Map: Grid & Area References (Cartography)

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Presentation Description

How to locate an area/feature on a topographic map, with the help of Eastings & Northings.

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Presentation Transcript

Grid & Area References:

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:

Topographic maps are large scale and we use these for Area and Grid references

So how do we locate features on a Topographic map?:

So how do we locate features on a Topographic map? 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.

PowerPoint Presentation:

Eastings Northings N 18 17 16 15 22 23 24 25 26 27

Area Reference:

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 EXAMPLE: AR3363 easting northing

PowerPoint Presentation:

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: AR2215 The boy: AR2316

Grid References:

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

PowerPoint Presentation:

Eastings Northing 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

Interactives:

Interactives http://mapzone.ordnancesurvey.co.uk/mapzone/PagesHomeworkHelp/maptivity/gridreferences/ http://geographyfieldwork.com/TestGridIntro.htm

PowerPoint Presentation:

CLASS EXERCISE Give the (AR) for the following features: Church; Village Hall; Grove farm; The dairy farm; The town of Little Plumpton; The entire (AR) ’ s for Gibbet Wood; The (AR) ’ s that Dale Road passes through; The approximate (GR) of Grove farm.

PowerPoint Presentation:

http://www.mape.org.uk/startower/maps/resources/map1.htm http://www.mape.org.uk/startower/maps/resources/map1b.htm

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