Maps and map reading -Contours
Any ordnance survey map represents the real world as a flat sheet. To give us an idea of hills, valleys and other three dimensional objects the map is covered in contours normally thin brown lines that connect areas of equal height on the map. Staying between the same contour values does not mean that the land is flat it just means that it falls between the two contour values. Typically up to 10m variation which is quite a bit of variation. Crossing contours you either move up or down in altitude. The spacing between the contours gives you an idea of how steep the ground is too.

Close contours show steep ground as you can see on one of the hills that our scouts climbed in 2009.

Wide spaced contours show gentle slopes like these round Burwash where we held the Kings of the wild frontier camp in 2008

Roll over the images to see the photo of the area and click for a larger map

How steep are the contours?
You have to be careful when looking at the map since the steepness also depends upon the interval between the contours. On the Welsh map the steps between the contours are every 10m whereas the contours on the Burwash map are every 5m. You can make a 3d model of the map area by tracing the ndividual contours onto pieces of cardboard line by line then sticking them on each other. It is easy to get an idea of the map and how it really looks on the ground.

To get an instant idea of steepness draw a line with your scale or compass between two contour points making sure that you measure at right angles. Then taking a piece of paper draw a graph of the distance along the line and plot against the change in height.

For the Welsh and Burwash maps typical plots look like this so you can see the difference in steepness.

Working out grid references
Walking to time