CHAPTER 1: Introduction to Maps NCERT SOLUTION CLASS 11TH practical work in geography | EDUGROWN NOTES

VERY SHORT QUESTION AND ANSWER:

Q1.What is map generalisation?
Answer:
As maps are drawn at a reduced scale to serve a definite purpose, it is the job of a cartographer is to generalise the map contents. In doing so, a cartographer must select the data relevant to the selected theme and simplify it as per the needs. It is called map generalization. Every map is drawn with a definite objective. For example, a general purpose map is drawn to show information of a general nature such as relief, drainage, vegetation, settlements, means of transportation, etc. Similarly, a special purpose map exhibits information pertaining to one or more selected themes like population density, soil types or location of industries. It is, therefore, necessary to carefully plan the map contents while the purpose of the map must be kept in the forefront.

Q2.Why is map design important?
Answer:
Map Design is very important as it involves the planning of graphic characteristics of maps including the selection of appropriate symbols, their size and form, style of lettering, specifying the width of lines, selection of colours and shades, arrangement of various elements of map design within a map and design for map legend. The map design is a complex aspect of map-making and requires thorough understanding of the principles that govern the effectiveness of graphic communication.

Q3.What are different types of small-scale maps?
Answer:
Small-scale maps are divided into two types:

1. Wall Maps: These maps are generally drawn on large size paper or on plastic base for use in classrooms or lecture halls. The scale of wall maps is generally smaller than the scale of topographical maps but larger than atlas maps.
2. Atlas Maps: Atlas maps are very small-scale maps. These maps represent fairly large areas and present highly generalized picture of the physical or cultural features. Even so, an atlas map serves as a graphic encyclopaedia of the geographical information about the world, continents, countries or regions.

Q4.List out two major types of large-scale maps?
Answer:
Large-scale maps are divided into two types:

1. Cadastral maps: The term ‘cadastral’ is derived from the French word ‘cadastre’ meaning ‘register of territorial property’. These maps are drawn to show the ownership of landed property by demarcating field boundaries of agricultural land and the plan of individual houses in urban areas. The cadastral maps are prepared by the government agencies to realise revenue and taxes, along with keeping a record of ownership.
2. Topographical Maps: These maps are also prepared on a fairly large scale. The topographical maps are based on precise surveys and are prepared in the form of series of maps made by the national mapping agencies of almost all countries of the world. These maps follow uniform colours and symbols to show topographic details such as relief, drainage, agricultural land, forest, settlements, means of communication, location of schools, post offices and other services and facilities.

Q5.Is a map different from a sketch?
Answer:
A simplified map drawn freehand which fails to preserve the true scale or orientation. Map is a part of the earth’s surface on a plane surface at a reduced scale. It may also be understood that a simple network of lines and polygons without a scale shall not be called a map. It is only referred to as “the sketch”. In simple words, map has a specific scale and sketch does not have a scale. Map is drawn scientifically and sketch is drawn roughly. Sketch drawing is an art while map making is a science and science of maps is called cartography.

Q6. Write an explanatory account of types of maps.
Answer:

On the basis of scale:
1. Large-scale maps: These maps are drawn to show small areas at a relatively large-scale. For example, the topographical maps drawn at a scale of 1 : 250,000, 1 : 50,000 or 1 : 25,000 and the village maps, the zonal plans of the cities and house plans prepared on a scale of 1: 4,000,1: 2,000 and 1: 500 are large-scale maps. These are of two types:

1. Cadastral Maps
2. Topographical Maps

2. Small-scale maps: These maps are drawn to show large areas. These are of two types:

1. Wall Maps and
2. Atlas Maps

On the basis of functions, maps are of two types:

1. Physical maps: Physical maps show natural features such as relief, geology, soils, drainage, elements of weather, climate and vegetation, etc. Physical maps include relief maps, geological maps and climatic maps.
2. Cultural maps: Cultural maps show man-made features. These include a variety of maps showing population distribution and growth, sex and age, social and religious composition, literacy, levels of educational attainment, occupational structure, location of settlements, facilities and services, transportation lines and production, distribution and flow of different commodities. It includes political maps, population maps, economic maps and transportation maps.

SHORT ANSWER TYPE QUESTION:

Q1.Why are maps considered an important tool for geography?
Answer:
Geographers need maps for following purposes:

• To get information about resources, their development and planning for their utilization;
• To study changes that are taking place on the earth;
• To understand various physical factors;
• To understand the inter-relationship between physical and human resources;
• To make a comparative analysis and
• To present facts in a way that has a memorizing effect.

Q2.How is area of map measured using a planimeter?
Answer:
The area calculation is also carried out using Polar Planimeter. In this instrument, a measure is made of the movement of a rod whose locus is constrained by having one end fixed to a radial arc. The area to be measured is traced along its perimeter in a clockwise direction with an index mark, starting from one convenient point to which the index of the tracing arm must exactly return. Reading on the dial, before and after the tracing of area’s perimeter, will give a value in instrumental units. These readings are multiplied by the same constant for the particular instrument to convert into areas in square inches or centimetres.

Q3.How is direction of map measured?
Answer:
Direction is defined as an imaginary straight line on the map showing the angular position to a common base direction. The line pointing to the north is zero direction or the base direction line. A map always shows the north direction. All other directions are determined in to this relation. The north direction enables the map- user to locate different features with respect to each other. The four commonly known directions are North, South, East and West. These are also called the cardinal points. In between the cardinal points, one may have several intermediate directions.

Q4.How is distance between maps measured by geographer, planner and other resource researcher?
Answer:
The linear features shown on the maps fall into two broad categories, i. e. straight lines and erratic or zigzag lines. The measurement of straight line features like roads, railway lines and canals is simple. It can be taken directly with a pair of dividers or a scale placed on the map surface. However, distances are required, more often, along erratic paths, i.e. the coastlines, rivers and streams. The distances along all such features can be measured by placing a thread at the starting point and carrying it along the line up to the end point. The thread is then stretched and measured to determine the distance. It can also be measured by using a simple instrument called Rotameter. The wheel of the ‘rotameter’ is moved along the route to measure the distance.

Q5.Explain in detail about physical maps.
Answer:
Physical maps: Physical maps show- natural features such as relief, geology, soils, drainage, elements of weather, climate and vegetation, etc. These are of following types:

1. Relief Maps: Relief maps show general topography of an area like mountains and valleys, plains, plateaus and drainage.
2. Geological maps: Geological Maps are drawn to show geological structures, rock types, etc.
3. Climatic Maps: Climatic Maps depict climatic regions of an area. Besides, maps are also drawn to show the distribution of temperature.

Long Answer Type Questions :

Q1.Explain the essentials of map making.
Answer:
There are five essentials of map making. These are: Scale, map projection, map generalisation, map design and map construction and production.

1. Scale: All maps are reductions. The first decision that a map-maker has to take is about the scale of the map. The choice of scale is of utmost importance. The scale of a map sets limits of information contents and the degree of reality with which it can be delineated on the map.

2. Projection: Maps are a simplified representation of the three-dimensional surface of the earth on a plane sheet of paper. The transformation of all-side- curved-geoidal surface into a plane surface is another important aspect of the cartographic process. Such a radical transformation introduces some unavoidable changes in directions, distances, areas and shapes from the way they appear on a geoid. A system of transformation of the spherical surface to the plane surface is called a map projection. Hence, the choice, utilisation and construction of projections is of prime importance in map-making.

3. Generalisation: Every map is drawn with a definite objective. For example, a general purpose map is drawn to show information of a general nature such as relief, drainage, vegetation, settlements, means of transportation, etc. Similarly, a special purpose map exhibits information pertaining to one or more selected themes like population density, soil types or location of industries. It is, therefore, necessary to carefully plan the map contents while the purpose of the map must be kept in the forefront.

4. Map Design: It involves the planning of graphic characteristics of maps including the selection of appropriate symbols, their size and form, style of lettering, specifying the width of lines, selection of colours and shades, arrangement of various elements of map design within a map and design for map legend.

5. Map Construction and Production: The drawing of maps and their reproduction is the fifth major task in the cartographic process. It can be manual or computerised method.

Q2.How does a geographer measure the distance?
Answer:
The measurement of area of features like that of administrative and geographic units is also carried out over the surface of the map by map-users. There are different methods in which areas can be determined.

1. By means of regular pattern of squares: In this method, the area to be measured is covered by squares by
placing a sheet of graph paper beneath the map on an illuminated tracing table or by tracing the area onto the square sheet. The total number of ‘whole squares’ are summed up, together with ‘partial squares’. The area is then determined by a simple equation:

2. By using Polar Planimeter: In this instrument, a measure is made of the movement of a rod whose locus is constrained by having one end fixed to a radial arc. The area to be measured is traced along its perimeter in a clockwise direction with an index mark, starting from one convenient point to which the index of the tracing arm must exactly return. Reading on the dial, before and after the tracing of area’s perimeter, will give a value in instrumental units. These readings are multiplied by the same constant for the particular instrument to convert into areas in square inches or centimetres.

Q3.Explain in detail about cultural maps.
Answer:
Cultural Maps: Cultural maps show man-made features. These include a variety of maps showing population distribution and growth, sex and age, social and religious composition, literacy, levels of educational attainment, occupational structure, location of settlements, facilities and services, transportation lines and production, distribution and flow of different commodities.

• Political Maps: These maps show the administrative divisions of an area such as country, state or district. These maps facilitate the administrative machinery in planning and management of the concerned administrative unit.
• Population Maps: The population maps are drawn to show the distribution, density and growth of population, age and sex composition, distribution of religious, linguistic and social groups, occupational structure of the population, etc.
• Economic Maps: Economic maps depict production and distribution of different types of crops and minerals, location of industries and markets, routes for trade and flow of commodities.
• Transportation Maps: These maps show roads, railway lines and the location of railway stations and airports.