Transcript Document
A MAP is a simplified plan of a place seen from directly above. Maps play a very important part in Geography. We use maps to find out where places are and what exists on different parts of the Earth’s surface. Jacaranda - Humanities There are six (6) essential features to maps. By using the acronym BOLTSS we are able to remember these six (6) essential features. Border frame Orientation direction Legend key Title name Scale size Acronym is: A word formed from the first letters of other words. Source origin The edges of the map should be clearly shown. A common way to show the border is with a box around the edges of the map. The border should be ruled and stand out clearly from other text or illustrations that surround the map. Direction must be shown on maps. This is done by placing a COMPASS ROSE or a north arrow on the map. Most maps have NORTH towards the top of the map. Sometimes, however, maps are turned so that north is not towards the top of the page. A legend may also be called a key. It is an explanation of the meaning of all the symbols, colours and signs used to show features on a map, in a list format. The title of the map should tell us something about the map. It would be impossible to draw parts of the Earth to their actual size. So maps are drawn to a smaller size, with the shape of the features remaining the same. Scale can be shown in three ways: in linear form; as a ratio [1:100 000] and as a statement for example ‘one centimetre represents one kilometre’. (Find out more about: SCALES IN MAPPING) A good map will state where the information used to make the map, has come from, particularly the date. This enables the user to update the data shown, or obtain similar information. Alphanumeric grid reference A combination of letters and numbers that locate points on a map. Bearing An angle given in degrees and measured clockwise from north. Cardinal points The four main points on a compass which are used to give direction. I.e., North, South, East and West. Cartographer A person who draws maps. The science or practice of drawing maps. Cartography 1843, from French cartographie, from Medieval Latin carta + French graphie, from Greek -graphein "to write, to draw". Conventional symbols Standard symbols that are commonly used in maps. Distance The space between different locations. Distribution The general pattern shown by different things on the Earth’s surface. Geospatial skills The ability to identify, interpret and explain features and patterns in the environment and on different kinds of maps, photographs, satellite images and statistical data. Location Where something is found on the Earth’s surface. Magnetic compass An instrument which shows the direction of magnetic north. Mental maps and mud maps An image or idea in your head which locates the main features of a place with which you are familiar. Movement The change in location of things across the Earth’s surface. Oblique view A view from an angle. Orthophoto map This map is a corrected aerial photograph. Man-made and other features that are not clear are labelled on the orthophoto. Plan view The view from directly above. Region An area that has one or a number of distinctive characteristics. Satellite image Image of the Earth’s surface transmitted from an orbiting satellite. Spatial Relating to the distribution of features on the Earth’s surface. Spatial association Spatial change over time Spatial concepts Spatial intersection Spatial perspective Topographic map The relationship between the distribution of two or more features in a selected region. How the distribution of a feature has changed has changed from the past and how it is likely to change in the future. Key geographic ideas used by geographers to describe the world around them. How different features and processes affect each other and how they influence patterns. A view of the physical world made up spatial and other information available to describe and explain patterns at or near the earth’s surface. This map is a way to show mountains, valleys and aspects of a landscape by means of contour lines and intervals. • • • • • • About.com - Geography: What is a Map? Jacaranda Humanities: Chapter 6.3 Map Scales and Types of Scales Scales Methods The Compass and other Magnetic Innovations Three Types of Scale The MAGNETIC COMPASS was discovered by the Chinese in 200BC, during the Qin Dynasty. It is considered as the first documented self-registering instrument created by mankind that could be read using a precise scale. The COMPASS ROSE (as the WIND ROSE was known on early navigation charts) appeared on charts and maps beginning around the 14th Century. Elaborate ‘wind roses’ had 32 points , that kept with the tradition of the 32 classically named winds. Predecessor to the magnetic compass: ‘The Magnetic Compass’ was placed over ‘The Wind Rose’ to show NORTH. It is thought that the Portuguese improved the ‘wind rose’ to a sixteen-point ‘wind rose’. Show Compass Points Return to ORIENTATION Predecessor to the magnetic compass: ‘The Magnetic Compass’ was placed over ‘The Wind Rose’ to show NORTH. Show text Information Return to ORIENTATION Map Scales The scale to which a map is drawn represents the ratio of the distance between two points on the earth and the distance between the two corresponding points on the map. Map Scales = Map Distance Scale Distance Linear Scale (also known as: Visual Scale, Graphic Scale and Bar Scale] Almost every map has a linear scale that can be used for measuring. It shows graphically the relationship between map distance and ground distance. A Linear Scale depicts scale using a line, with separations marked by smaller intersecting lines, similar to a ruler. One side of the scale represents the distance on the map, while the other side represents the true distances of objects in real life. By measuring the distance between two objects on a map and then referring to the graphic scale, it is easy to calculate the actual distance between those same objects. Return to SCALE More on SCALES Ratio Scales (also known as Representative Fraction (RF) and Fractional Method It is expressed as a numerical ratio of map distance to ground distance; it is usually written as 1/50,000 or 1:50,000, meaning that one unit of measurement on the map represents 50,000 of the same units on the ground. The fractional method for portraying the scale of a map uses a representative fraction to describe the ratio between the map and the real world. This can be shown as 1:50,000 or 1/50,000. In the examples below: • One inch equals one mile therefore, one inch equals 62,500 inches on the map; that in turn equals one mile in the real world. • One centimetre equals one kilometre therefore, one centimetre equals 100,000 centimetres on the map; that in turns equals one kilometre in the real world. Return to SCALE More on SCALES Statement Scale (also known as Verbal Scale, Direct Statement and Verbal Method) When a scale is expressed in words this is a Statement Scale (Verbal or Direct): 1cm = 100km Calculating scale on a map using this type of scale is easy. Simply measure the distance on the map and then follow the directions to calculate the actual distance. NOTE: Changing Scales The maps show the effects of scale changes moving "closer to" or "farther from" the earth. • A large scale map shows a small area with a large amount of detail. • A small scale map shows a large area with a small amount of detail.