This is why cartographers use scale bars that compare a map distance to an actual distance. Not only do scale bars, ratio and stated scales can also show size and distance in a way that people understand, but inset maps help understand map scale. Similar to other cartographic elements used in maps, here are all the ways cartographers represent map scale in their work.
Ratio scales are one of the most common ways to depict scale on maps. It tells the map reader that one unit on the map is equal to a certain number of units in the real world. Example: Because cm is difficult to interpret, we convert it into an understandable unit. In this case, there are centimeters in a meter. The Marina del Rey harbor is represented by a small inlet on the map. In a large scale layer created to show just the County of Los Angeles boundary, the coastline for this area contains the highest level of detail, and a recognizable harbor is represented.
The examples of how the detail of a coastline changes depending on the scale of the layer helps to illustrate as well the importance of carefully considering the scale of any data used for mapping and spatial analysis. Small scale data inherently is less accurate and less detailed than large scale data.
Using small scale data for large scale analysis can lead to gross errors. Data created for small scale purposes should not be used in large scale maps. Large scale data unless generalized, should not be used in small scale maps.
Cartographic Resources — Resources for learning more about cartography and cartographic techniques. What is GIS? Representing Scale on a Map All maps will have an indicator of the scale of the map.
Bar scale showing graphically the ratio of map units to ground units. The top scale shows the comparable ground measurement in kilometers km and the bottom bar scale shows the comparable length in miles. Marina del Rey area on a small scale map.
This makes it very easy to set the scale to be the same as the current scale you are using. So if you choose this option when the current scale of the data frame in your map is ,, that value will appear in the scale field.
You can customize the standard scales that appear in the map scale list throughout ArcMap, along with the format with which scales are shown. When you click on Customize This List from the Scale drop-down list, the Scale Settings dialog box appears that allows you to build a series of map scale settings and to use a map scale list prepared by others. You can add and remove map scales by manually typing them or by clicking Add Current to add the current map scale to the list. You can also save your scale settings and share them with other users or load a scale settings file for use on your maps.
First, it is easy to use when figuring distances on a map since most map readers are used to working with rulers. Second, if the map is enlarged or reduced using some method of photocopying or screen display, the scale bar changes size in direct proportion to the physical size of the map. The other two scale indicators — verbal scales and representative fraction — on the other hand, will become incorrect when the map changes size.
Third, both kilometers and miles can be shown conveniently on the same bar scale. The scale bar should be subtle and it should not attract the attention of the map reader — instead they should have to shift their attention in order to find it on the page. Only use as many intermediate divisions are required. The scale bar should be thinner rather than thicker, and it should use thin lines for the bar and the ticks make sure you do this for all the lines that make up the scale bar including the ticks!
The font used to label the scale bar should be some of the smallest type of the page. Using more ticks than you need, thick lines, a wide scale bar and larger text unnecessarily complicates this map element and forces it to a higher level than it belongs in the visual hierarchy on the page. The optimal length of the scale bar is related to: 1 the amount of space on the page devoted to the map, and 2 the distances on the map that you expect the reader to measure.
The scale bar should shorter than the map itself. You can also design your scale bar to include an extension scale below which can be used for smaller distance determinations. Sometime you will see the extension scale to the left of the zero and sometimes it can be found as a greater umber of divisions to the right. An extension scale which shows finer subdivisions of the scale bar allows for smaller distance measurements. The scale bar is usually placed below the map, but this will depend on your page layout.
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