Friday, December 11, 2009

What Does A Contour Map Show

What Does a Contour Map Show?


Contour maps are two-dimensional illustrations used to show a land's elevation points and measure distance above and below sea level. They have scientific and recreational uses and range from very simple maps to more complex ones.


Features


A contour map is made up of contour lines and depicts the shape of land surface. A contour line is an imaginary line that connects points with the same elevation. Contour lines are referred to being above or below sea level. Put together, multiple contour lines can create a map of a land's surface called a topographic map.


Function


A contour map is used to show elevations on a two-dimensional plane. According to PhysicalGeography.net, contour maps "use a variety of symbols to describe both natural and human made features such as roads, buildings, quarries, lakes, streams and vegetation." The maps are used for recreational activities such as hunting and fishing, as well as for surveying, urban planning and resource management.


History and Production


The United States Geological Survey has been making contour topographical maps for the United States since 1879. These contour maps, like most complex ones, are designed using index contours. This means that every fifth contour line is bold and labeled with an elevation number. This avoids having to clutter the maps by labeling every line with an elevation number.


Significance


Contour maps are effective for displaying the landscape of a space. Contour lines that are spaced closer together show a very steep landscape. In contrast, those contour lines spaced farther apart identify a landscape that is flatter with a more gentle slope. In addition, valleys are shows with upward V curved lines and ridges are depicted with downward V lines.


Make One


It can be difficult to explain in words alone construct a contour map. The video at the link in Resources won the National Curve Bank's 2008 Renie Award for the Best Deposit of 2007 and provides a digital image of construct a contour map.







Tags: above below, above below level, below level, complex ones, construct contour, contour line