OS map symbols: reading the key and spotting features

A family is booking a holiday cottage from an advert that promises peaceful countryside, and the map beside it seems to disagree. Which would you trust? The cottage is near the village of Featherby, in the fictional land of Owlobia, and the map is drawn in the Ordnance Survey style. Within a kilometre of the cottage, the map shows three small symbols. Anyone can read them, once they know the key. The family are about to pay for peace and quiet, and the map has already told them what is next door. Once the key makes sense, those three symbols will read themselves.

The key is the panel printed with every OS map that says what each symbol stands for. A symbol is a small mark, line or patch of colour that stands for something real on the ground, such as a church or a footpath. The key sorts its symbols into groups of the same kind, so the water symbols sit together and the vegetation symbols sit together. Tourist information has its own group, usually printed in blue. You match a symbol to the key by two things at once, its shape and its colour, the way you might match a sock by its pattern and its shade. Now a quick one: what colour would you expect a campsite symbol to be? Blue, because a campsite counts as tourist information. The two exam scales show different amounts. A one to fifty thousand map covers a wider area with less detail. A one to twenty-five thousand map shows more, down to field boundaries and extra paths. Some symbols change between the two. A public right of way, a path anyone may legally walk, is printed red on a one to fifty thousand map and green on a one to twenty-five thousand map. That is why the key printed with the exam map is the one to use, every time. Woodland shows how exact the key is. It has one symbol for coniferous trees, the needle-leaved kind such as pines, and another for non-coniferous trees, the broad-leaved kind such as oaks. Take grid square four two one seven of a one to fifty thousand map. In the west half of the square, the two tree symbols appear together. Option A says the woodland in it is coniferous. Option B calls the woodland nothing more than trees. Option C calls the woodland a plantation of trees. Option D calls the woodland in it mixed wood. Which one names the woodland in square four two one seven? It's D, the key's own name for the two kinds growing together. Now a harder question: why is it D and not A? Coniferous names only half of what is in the square. The non-coniferous symbols are there too, and mixed wood is the key's word for both together. Trees is too vague to match any entry in the key. Plantation is not one of the key's woodland words at all. One examiner's report on a question like this spells out the right answer. "The woodland in the grid square included both coniferous and non-coniferous trees and this type of land use is labelled as 'mixed wood' on the OS map key." The fix is to lift the key's own words into your answer, word for word. If you found the square and read the key, a report on another year's woodland question says most students did too, though some wrote plantation, which was marked incorrect. The east half of square four two one seven has a lake. Beside the lake are a blue tent symbol and a blue letter P. What is one facility for visitors in that square? A campsite, or a car park. Either one answers it. The blue tent is a campsite, and the blue P is a car park. Both are tourist symbols, which is why they are blue. A red dashed line also crosses the square from north to south. On a one to fifty thousand map, that is a public footpath.

Every feature on the map is either physical or human, and the test is who made it. A physical feature is natural, made by nature and not by people. On a map that means relief, the height and shape of the land, and water, such as rivers, lakes, marsh and waterfalls. A human feature is anything people have built or changed, from a village or a railway to a footpath worn by walkers. When a feature looks natural, ask one question: did people make it? If they did, it is human. Try the test on a reservoir, a lake that fills a valley behind a dam. Is a reservoir a physical feature or a human one? It's human. People built the dam to store the water. A quarry and a plantation pass the same test. A quarry is dug into rock, but people dug it. A plantation is trees, but people planted them in rows. A steep slope often has no symbol of its own. Brown contour lines packed close together show it, and a slope is physical, because nobody made it. What contours tell you about height has a video of its own, on contours and spot heights, so close together means steep is all you need here. Now two squares of a one to twenty-five thousand map, two nine three four and three oh three four. They hold a river flowing south-east with a waterfall, and contours close together on its west bank. There is a spot height of two hundred and sixty-two metres, a quarry, a farm, a minor road, and a footbridge over the river. Sort them: which two are physical, and which two are human? Physical first: the river with its waterfall, and the steep west bank. Human: any two of the quarry, the farm, the minor road and the footbridge. Now a different one: is the high ground at the spot height physical or human, and why? Physical. The dot is only the map's mark, but the high ground it marks is natural relief, and nobody made it. One examiner's report saw students improve at this, but still records "some confusion about what constitutes a physical feature". The habit that clears the confusion is asking, for every feature, whether people made it.

Reading the right square comes before reading anything in it. A four-figure reference names the square whose bottom-left corner, its south-west corner, is the point where its two lines cross. If that feels shaky, the video on grid references and scale covers it. Picture where easting fifty-six crosses northing twenty-one. In the square to the north-east of that crossing is a quarry symbol. One whole square further east sits a campsite. One whole square further north sits a place of worship with a tower. South-west of the crossing sits a youth hostel. Option A is the campsite with its blue tent. Option B is a place of worship with a tower. Option C is the quarry symbol cut into rock. Option D is the youth hostel near the crossing. Which feature is in grid square five six two one? It's C, the quarry. The crossing is the bottom-left corner of the square to its north-east, and that is where the quarry sits. The campsite is in five seven two one, one square east. The place of worship is in five six two two, one square north. Each of those is a real symbol in the wrong square. One examiner's report names the two skills in a question like this: "This question involved assessing the candidates' ability to use 4 figure grid references and interpreting the map key." The report adds that it is a skill to practise. The habit is to find the crossing, move north-east into the square, and only then open the key. Describing a feature from the map takes three things: what it is, where it is, and one detail the map shows about it. For the river in square two nine three four, that might be: a river flowing south-east, with a waterfall, in the west of the square. One examiner's report says a significant number of students did not use the OS map at all. They copied the information from the resource box, the printed text beside the map, instead. Instead, take the evidence from the map, in the key's own words, so swamp becomes marsh beside the river, with where it is. Tourist symbols are spotted the same way. What a cluster of them says about an area is the job of the video on reading a whole landscape. If your course has you study UK landscapes such as coasts, rivers or glaciers, each one's map features have a video of their own. Back to the cottage near Featherby. Read against the key, the three symbols within a kilometre are a quarry, a railway line and a large caravan site. Does the map back up the advert's peaceful countryside? No. Diggers, trains and a busy holiday park all bring noise and traffic, and the map showed all three before anyone booked.

Over to you for the recap, one question at a time.

Which square does the reference three four one two name?

The square north-east of where easting thirty-four crosses northing twelve.

Now, a dam across a valley: physical or human?

Human, because people built it, however natural the lake behind it looks.

Another: on a one to fifty thousand map, what is a red dashed line?

A public footpath, a right of way, which is printed green on a one to twenty-five thousand map.

A different one to finish: what three things describe a map feature?

What it is, where it is, and one detail the map shows about it.

That is how a family near Featherby could read past an advert: three small symbols, and a key that says what they are.

If the key feels like yours now, a thumbs-up says you're solid on this. If it hasn't landed, save it and return to it, because it comes with the questions.

Next in the chapter is Contours, spot heights, gradient and isoline maps. Hopefully that's next in your feed, but if not, search for ScholaFly G E oh two, oh three.

Every other video is on scholafly.com too, easy to search by video code or by keyword. Whatever you're revising, go there and have a look, or, watch the next video.