Why are topographic maps commonly used

The map legend allows you to unlock the topographic map as it provides you with all the information you require when trying to decipher the meaning behind all the symbols and colours found on your map.

Figuring out what your map symbols mean, allows you to better understand your surroundings when using a topographic map. Most people encounter topographic maps in their recreational lives, when planning a trip into the wilderness or back-country as well as navigating their way around wilderness areas.

December 14, 3 min read. December 09, 5 min read. What Are Longitude And Latitude? In a nutshell? They are the joint axis on any map that, when combined, will provide the exact coordinates of anywhere in the world.

Also in Geo Candy. A GIS portfolio is basically a compilation of materials that documents your work, skill and experience. Hatched concentric circles indicate a depression, as seen in the Figure below. The hatch marks are short, perpendicular lines inside the circle. The innermost hatched circle would represent the deepest part of the depression, while the outer hatched circles represent higher elevations. V-shaped expanses of contour lines indicate stream valleys. Where a stream crosses the land, the Vs in the contour lines point uphill.

The channel of the stream passes through the point of the V and the open end of the V represents the downstream portion. If the stream contains water, the line will be blue; otherwise, the V patterns indicate the direction water will flow.

In the map of Stowe, where does a stream run downhill into a lake? Scales on topographic maps indicate horizontal distance. An animation showing contour lines and the slopes they represent. The bathymetric map in the Figure below is like a topographic map with the contour lines representing depth below sea level, rather than height above. Numbers are low near sea level and become higher with depth. Bathymetric maps help oceanographers visualize the landforms at the bottoms of lakes, bays, and the ocean as if the water were removed.

Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. A geologic map shows the geological features of a region see examples in Figure below and Figure below.

One of the first uses of topographic maps was in the eighteenth century when the British military carried out detailed surveys of land. Pioneers in America also used and created topographic maps as they began to explore more of the country and expand their geographical knowledge of Western America.

Topographical engineers used topography to plan the routes for the Pacific Railroad , a railroad that today spans over 32, route miles. Topography has come a long way since the eighteenth and nineteenth centuries.

Nowadays, topographic maps have a number of uses. For example, they can identify mining opportunities, potential pond sites, and hiking routes. The most common use, though, is in urban planning. Large-scale building projects and highway planning agencies need to take into account the contours of the land to create structurally-sound buildings and efficient road routes.

Topographic maps are much more accurate than they used to be because of the way we create them. The maps are made using point cloud data — a collection of points or 3D coordinates representing a 3D object or landscape. LiDAR collects measurements using laser light pulses, whereas photogrammetry involves photographing land from above and calculating measurements from the photos. Surveyors may use one of these techniques or combine the two to gather point cloud data.

It is important to note that a map is merely a two or three dimensional representation of the physical environment at a given time. Therefore, a map will never be entirely up to date. Changes to the landscape and cultural features regularly occur such as roads, vegetation, and buildings , resulting in maps becoming dated, although the rate of obsolescence varies depending upon location. Geoscience Australia develops and maintains topographic maps and data for a variety of applications.