The Language of Maps

a model such as this might be thought of as a giant relief map of a certain area seen from above the model looks like an aerial view of the real thing doesn't it the small lake looks like a lake see the islands in the lake see the airport and the roads what else do you see that you recognize trees streams you know what this is how about this it's the same thing it's a dam only this is a symbol for a dam the way it appears on a map symbols are the picture language of maps a dam a river a bridge a road into school the map maker uses these symbols to give us information some symbols are easy to recognize because they look like what they represent other symbols have to be memorized like this one showing the direction for north we need to know directions to know where we are to become oriented this symbol tells about distance we call this the scale for a mile the more you know about the symbols of a map the more useful the map becomes to you if we take away the symbols for the man-made objects a map can still tell us a lot about where we are and what we will see if we explore you will notice that the lines in nature are very seldom straight lines nor are the shapes regular shapes each turn of the river is a little different each tree has a slightly different form the edges of the forest and the ridges and the valleys are rough and irregular here we can see what the poet means when he speaks of the river winding its way to the sea so when you see an irregular line on a model or a map it often symbolizes a dividing line drawn by nature and then traced by the map maker one of the most common of such lines is the dividing line between the land and the sea we call such a dividing line a shore line or a coastline from here a coastline would be easy to find wouldn't it that's right it's the place where the land and the water meet but how about this drawing if the shoreline is here and here how would we show it on a map seen from above a shoreline looks pretty flat even so it's easy to tell the land from the water isn't it the colors are different and since the water looks blue let's use blue for the water in our drawings a make-believe line called the datum plane separates the water below from the land above let's color the land brown we are adding to our picture symbols color symbols and on a map they look like this to tell how deep the water is and how high the land is let's add to the color symbols line symbols called contours or contour lines contour lines are drawn at even intervals here every 10 feet below the water line and every 10 feet above for the deepest part of the water let's use a dark blue this color will represents water 20 to 30 feet deep from 0 to 10 and from 10 to 20 let's use lighter shades of blue on our map they will look like this for the highest layer of land a light-brown is used and the brown gets darker as it gets closer to the water a map using colors and contours looks like this even without the numbers if you understand the symbols you can quickly tell where the water is deepest and the land highest downhill uphill and where the contour lines are closer together the hill is steeper and this is a good thing to know because looks can be deceiving even on the model this doesn't look like much of a hike does it but what appears to be flat is actually rough and uneven without contour lines or color symbols you might not know that in order to make this walk you'd have some climbing to do up one hill and down another at the bottom of which is a stream with no bridge you'd have to wade the stream and then climb an even steeper Hill on the other side what looked like a short walk might take a long time especially if half of it is uphill and the other half down what about the towns and cities where so many of us live have you ever been up in a helicopter where you could look down and see the houses and other buildings below if you were going to make a map how would you show a heavily populated area such as this it would all depend on how big the map was wouldn't it and how much we wanted to show if we were making a model or a giant relief map we could show our town like this the symbols would look very much like what they stood for this would be known as a large-scale map in other words the map is large enough and the area shown is small enough to allow the symbols to look like what they stand for but not all maps are like this nor do they need to be we may be interested in a larger area if so the scale for our map must become smaller it becomes less important for the houses and buildings to look so much like what they are we may be more interested in the streets and the highways approaching the town or we may be interested in the land that surrounds the town you will notice that the more of the area shown the less like a town our symbol becomes on maps that show very large areas a town even a city may be shown by just a small dot now we see that a small amount of the map represents a lot of territory therefore we say it is a small scale map but now suppose we were not interested in the towns but in the rainfall of the United States the mapmaker could very easily give us such information by simply adding to his map what we call a legend a legend tells us what sign language is used by the person making the map to give us special information if you were moving from one part of the United States to another and you wanted to know about the rainfall in the area of your new home a map such as this could tell you what to expect in these areas you could expect lots of rain lawns and trees and flowers would be plentiful but how about here very little rain you would be moving to a desert country and that can also tell us about temperature elevation prevailing winds almost anything can be told with maps by the use of symbols even about crops transportation industry and people it all depends on what the map maker wants to say so the next time you look at a map see how much more it tells you when you learn what the symbol stand for when you learn the picture language of the map makers story concerning that part of the earth he is trying to represent