A map can defined as a representation of part or the whole surface of the earth. The distinctive feature that distinguishes the topographical map is that the shape of the Earth’s surface is shown by the use of contour lines. Contours refer to imaginary lines that connect points of equal elevation on the land surface above or below a reference surface, for example, the sea level. The objective of the paper is to provide a brief definition of topographical maps, their use and importance in human daily lives.
Contours play a crucial role by making it possible to measure the height of mountains, steepness of the slope, and the depth of the oceans. There are some facts about contours below:
- Contour lines are always represented using a brown color. The ones that are blue in color are used to show water masses.
- Every fifth contour that is presented is thicker that the rest and their elevation is indicated in meters in every break point.
- Each contour is of the same elevation, irrespective of where it goes through.
- Two or more contours cannot intersect or cross one another at a point. However, they are closer in a steep area and much far from each other on a fairly flat surface.
- Contours that go round and make circles while increasing in elevation toward the center represent a hill or a mountain.
A topographical map shows much more than contours. The map portrays symbols that are used to represent such physical features as vegetation, streams, buildings, and streets. The symbols used in such representations are constantly being reviewed to better relate to the features that are being represented. Moreover, it is crucial to improve their readability and appearance, which will then reduce the cost of production.
Subsequently, symbols in a map can be used to represent the same or closely related features. A classic example is the representation of roads, built-up areas, cities, drainage patterns and systems.
Reading Topographical Maps
The interpretation of the areas, colored lines, and other key symbols that are utilized in a map is the preliminary stage in the process of learning how to read and use topographical maps. Features on the map are usually shown through the use of areas, lines, and points taking into consideration the extent of the feature as well as its size. For instance, small black squares are used to show the individual houses. Moreover, the larger buildings on a given area and their actual shapes are usually mapped. Conspicuous features like city halls, post offices, and churches are usually shown within a tinted area.
While one studies and explores a topographical map, they can be in a position to clearly notice diverse features marked in various colors like a blue color for seas, oceans, and lakes. A green color, on other hand, represents the vegetation on the area covered by the map, while a gray or red color is usually used to represent the built-up areas. In essence, numerous physical features are shown using lines that may be curved, dashed, dotted, or straight. Different colors on the lines are also of paramount importance; hereby, brown lines show contour lines, a blue color is used for hydrographic features like rivers, streams, and lakes and black is usually used for roads, boundaries, and trails.
In reality, a topographical map can then be perceived as a two-dimensional representation of the Earth’s surface which typically happens in a three-dimensional setting. Canadian topographical map with a scale of 1:50000 is the one that is normally used.
A topographical map has the following:
- Map name: This is the title of the map or the place that the map covers. It is found to be in the upper-right hand side of the map.
- Location: This is shown by a rectangle at the left hand side of the map. It gives the specific location from which the map was extracted.
- A scale: This is normally situated at the bottom side of the map. It exists in both ratios like 1:50,000 (that can be interpreted as 1 centimeter on the map represents 50,000 centimeters on the actual area) and the bar scales in miles. In essence, a scale is the ratio in distance that exists between two different places. In most cases, it is expressed as a ratio.
- The coordinates: They appear on both sides of the map and contain longitude and latitude. An example is given as 36 degrees north and 95 degrees west.
- Direction: There is a diagram on every map that is situated toward the left hand side corner of the map and it always points to the true north.
Information on a Topographical Map
The features that are usually represented on a map are grouped into the following:
- Relief: Features represented in this group include depressions, mountains, slopes, and valleys as defined by contours.
- Hydrography: The features that appear in this group are falls, rapids, swamps, streams, rivers, and lakes.
- Vegetation: This includes all the green vegetation cover on the map like plantations and forest cover.
- Transportation: Includes all the features that are associated with transport and/or human movement. Examples of features that constitute this group include seaplane anchorages, roads, airports and/or airfields, bridges, trails, and railways.
- Culture: Features that this category is comprised of are power transmission lines, pipelines, buildings, towers, and urban development.
- Boundaries: Includes all the boundaries that are covered on the map like geographical, recreational, administrative, territorial/provincial, as well as international boundaries that represent spans across different nations.
- Toponymy: This includes the names of the places, boundary names, water feature names, and landform names.
Uses of Topographical Maps
- A topographical map is used for navigation purposes by airlines, sea ships, and boats in order to maintain their course and avoid losing the direction. Through maps, pilots can easily interpret the height of different physical features like tall mountains to avoid them when flying at the same altitude, which would lead to a crash. Pilots also use maps in devising the flight plan, thereby being in a position to calculate the amount of fuel that can last them throughout the flight. It also helps them in calculating the estimated time of flight.
- Topographical maps are used in mapping resources such as mining grounds and vegetation. Thus, maps are used in mapping various resources on the earth surface like minerals (diamonds, gold, silver, quarry, limestone, soda ash). Apparently, this will insure that their exploitation can easily be conducted because of prior plans. Through this mapping, the government can easily pinpoint the areas that have natural resources as well as the type of these resources and hence can plan their exploitation process.
- A topographical map is used in planning, especially during the construction of airports, pipelines, highways, and houses. In most cases, airports are built in a relatively flat area with a wide field of view and far from mountains to insure that both the taking off and the approaching aircrafts can easily be seen and monitored to avoid collisions, which are normally fatal.
- Topographical maps are used in determining boundaries, which are a key element in everyday life of an individual. Boundaries can start from the society where each family is entitled to a certain piece of land, and boundaries can grow to a larger extent that separate nation or state from another one. Therefore, topographical maps are of national importance since they determine each and every person’s belonging to a certain country or a certain continent.
- Map reading skills are of paramount importance to fishermen in the deep seas, geologists looking for minerals far away, and engineers in their day-to-day construction works. Geologists use maps in order for them to gain easy access to forgotten and abandoned cemeteries, towns and post offices.
From the above insight into topographical maps, functions and utility of these maps in the day-to-day operations cannot be underestimated. The most essential role of maps is that they are the centerline of navigation of aircrafts and ships in the sea. Topographical maps are also of great importance in that they give a clear-cut representation of boundaries that could be existing between societies, communities, districts, countries, states, as well as continents. Thus, this reduces the possibility of conflicts, especially when one nation is trying to expand its boundary in order to benefit from given natural resources like diamond, gold, and copper. Some of the basic pieces of information enclosed in a topographical map include relief features, vegetation, natural resources, settlements, and towns. Compass and direction are key elements for one to understand the area covered by the map. Symbols are used in a topographical map to represent certain objects. In order to use topographical maps, one has to understand key symbols.