Samacheer Kalvi 9th Social Science Geography Solutions Chapter 7 Mapping Skills
Samacheer Kalvi 9th Social Science Geography Solutions Chapter 7 Mapping Skills
Tamilnadu Samacheer Kalvi 9th Social Science Geography Solutions Chapter 7 Mapping Skills
Mapping Skills Textual Exercise
I. Choose the correct answer.
Question 1.
The new phase in topographical surveying in the 20th century is ……
(a) toposheets
(b) aerial photography
(c) maps
(d) satellite imagery
Answer:
(d) satellite imagery
Question 2.
…… indicates the purpose or theme of the map.
(a) Title
(b) Scale
(c) Direction
(d) Legend
Answer:
(a) Title
Question 3.
Standard symbols that are used in maps to convey a definite meaning are called ………
(a) conventional signs and symbols
(b) coordinates
(c) grid references
(d) directions
Answer:
(a) conventional signs and symbols
Question 4.
Which one of the following maps show us a very large area with less details?
(a) Large scale
(b) Thematic
(c) Physical
(d) Small scale
Answer:
(d) Small scale
Question 5.
GPS consists of a constellation of ……… satellites.
(a) 7
(b) 24
(c) 3.2
(d) 64
Answer:
(b) 24
II. Consider the given statements and choose the right option given below.
Question 1.
Assertion(A): The points at which the vertical and horizontal lines of the grid intersect are called coordinates.
Reason(R): The lines that run horizontally and vertically are called Northings and Eastings respectively.
(a) Both (A) and (R) are true ; (R) explains (A)
(b) Both (A) and (R) are true ; (R) does not explain (A)
(c) (A) is correct; (R) is false
(d) (A) is false ; (R) is true
Answer:
(a) Both (A) and (R) are true ; (R) explains (A)
Question 2.
Assertion(A): The legend of a map does not help us to understand the information in a map. Reason(R): It is usually placed at the left or right comer at the bottom of the map.
(a) (A) is false ; (R) is true .
(b) Both (A) and (R) are true ; (R) does not explain (A)
(c) (A) is correct; (R) is false
(d) Both (A) and (R) are true ; (R) explains (A)
Answer:
(a) (A) is false ; (R) is true
III. Match the following:
Answers:
1. (e)
2. (d)
3. (b)
4. (c)
5. (a)
IV. Answer in brief
Question 1.
Name the different methods to represent the Earth. ‘
Answer:
The three methods in widest use are as follows:
- Projection on the surface of a cylinder
- Projection on to the surface of a cone
- Projection directly onto a flat plane, called planar or zenithal or azimuthal projection.
Question 2.
What is a map?
Answer:
A map is the basic tool of a geographer. It illustrates the earth’s surface Clearly and effectively through a combination of drawings, words and symbols. A map is a location guide.
Question 3.
What are the components of a map?
Answer:
Title, scale and directions are the three components of a map.
Question 4.
The distance between two cities A and B is 5 km. It is represented by a line of 5 cm on the map. Calculate the distance and give the answer in RF.
Answer:
Representative Fraction (R.F.) = Distance on the map / Distance on the ground Given, Distance on the map = 5 cm
Distance on the ground = 5 km
∴ R.F. = 5 cm / 5 km
Converting km to cm; 5 km = 500000 cm
So R.F. is 5 : 500000
i.e. R.F. is 1 : 100000
Question 5.
Mention a few surveying instruments.
Answer:
Chain, Prismatic compass, Plane table, Dumpy level, Abney level, Clinometre, Theodolite, Total Station and GNSS are some of the surveying instruments.
Question 6.
Define remote sensing.
Answer:
Remote Sensing refers to the observation and measurement of earthly objects without touching them. ‘Remote’ means far away and ‘Sensing’ means observing or collecting information. Remote sensing means acquiring information of things/places from a distance, using a variety of tools and methods.
Question 7.
What are the components of remote sensing?
Answer:
Components of remote sensing are:
- Energy source
- Transmission path
- Target
- Sensor
V. Give Reasons
Question 1.
Satellite imageries stimulate map making.
Answer:
- Satellite imagery refers to digitally transmitted images of the satellites. Therefore it can be easily integrated with software for improvement of images.
- Satellites circle the Earth, or remain geostationary and therefore, changes in weather or any other natural or man made modifications does not affect the functioning of Satellites.
Question 2.
Map is the basic tool of a geographer.
Answer:
With maps on hand, one can see the world in one sweep. A map is worth a thousand words. Maps are introduced with its components such as scale, signs and symbols. A map is the basic tool of a geographer. It illustrates the earth’s surface clearly and effectively through a combination of drawings, words and symbols. A map is a location guide.
Question 3.
Grid references are essential to find the exact location of places on a map.
Answer:
The location of a place can be simply defined by its latitude and longitude. In normal practice, latitude is stated first and then comes the longitude. The latitude and longitude of a place can be expressed in units of degree, minutes and seconds.
A grid is a set of lines with alphanumeric codes for defining a location on a map in many topographical sheets. The lines that run horizontally from left to right of the map are known as northings, whereas, the lines that run vertically from the top to the bottom of the map are called eastings. The points at which the vertical and horizontal lines of the grid intersect are called coordinates which are identified by numbers or letters.
Question 4.
Web cartography is one of the modern mapping techniques.
Answer:
The introduction of web mapping is a major new trend in cartography. The term Web cartography is connected with the design, production, display and use of maps over the Web. Various types of maps are present on the Web. Until recently cartography was restricted as it required relatively expensive and complex hardware and software as well as skilled cartographers and geomatics engineers.
Web based GIS has brought many geographical datasets, including free ones generated by OpenStreetMap and proprietary datasets owned by Navteq, Google, Waze, and others. A range of free software to generate maps has also been conceived and implemented alongside proprietary tools like ArcGIS. As a result, the barrier to entry for serving maps on the web has been lowered.
VI. Distinguish Between The Following:
Question 1.
Globe and Map
Answer:
| Globe | Map |
| It is a representation of the whole earth with clear marking of longitude and lattitude of all the places on earth. | A map illustrates the earth’s surface more clearly and effectively through a combination of drawings, words and symbols. |
Question 2.
Large scale map and small scale map
Answer:
| Large scale map | Small scale map |
| Large amount of detail is shown of a small area can be seen in a large scale map. | Small amount of detail of a larger area can be seen in a small scale map. |
Question 3.
Aerial photographs and satellite imageries
Answer:
| Aerial photographs | Satellite imageries |
| It covers a small area and needs permission from authorities. | It allows global coverage and does not require permission. |
| Revisits or repeatability involves extra cost. | Satellites circle the Earth; they can repeat and revisit easily. |
Question 4.
GIS and GPS
Answer:
| GIS | GPS |
| Geographic Information System is a computer-based tool for managing a large amount of data collected for a given geographic region through remote sensing, GPS and other sources. | GPS is the U.S. implementation of the world’s first and currently the most used Global Navigation Satellite System (GNSS) created by the U. S. Department Of Defense. |
| GIS finds its strongest use in resources management, telecommunications and urban and regional planning. | Weather forecasting, earthquake monitoring and environmental protection can be done effectively by using GPS. |
VII Answer in a paragraph:
Question 1.
What do you mean by the term ‘scale of the map’? Explain its classification.
Answer:
Scale makes it possible to reduce the size of the whole earth to show it on a piece of paper. A scale is a ratio between the actual distance on the map to the actual distance on the ground. Scales can be represented in three methods. They are the Statement, Representative Fraction (R.F) and Linear or Graphical scale methods.
Statement scale
The statement scale describes the relationship of map distance to ground distance in words, such as one centimetre to ten kilometres. It is expressed as 1cm =10 km.
The Representative Fraction (R.F)
It describes the proportion or ratio of the map distance to ground distance. It is usually abbreviated as R.F. It is stated as 1/100000 (or) 1:100000. This means that one unit on the map represents 100,000 of the same unit on the ground. This unit may be an inch or a centimetre or any other linear measurement unit. Thus, Representative Fraction (R.F.) = Distance on the map/ Distance on the ground
Question 2.
Write a note on directions with a relevant diagram.
Answer:
Direction
Maps are drawn normally with north orientation. North direction in a map is always towards the North Pole of the earth. If you position yourself looking at the North Pole, on your right will be the east; your left will be the west; at your back will be south. These four main directions are called the cardinal directions. Direction is usually indicated on a map by a North-South line, with the North direction represented by an arrow head.
Question 3.
What are the three major functional segments of GPS? Explain about any one.
Answer:
The Global Positioning System (GPS) is a U.S. owned utility that provides users with positioning, navigation and timing services (PNT). This system consists of three segments: the space segment, the control segment and the user segment.
Space Segment: This is formed by a Satellite Constellation with enough satellites to ensure that the users will have at least 4 simaltaneous satellites in view from any point at the Earth Surface at any time.
Question 4.
Bhuvan has tremendous uses for scientists, policy makers or the general public. Justify.
Answer:
Bhuvan (Sanskrit for Earth) is a free internet based computer application launched by the Indian Space Research Organization (ISRO) on August 12th 2009. It enables visualization of Indian Remote Sensing (IRS) images taken over a year ago, by ISRO’s seven satellites, including CartoSat-1 and CartoSat-2. Using Bhuvan connected to Internet, one can explore places of interest, scenes of events in the news or parts around the world they may never visit in person, by either entering the names of places or co-ordinates (latitudes and longitudes). Bhuvan has tremendous uses for scientists, academicians, policy makers and the general public.
Advantages
- Bhuvan, due to 3D rendering, gives the impression of moving through real space through the entire globe
- Students can use Bhuvan to understand subjects ranging from Sciences to History of places.
- It provides information on natural resources and timely information on disasters.
- Administrators use it for monitoring various developmental schemes.
VIII. HOTS:
Question 1.
Can you imagine a world without satellites?
Answer:
No, we cannot imagine a world without satellites.
- Our lives would change in so many ways. Millions of people would be affected as they can’t speak through mobile phones or send messages, TV shows would be missed, important informations cannot be passed on quickly and so on.
- Scientific studies would be greatly restricted.
- Army people would face difficulty in coordinating for international operations.
- Spying would be impossible.
- There will be navigation issues, communication issues, etc.
Question 2.
Imagine you are a cartographer. Plan and bring out a few ideas to improve your area.
Answer:
Cartographers are trained in aerial photography and in collecting survey data for preparing maps, charts and sketches.
They work to create detailed information maps based on survey data.
* Ideas to improve Chennai
- Maintaining the ecological process in Chennai.
- Balancing the essential infrastructures of the urban areas.
- Improving the connectivity in and around South Chennai from the main city.
- Improving Civic Services
Chennai corporation is set to upgrade its Geographical Information System (GIS) services. This was used for the creation of digital base and Utility mapping using GIS technology in 44,000 streets in Chennai.
(* Students can add their own creative ideas)
IX Map skill:
A. With the help of an atlas, mark the following on the outline map of Tamil Nadu.
a. The latitude and longitude of Chennai. .
b. Mark the city located at 10° N, 78° E.
c. Locate the city approximately on 11°N and 76°E.
d. Find the latitude and longitude of Kanyakumari and mark it.
Mapping Skills Additional Questions
I. Choose the correct answer.
Question 1.
The first ancient Greek to draw a map of the known World is ………
(a) Anaximander
(b) Gerardus Mercator
(c) Felix Nadar
(d) None of these
Answer:
(a) Anaximander
Question 2.
The foundation for map-making in India was laid during the …… period.
(a) Pre-historic
(b) Medieval
(c) Vedic
(d) Modern
Answer:
(c) Vedic
Question 3.
……. is a way of showing the spherical shaped earth on a flat piece of paper.
(a) Direction
(b) Grid Reference
(c) Projection
(d) Legend
Answer:
(c) Projection
Question 4.
……… symbols are used to indicate railways, roads, power lines, telephone lines in
mapping.
(a) Line
(b) Point
(c) Area
(d) None of these
Answer:
(a) Line
Question 5.
Maps produced by analysis can be used to pinpoint problem areas.
(a) GPS
(b) GIS
(c) GNSS
(d) DoD
Answer:
(b) GIS
II. Find out the correct statement.
Question 1.
Assertion (A): A linear scale is represented by a straight line divided into equal parts to show
what these markings represents on the actual ground.
Reason (R): This scale helps in the direct measurement of distance on the map.
(a) Both A and R are true; R explains A
(b) Both A and R are true; R does not explain A
(c) A is correct and R is wrong
(d) A is wrong and R is correct
Answer:
(a) Both A and R are true; R explains A
Question 2.
Assertion (A): Satellites do not collect large amounts of data of the entire area in a short span. Reason (R): Sensors in the satellites record the reflected and emitted radiation.
(a) A is wrong and R is correct
(b) Both A and R are hue; R does not explain A
(c) A is correct and R is wrong
(d) Both A and R are true; R explains A
Answer:
(a) A is wrong and R is correct
III. Match the following:
Answers:
1. (e)
2. (a)
3. (b)
4. (c)
5. (d)
IV. Answer in brief.
Question 1.
Give a short account of ‘Imago Mundi’ the Babylonian Map of the World.
Answer:
More commonly known as the Babylonian Map of the World, the Imago Mundi is considered the oldest surviving world map. It is currently on display at the British Museum in London. It dates back to between 700 and 500 BC(BCE) and was found in a town called Sippar in Iraq.
The carved map depicts Babylon at the centre. Nearby are places like Assyria and Elam, all surrounded by a “Salt Sea” forming a ring around the cities. Outside the ring, eight islands or regions are carved onto the tablet. The map is accompanied by a cuneiform text describing Babylonian mythology in the regions depicted on the stone.
Question 2.
Who is a Cartographer? What is Cartography?
Answer:
A cartographer is one who measures, analyzes and interprets geographical information to create maps and charts for political, cultural and educational purposes.
The art and science of map-making is called Cartography.
Question 3.
What do you mean by ‘Direction’?
Answer:
Maps are drawn normally with north orientation. North direction in a map is always towards ‘ the North Pole of the earth. If you position yourself looking at the North Pole, on your right will be the east; your left will be the west; at your back will be south. These four main directions are called the cardinal directions. Direction is usually indicated on a map by a North-South line, with the North direction represented by an arrow head.
Question 4.
What is Projection? Mention the three methods in widest use.
Answer:
A map projection is a way of showing the spherical shaped earth on a flat piece of paper.
The three methods in widest use are as follows:
- Projection on the surface of a cylinder
- Projection on to the surface of a cone
- Projection directly onto a flat plane, called planar or zenithal or azimuthal projection
Question 5.
Name the three types of Map Symbols.
Answer:
There are three types of map symbols;
- Point Symbols – buildings, dipping tanks, trigonometrical beacons
- Line Symbols – railways, roads, power lines, telephone lines
- Area Symbols – Cultivated lands, ponds, orchards and vineyards
Question 6.
What are the types of Maps?
Answer:
(a) On the basis of scale, maps can be classified into:
- Large scale maps: Large amount of detail; can only show a small area.
- Small scale map: Small amount of detail; can show a large area.
(b) On the basis of utility and purpose, they are classified as:
- General maps / Topographic Maps (physical and political maps)
- Thematic map (spatial variations of single phenomena)
- Special purpose maps (Braille maps for blind people, maps for neo literates, military maps, navigational charts, etc).
Question 7.
What is survey?
Answer:
Surveying is done to measure the angle, direction, area, height and distance of an object or place on the surface of the earth using instruments. Surveying techniques are used to obtain the field data and to prepare maps. A knowledge of surveying helps one in map-making, particularly in the preparation of physical maps.
V. Give reasons
Question 1.
The foundation for map-making in India was laid during the Vedic period.
Answer:
The foundation for map-making in India was laid during the Vedic period. Mahabharata conceived a round world surrounded by water. Surveying and map-making were an integral part of the revenue collection procedure in the medieval period. E.g.: Sher Shah Suri’s revenue maps and Rajendra Chola’s land survey techniques.
Question 2.
“If is not possible to show all the data of an area on a map”.
Answer:
The details that are to be shown may vary according to requirement. Therefore, it is essential to consider the scale and purpose while preparing maps.
Question 3.
“GPS helps in providing accurate transport data”.
Answer:
- GPS technology has tremendous applications in everything.
- It helps in military searches and rescue in wars.
- It can work as a reliable tourist guide (distance, route and direction)
VI. Distinguish between the following.
Question 1.
Maps and Cartography
Answer:
| Maps | Cartography |
| Maps are drawings of an area as seen from above. Maps can show a whole or part of the world. , | The art and Science of map-making is called cartography. |
VII. Answer in a paragraph.
Question 1.
What is Satellite Remote Sensing? Explain the
(a) components of Remote Sensing
(b) process of Remote Sensing.
Answer:
Satellite remote sensing is the science of collecting data about an object or area from artificial satellites orbiting the Earth. The term ‘satellite imagery’ refers to digitally transmitted images of the satellites.
Components of remote sensing
- Energy source
- Transmission path
- Target
- Sensor
Process of remote sensing
- The EMR (Electro Magnetic Radiation) or solar radiation is the primary source of energy for remote sensing.
- Sunlight travels from the sun through the atmosphere, before it reaches the earth surface. In the atmosphere, the sun’s rays are not obstructed by any object.
- When solar radiation falls on the earth’s surface, some of its energy is absorbed. While some is transmitted through the surface, the rest is reflected. Surfaces naturally emit radiation in the form of heat. The reflected energy travels from the earth surface back to space.
- Sensors in the satellite record the reflected and emitted radiation. Each surface/object possesses a characteristic spectral signature, a unique pattern of reflecting sunlight.
- The energy recorded by the sensor has to be transmitted to a ground station where the data are processed into an image.
- The processed image is interpreted either visually by human interpreters or by computer aided techniques called digital image processing to identify and distinguish between the different spectral signatures to get information about objects/places.
- Finally, we understand and apply the extracted information in mapping the area or assist in solving the particular problem.
Question 2.
Describe the
(a) Advantages of Remote Sensing
(b) Disadvantages of Remote Sensing
(c) Remote Sensing and Disaster Management
Answer:
(a) Advantages of Remote Sensing
- It is the only practical way to obtain data from inaccessible regions, e.g. Antarctica, Amazon forest.
- It helps in constructing cheap base maps in the absence of detailed land surveys.
- It detects the spread of natural calamities such as flood, forest fire and volcanic eruption, so that immediate rescue operations and planning can be carried out.
(b) Disadvantages of Remote Sensing
- It is difficult to prepare large scale maps from obtained satellite data.
- The technique is very expensive for small areas requiring one time analysis.
(c) Remote Sensing and Disaster Management
Remote sensing technology is highly used in disaster management to study the effects of earthquakes, tsunamis, cyclones, volcanic eruption, floods and wildfires. The preliminary data is retrieved from satellites like LANDSAT, CARTOSAT, OCEANSAT, etc. Fire and flood details can be extracted and delivered to relevant authorities within two hours of satellite image capture. E.g. major earthquakes in China and New Zealand, bushfire in Victoria and floods in Kerala. Dynamic phenomena such as flood, movement of wild animals, shoreline changes, finding lost ships and planes. Researchers use satellite imageries for these.
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