by Matthew Brendal

Created on: May 22, 2008   Last Updated: May 30, 2008

Map scales are one of the first things you should be aware of when you are introducing yourself to topographic maps. Maps today are a treasure trove of wonderful symbols and scales. Reading a topographic map is just like finding a wonderful treasure of secret symbols. When maps were first made, they were drawn out on the ground. Perhaps later they were crudely inked on parchment. Today maps are very accurate precision tools to help find a travel route. But the most important piece of information on a map is the scale size. Scale is really nothing more than how many steps it would take to go from point to the next.

The scale will be written in both an equation form and graphically. The written scale will look something this: 1:125,000. The graphic or bar scale will probably have a separate bar for miles, feet and meters. The bar scale is a tool to make measurements of distance using a compass, string or ruler. The bar scale can be difficult to read and use sometimes. Usually it is broken into two scales. Several whole miles, thousands of feet or kilometers and then one side/section will be broken down into tenths. I'm sure if you study it for a minute it will become very obvious to you.

The scale on a map is a simple tool used to display the size ratio of the map coverage primarily for determining distance. A ratio is nothing more than a representation of a size of an object on a map, in relation to the object it represents. The rule of thumb using the scale on a map is this: The bigger the number 1:1,000 for example the smaller the scale. The larger the number, the smaller the scale. It just means one of any distance in real life is equal to 1,000 of those on the map.

Then there are the scales used in map making or cartography. Small, medium and large scale are defined by their ratio. A small scale map would be in the range of 1:10,000 to 1:25,00. A medium scale map would be in the range of 1:50,000 1:250,000. A large scale map would be any thing with a ratio larger than 1:500,000. A memory aid to remember the scale description is to remember that small scales have tiny ratio values such as 1:250,000 or 1/250,000 while larger ratios are 1:500 or 1/500.

Let us look at a simple mathematic equation using map scale to calculate the distance between two points on our map. That distance is say, 575 millimeters. We then take a look at the scale on that same map and multiply our distance by the scale denominator.

Known accumulated data: 575 mm distance from a map with

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