and northing into tenths
EastingsNorthing
N
18
17
16
15
22 23 24 25 26 27
What is the grid reference (GR) for the ball in which the boy is about to catch?
Answer:
GR238169
6-figure grid referencesCome up to the Interactive White Board
Compass Directions
21 22 23 2466
67
68 F
A
BGC
H
E
I DJ
N
E
S
W
NW NE
SESW
What direction are you walking ?D F H I JGA C EB A
Interactives
• http://mapzone.ordnancesurvey.co.uk/mapzone/PagesHomeworkHelp/maptivity/gridreferences/
• http://geographyfieldwork.com/TestGridIntro.htm
CLASS EXERCISE
Give the (AR) for the following features:
1. Church;
2. Village Hall;
3. Grove farm;
4. The dairy farm;
5. The town of Little Plumpton;
6. The entire (AR)’s for Gibbet Wood;
7. The (AR)’s that Dale Road passes through;
8. The approximate (GR) of Grove farm.
Interactives
• http://www.mape.org.uk/startower/maps/resources/map1.htm
• http://www.mape.org.uk/startower/maps/resources/map1b.htm