|
back of most of these maps is an excellent diagram showing a landscape in relief drawing and in contour topography. A contour is a line every point of which is at the same elevation. The shore line at mean low tide is the zero contour for all United States surveys and maps. If the coast has a ten-foot tide, the water will follow up each inlet and cross each beach to establish, in effect, a new contour line, ten feet higher. Ten feet would then be the contour interval. The interval between contours usually varies according to the scale of the map and roughness of the country, but is uniform throughout a particular map. |
|||
|
