Topographic map scales. Ground area rivers lakes roads distances between features and so on must be shown proportionately smaller than they really are. Maps based on metric units use a scale of 125000 where one centimeter equals 025 kilometers. Geomart your expediated source for. Large is small simply defined scale is the relationship between distance on the map and distance on the ground.
They also publish specialty maps including geologic hydrologic and photoimage maps for a variety of uses. The proportion chosen for a particular map is its scale. The maps scale tells you how detailed your map is. Ground area rivers lakes roads distances between features and so on must be shown proportionately smaller than they really are.
For usgs topographic maps 124000 is the scale most often used. Today the usgs has more than 56000 topographic maps of the united states in various scales plus maps of the moon and planets. Performed at large scales these surveys are called topographical in the old sense of topography showing a variety of elevations and landforms. The usgs was entrusted with the responsibility for mapping the country in 1879 and has been the primary civilian mapping agency of the united states ever since.
A map scale. A 124000 scale for example means one inch equals 24000 inches in reality. From approximately 1947 to 1992 more than 55000 75 minute maps were made to. Selecting the appropriate scale depends on the size of the sheet of paper and the accurate placement of features.
Map is its scale. The best known usgs maps are the 124000 scale topographic maps also known as 75 minute quadrangles.