# Ordinance Survey Maps.

## Presentation on theme: "Ordinance Survey Maps."— Presentation transcript:

Ordinance Survey Maps

What we know so far: You should be able to understand and describe why and how maps are drawn to a particular scale. You should be able to identify a 4 figure grid reference on an ordinance survey map You should be able to identify a 6 figure grid reference on an ordinance survey map

Learning Outcomes: You will be able to measure the distance of a straight line and a curved line on a map. You will be able to measure the area of a feature on a map. You will be able to identify areas of different heights above sea level on a map You will be able to identify the different patterns of settlement on a map

Measuring Distance on a Map
Once we know the scale, it is easy to measure distances on the map. To measure a straight-line distance follow these 3 steps. 1. Place a strip of paper so that its edge passes through the 2 points. 2. Mark the edge of the paper where it passes each of the points. 3. Place the paper against the map’s linear scale and read the distance in km.

Measuring Distance on a Map

Measuring Curved Distances, e.g. a Road
Place the edge of your paper strip at the starting point you want to measure. Hold the edge of the paper along the edge of the road until you reach the first turn. Put a mark on both map and paper. Keeping both marks in line, move your strip until it is in line with the next section of the road. Put a mark where the road begins to turn. Continue this process until you have measured the complete distance. Place the paper strip on the Linear Scale and read the distance in kilometres.

Measuring Curved Distances, e.g. a Road

Calculating the area of your Map
To calculate the total area of your map follow these steps. Count the number of squares along the bottom of your map. Count the number of squares up along the side of your map. Multiply the two numbers that you get. Your answer will be in kilometres squared.

Calculating the area of your Map
Number of squares along the bottom = 4 Number of squares up along the side = 5.5 4 x 5.5 = 22 Area = 22km sq

Calculating the area of odd shapes
To calculate the area of an odd shape such as a lake complete the following steps. Count all of the full squares covered by the lake. Count all of the squares where the lake covers more than half of the square. Ignore those squares where the lake covers less than half of the square. Add your numbers from step 1 and 2 above to find your answer in km squared.

Calculating the area of odd shapes
Number of full squares = 3. Number of squares more than half full = 6 Ignore the others. Add your 2 numbers. 6 + 3 = 9km sq

Showing Height on a Map On all of the maps we use in class the height is shown in metres above sea level. For example, 200 would mean a place is 200 metres above sea level. There are 4 ways that height is shown on a map. Colour – Green less than 200m, Brown more than 200m. Contour Lines – Lines with the height written on it. Triangulation Station – Small triangle with height written beside it. Spot Heights – Small Black Spot with height written beside it.

Showing Height on a Map

The Steepness of a Slope

Settlement Settlement means where people are living.
People can live in cities, towns, villages, or in a one off house in the countryside. On the maps we use houses are shown as really small black squares.

Types of Settlement Linear Settlement – The houses are in a line along a road.

Types of Settlement Nucleated Settlement – The houses are in a small bunch or group.

Types of Settlement Dispersed Settlement – When the houses are scattered and there is no real pattern.

Antiquities – Ancient Settlement

Different Types of Symbols

Different Types of Symbols