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geography-161018150952.pptx FOR CLAS 8TH
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- 2. We have learntin the previous chapter about the advantages of a globe. However , globe has limitations as well. A globe can be useful when we want to study the earth as a whole. But, when we want to study only the part of earth, as about our country, states, districts, towns & villages, it is of little help. In such situation we use maps. A map is a representation or a drawing of the earth’s surface according to a scale. But it’s impossible to flatten a round shape completely. We find that maps are useful to us for various purposes. One map shows a small area and a few facts. Another map may contain as many facts as a big book. When many maps are put together we get an Atlas book. Atlases are of different sizes, measurements drawn on different scales. Maps provide more information than the globe. They are of different types. Some of them are described below: Maps
- 3. Physical Map Maps showingnatural features of the earth such as Mountain, Plateaus, Plains, Oceans, Rivers etc. are called PHYSICAL or RELIEF MAP. POLITICAL Map Maps showing cities, towns & villages & different countries & states of the world with there boundaries are called POLITICAL MAP. Thematic Map Some map focus on specific information; such as road map, rainfall maps, maps showing distribution of forest, industries etc. are known as THEMATIC MAP.
- 4. SKETCH A SKETCH isa drawing mainly based on memory and spot observation and not to scale. Sometimes a rough drawing is required of an area to tell where a particular place is located with respect to others places. Supposes, you want go to your friend’s house, but you don’t know the way. Your friend will make a rough drawing to show the way to his/her house. Such a rough drawing is drawing is drawn without the scale, & is called a SKETCH MAP.
- 5. plan A PLAN isa drawing of a small area on a large scale. A large scale map gives lots of information, but they are certain things which we may sometimes want to know sometime. For example the length & breadth of a room, which can’t be shown in the map. At that time, we can refer drawings drawn to scale is called a PLAN.
- 6. Distance There are THREEtypes of COMPONENTS OF MAPS . They Are: - DIRECTION SYMBOL Components of Maps
- 7. Maps are drawingwhich reduce the entire world or a part of it to fit on a sheet of paper. Or we can say maps are drawn to reduced scale. But this reduction is done very carefully so that the distance between the places is real. It can only be possible when a small distance on paper represents a large distance on ground. Therefore, a scale is chosen for this purpose. Scale is the ratio between the actual distance on the ground and the distance shown on the map. For example, the distance between your school and your home is 10 Km. If you show this 10 Km. distance by 2 Cm on a map, it means 1 Cm is 5 Km on the ground. The scale your drawing will be, 1 Cm. is equal to 5 Km. Thus, scale is very important in any map. If you know the scale, you will be able to calculate the distance between any two place on a map. When Large areas like continent or countries are to be shown on a paper, then we use small scale. For example 5 Cm. on the map shows 500 Km. of the ground. It is called a SMALL SCALE MAP. When a small area like village or town is to be shown on paper, then a use a large scale, i.e. 5 Cm on the map shows 500 Meter Only on the ground. It is called LARGE SCALE MAP. Distance Back
- 8. DIRECTION Back Most maps contentan arrow mark with the letter ‘N’ at the upper right hand corner. This arrow shows the North Direction. It is called the North Line. When you know the North, you can find out other directions, for example East, West and South. There are major directions, North, South, East and West. They are called CARDINAL POINTS. Other four intermediate directions are North-East (NE), South-East (SE), North-West (NW) and South-West (SW). We can locate any place more accurately with the help of these Intermediate Directions. We can find out the direction of a place with the help of Compass. It is an instrument used to find out Main Directions. Its magnetic needle always point towards North and South Directions.
- 9. SYMBOL Back It is thethird important component of a map. It is not possible to draw on a map the actual shape and size of different features such as buildings, roads, bridges, trees, railway lines or a well. So, they are shown by certain letters, shades, colours, pictures and lines . These symbols give a lot of information in a limited space. With the use of these symbols, maps can be drawn easily and are simple to read. Even if you don’t know the language of an area and therefore cannot ask someone for directions , you can collect information from maps with the help of these symbols. Maps have a universal language that can be understood by all. There is an international agreement regarding the use of these symbols. These are called CONVENTIONAL SYMBOLS. Various colours are used for this purpose. For example, generally blue is used for showing water bodies, brown for mountain, yellow for plateau and green is used for plains. Click Here for some Symbols
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