Читать книгу Geography For Dummies - Jerry T. Mitchell - Страница 96

The basic function of maps is to show how particular phenomena are distributed over all or part of the world. Cartographers (mapmakers) communicate these and other kinds of information in part by incorporating into their maps a standard set of elements whose purpose is to help the map-reader get the message.

An easy way to remember these elements is with the acronym TALDOGS:

 Title: The title conveys the subject of the map and is the first thing a map-reader should look for. Ideally, its wording is simple and accurate. If the title confuses you, then that is probably more of a comment on the cartographer’s communication skills than your intelligence quotient.

 Author: Knowing who made the map might say something about the map’s credibility. Are you more likely to trust a map made by the National Geographic Society or one you found online created by joebubba12@email.com (that’s right, we just made that email address up, so no writing in, Joe!)?

 Legend: Maps commonly convey information with the aid of symbols whose meanings may be uncertain. Thus, the cartographer always provides a legend (or key) that contains and defines the symbols found on the map.

 Date: Every map in print is out of date once printed — the world changes that fast. Newer digital mapping technologies are making this a problem of the past as we can update spatial data more quickly. However, knowing when data is collected can help us in making spatial and temporal comparisons.

 Orientation: Orientation is the alignment of the map with respect to cardinal directions: which way are north, south, east and west? The standard rule is that north is towards the top of the map, but not every layperson knows the rule and not every map follows it. Accordingly, many maps include a direction indicator, minimally a north-pointing arrow.

 Grid: Many maps contain a couple of labeled grid lines of latitude and longitude (see Chapter 3) in order to convey the global context of the mapped area. If the cartographer has reason to believe that the map reader is intimately familiar with the mapped area, or if previous maps have indicated the global context of the mapped area, then grid lines may be omitted.

 Scale: Scale (described more fully in the following section) provides information about the actual size of the area shown on the map. Typically, this is achieved with a small ruler-like entry on a map that equates distance in miles and/or kilometers with measurement in inches and/or centimeters.