Monday, June 12, 2017

The Tools of Geography

The Tools of Geography (5 tools of geography)
To develop these five basic themes, geographers use a wide variety of tools. These tools include such modern and sophisticated items as aerial photographs, satellite images, and extremely intricate computer programs. However, a geographer's most basic and essential tools globes and maps have been used for centuries. Globes and maps, of course, are very familiar objects. You have seen them in your classroom or in the school library, and perhaps also in your home. Globes and maps are essential to the study of geography because they provide fairly accurate representations of Earth. However, globes and maps are not perfect models of Earth, and, therefore, each has advantages and disadvantages as a geographical tool.

The most important advantage of a globe is its shape. It is the only model of Earth that is spherical. Because a globe's shape follows the shape of Earth, the landmasses and bodies of water shown on it are correct in terms of shape and relative area. A globe also accurately shows distance and direction from one place to another.

In spite of its accuracy, the globe has some limitations. To begin with, a globe is bulky and awkward to carry. In addition, a globe does not allow you to see the entire Earth at once. For example, if you look at South America, Australia is hidden from your view. When you turn the globe to find Australia, South America is not visible. A globe's greatest problem, however, is that it lacks detail. Even the largest globes could not show the detailed features of the ancient Nile Valley. There would be no way to indicate the location of each of the 35 major pyramids that stand near the Nile River, the huge stone figure of the Sphinx, or the numerous irrigation channels and reservoirs used by the farmers of the region.

In contrast, the intricate details shown on maps make them useful to geographers. Through the use of symbols and colors, a huge range of information can be shown clearly on a map. By comparing maps, geographers can see movements, the effects of human-environment interactions, and the locations of various physical and cultural regions. In addition, maps are far more manageable than globes. They can be rolled or folded, and therefore they are easy to carry.

Still, maps do have one serious drawback: they are never totally accurate. Regardless of the skill of the cartographer, or map- maker, no map can accurately show the qualities of shape, area, distance, and direction at the same time because mapmaking involves recording on a flat surface what is curved on Earth's surface.

To appreciate the problems faced by cartographers, place a piece of paper directly over one of the Great Lakes of North America on a globe. Now trace the outline of the lake onto your paper. You should be able to trace its outline accurately without once bending or twisting your paper. Next, try tracing the outline of the entire North American continent. You can see immediately that some cutting or folding of the paper is required. Otherwise, you will drastically distort the outline of the continent. On the other hand, in cutting or folding the map, you create other distortions.

Distortion, then, is a major problem for cartographers when depicting large areas of Earth's curved surface on a flat map. Since maps cannot accurately show all four kinds of map information shape, area, distance, and direction at the same time, cartographers must decide which information they want their maps to distort least. Cartographers use a variety of projections methods by which Earth's surface is recorded, or projected, onto paper to create flat maps.

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