Here is a comprehensive guide to Chapter 5, “Map Reading and Geographical Data Presentation,” from the “Swadesh Adhyayan” textbook, created specifically for AHSEC Class 12 students. This guide includes a summary, complete textual answers, previous years’ AHSEC questions, and other important questions.
Map Reading and Geographical Data Presentation
Here is a comprehensive guide to Chapter 5 from the “Swadesh Adhyayan” textbook, created to help you prepare thoroughly for your upcoming AHSEC Class 12 exams. This guide includes a summary, complete textual answers, previous years’ AHSEC questions, and other important questions.
Summary Note
This chapter introduces the fundamental concepts of map reading and the presentation of geographical data, which are essential tools for a geographer. A map is defined as a symbolic, scaled-down representation of the Earth’s surface (or a part of it) on a flat plane. The chapter outlines the key elements of a map, including title, location, direction, scale, and conventional legends or symbols.
A crucial concept discussed is Scale, which denotes the relationship between a distance on the map and the corresponding distance on the ground. The three types of scales are:
- Graphical or Linear Scale: A ruler printed on the map to convert map distances to ground distances.
- Statement Scale: A written statement, e.g., “1 inch represents 4 miles.”
- Representative Fraction (R.F.): A ratio or fraction (e.g., 1:100,000) where one unit on the map represents 100,000 of the same units on the ground.
The chapter also explains different types of maps, primarily Reference Maps (showing general geographic information like cities and roads) and Thematic Maps (displaying the distribution of a specific topic or theme, like population density).
Map Projections are introduced as the systematic transformation of the spherical Earth onto a flat map. Since this process always involves distortion, different projections are used for different purposes. The three basic types are:
- Cylindrical Projection: Made by wrapping a cylinder around a globe. It is best for equatorial regions (e.g., Mercator’s projection).
- Conical Projection: Made by placing a cone over a globe. It is best for mid-latitude zones.
- Zenithal (or Azimuthal) Projection: Made by projecting the globe onto a flat plane. It is often used for polar regions.
Finally, the chapter touches upon modern technologies like Remote Sensing (acquiring information from a distance using satellites or aircraft) and Geographic Information System (GIS) (a computer system to capture, store, analyze, and present geographical data). These technologies have revolutionized map-making and geographical analysis.
Complete Textual Question and Answer
1. Give the answers of the following in a word.
(i) _____ is the main tool of Geography.
Answer: Map
(ii) A map can be drawn with the help of _____.
Answer: Projection (or Scale/Grids)
(iii) _____ calculated the size of the Earth for the first time.
Answer: Eratosthenes
(iv) In 1154, during the Islamic Golden era the famous cartographer _____ prepared the best Map.
Answer: Al Idrisi
(v) Latitude and Longitude intersects to form a _____.
Answer: Grid
(vi) _____ is a simple system of surveying a field.
Answer: Chain surveying
2. Write short answers of the following questions :
(i) What is a ‘Scale’? How many types are there?
Answer: A scale denotes the relationship between the distance between any two points on a map and the corresponding distance on the ground. There are three main types of scales: Graphical or Linear Scale, Statement Scale, and Representative Fraction (R.F.).
(ii) Convert the statement into R.F. 2 miles = 63360.
(There seems to be a typo in the question. Assuming it means “1 inch = 2 miles” and “1 mile = 63360 inches”)
Answer:
1 mile = 63360 inches
Therefore, 2 miles = 2 × 63360 inches = 126,720 inches.
The statement is 1 inch = 126,720 inches.
So, the R.F. is 1:126,720.
(iii) How can you differentiate Graphical Scale and Diagonal Scale?
Answer: A Graphical (or Linear) Scale can show only primary and secondary divisions of a unit. A Diagonal Scale is an advanced form that allows for greater accuracy by further subdividing the secondary divisions into tertiary divisions, making it possible to measure smaller fractions of the unit.
(iv) What is “Remote Sensing”?
Answer: “Remote sensing” is the science of acquiring information about an object or phenomenon without making physical contact with it. It generally refers to the use of satellite or aircraft-based sensor technologies to detect and classify objects on Earth by collecting images and data.
(v) How many elements are there in a “Map”?
Answer: The text mentions several essential elements of a map, including: Title, Location, Configuration and Direction, Scale, Shape and Sizes, Distances, Area, Conventional Legends, and Time of a Map. So, there are at least nine elements.
(vi) Write about different types of “Map”?
Answer: Maps can be divided into two broad categories:
- Reference or Representative Maps: These show general geographic information about an area, including the locations of cities, boundaries, roads, mountains, and rivers. Topographic maps are a common example.
- Thematic Maps: These maps display the distribution or pattern of a specific theme or topic over the Earth’s surface, such as population density, average income, or rainfall patterns.
(vii) What is “surveying”?
Answer: Surveying is the systematic process, technique, and science of making measurements on the field to determine the relative positions of points on the Earth’s surface. The data collected from surveying is then used to draw maps and record land features.
3. Give brief answer of the following questions :
(i) What is a Projection? How many types do you find in your text book?
Answer: A map projection is a systematic transformation of the latitudes and longitudes from the curved surface of the Earth (a sphere) into locations on a flat plane (a map). The textbook mentions three basic types of projections: Cylindrical Projection, Conical Projection, and Zenithal Projection.
(ii) Name the activities, that can be acquired from ‘GIS’ software?
Answer: GIS (Geographic Information System) software allows users to perform several activities, including: creating interactive queries, analyzing spatial information, editing data in maps, and presenting the results of these operations in the form of maps, charts, graphs, and reports.
(iii) Write a short note on “Remote Sensing”.
Answer: Remote sensing is the technology of obtaining information about the Earth’s surface from a distance, typically from satellites or aircraft. Special cameras and sensors collect images and data that help researchers “sense” things about the Earth without being physically present. It is used for various purposes, such as mapping large forest fires, tracking clouds to predict weather, watching for volcanic eruptions, and mapping the ocean floor.
4. Give a description of the following.
(i) Write a note on the history of “Map”.
Answer: The history of map-making is ancient. The earliest maps were likely sketches made in the ground. One of the world’s oldest known maps, found on a stone tablet in Spain, dates back nearly 14,000 years. Ancient Sumerians produced maps with directions around 2500 BC. The Greek scholar Eratosthenes calculated the Earth’s size in the 3rd century BC, and Ptolemy advanced map-making to a new level of precision in the 2nd century AD. During the Middle Ages in Europe, maps were often religious, like the ‘T in O’ maps with Jerusalem at the center. During this time, Arab scholars preserved and advanced scientific cartography. The 19th century saw improvements with lithography, and today, modern technologies like GIS and GPS have made map-making highly accurate and instantly accessible.
(ii) What is a “chain surveying” and what kind of equipments are needed?
Answer: Chain surveying is a simple method of surveying suitable for small, flat areas with few details. In this method, only linear measurements are taken in the field using a chain or tape, and the rest of the work, like plotting and calculations, is done in the office. The main equipment needed are a chain (like an Engineer’s chain or Gunter’s chain) or a measuring tape, and arrows (steel wires used for marking the endOf course. Here is a comprehensive guide to Chapter 5, “Map Reading and Geographical Data Presentation,” from the “Swadesh Adhyayan” textbook, created specifically for AHSEC Class 12 students. This guide includes a summary, complete textual answers, previous years’ AHSEC questions, and other important questions.
