
5f79e09065577fe77de7cbfeff861eb6.ppt
- Количество слайдов: 19
Grid & Area References • It can be difficult to find places or features easily on a map. •
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.
18 17 16 N 15 Northings 22 23 24 Eastings 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: AR 3363 easting northing
The Area Reference of the house is: 18 AR 2317 Remember with (AR) you use the bottom left hand corner 17 What is the (AR) for: The plane: AR 2215 16 The boy: N AR 2316 15 Northings 22 23 24 Eastings 25 26 27
Area references 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. 39 10 38 8 7 6 5 A 9 4 3 2 1 37 36 35 21 22 23 24 25 26 CLICK to CLICK for start. . . the next square A
Area references 39 10 38 8 7 6 5 A 9 4 3 2 1 B 37 B 36 35 21 22 23 24 25 26 CLICK for the next square
Area references 39 10 38 8 7 6 5 A 9 4 3 2 1 C 37 B 36 C 35 21 22 23 24 25 26 CLICK for the next square
Area references 39 10 38 8 7 6 5 A 9 4 3 2 1 D D 37 B 36 C 35 21 22 23 24 25 26 CLICK for the next square
Area references A = 2238 B = 2536 39 A C = 2235 38 D = 2337 D 37 B 36 C 35 21 22 23 24 25 26 CLICK get How did you. TO on? CHECK EACH ANSWER
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. Dividing the easting and northing into tenths Example: GR 335638 easting northing
What is the grid reference (GR) for the ball in which the boy is about to catch? 18 17 Answer: GR 238169 16 N 15 22 Northing 23 24 Eastings 25 26 27
Come up to the Interactive White Board
Compass Directions 68 F H I B 66 21 22 E NW D A 67 J N C NE W G 23 E SE SW S 24 What direction are you walking ? A C G D F H I J B E A
Interactives • http: //mapzone. ordnancesurvey. co. uk/map zone/Pages. Homework. Help/maptivity/gridr eferences/ • http: //geographyfieldwork. com/Test. Grid. Intr o. 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/re sources/map 1. htm • http: //www. mape. org. uk/startower/maps/re sources/map 1 b. htm
5f79e09065577fe77de7cbfeff861eb6.ppt