Class 6 Geography Notes Chapter 4 (Maps) – The Earth Our Habitat

1. Introduction: Maps vs. Globes

• Globe: A true model (miniature form) of the Earth. Useful for understanding the overall shape, continents, and oceans in their correct relative sizes and locations.
  • Limitations: Difficult to carry, cannot show detailed information for small areas (like a town or district), only one part of the Earth can be seen at a time.
• Map: A representation or a drawing of the Earth's surface or a part of it, drawn on a flat surface according to a scale.
  • Advantages: Can show the entire world or specific parts (continents, countries, cities, villages), provides more detailed information than a globe, easy to carry and handle.

2. Types of Maps

Maps can be broadly classified based on the information they provide:

• Physical Maps (or Relief Maps):
  • Show natural features of the Earth.
  • Examples: Mountains, plateaus, plains, rivers, oceans, etc.
  • Focus on the physical landscape or terrain (relief).
• Political Maps:
  • Show man-made boundaries and locations.
  • Examples: Cities, towns, villages, countries, states, along with their boundaries.
  • Focus on administrative divisions.
• Thematic Maps:
  • Focus on specific information or themes.
  • Examples: Road maps, rainfall distribution maps, maps showing distribution of forests, industries, population density, temperature zones, etc.
  • The title of the map usually indicates the theme.

3. Components of Maps

There are three essential components for reading and understanding maps:

• a) Distance (Scale):
  • Scale: The ratio between the actual distance on the ground and the distance shown on the map. It's crucial because a map is a reduced representation of reality.
  • Example: If the scale is 1 cm = 10 km, it means 1 cm on the map represents 10 km on the actual ground.
  • Types of Scale:
    • Small Scale Maps: Used to show large areas like continents or countries on a small sheet of paper. They show less detail. (e.g., 1 cm = 500 km). Think: Small scale shows a large area, but the features appear small.
    • Large Scale Maps: Used to show small areas like a village or a town plan. They show greater detail. (e.g., 1 cm = 50 meters). Think: Large scale shows a small area, but the features appear large and detailed.
    • Key Point: Large scale maps provide more information than small scale maps for a specific location.
• b) Direction:
  • Most maps contain an arrow marked with the letter ‘N’ usually in the upper right corner. This arrow indicates the North direction (North line).
  • Once North is known, other directions can be easily found.
  • Cardinal Points: The four major directions:
    • North (N)
    • South (S)
    • East (E)
    • West (W)
  • Intermediate Directions: Directions between the cardinal points:
    • North-East (NE)
    • South-East (SE)
    • South-West (SW)
    • North-West (NW)
  • Compass: An instrument used to find main directions. Its magnetic needle always points towards the North-South direction. Used by sailors, pilots, surveyors, etc.
• c) Symbols (Conventional Symbols):
  • It's not possible to draw actual shapes of features like buildings, roads, bridges, trees, railway lines, etc., on a map due to limited space.
  • Maps use standard letters, shades, colours, pictures, and lines to represent these features.
  • Conventional Symbols: These are internationally agreed-upon symbols used to depict various features. They allow anyone to understand the map regardless of the local language.
  • Examples (Common Conventions):
    • Blue: Water bodies (rivers, lakes, oceans, wells, tanks)
    • Brown: Mountains, hills
    • Yellow: Plateaus
    • Green: Plains, vegetation, forests
    • Red: Buildings, roads, settlements
    • Black: Boundaries, railway lines, specific features like temples, post offices (PO), police stations (PS).
    • Specific line patterns for railway lines (broad gauge, meter gauge), roads (metalled, unmetalled), boundaries (international, state, district).

4. Sketch vs. Plan

• Sketch:
  • A drawing mainly based on memory and spot observation.
  • Not drawn to scale.
  • Rough drawing used to show the location of a place relative to other places (e.g., directions to a friend's house).
• Plan:
  • A drawing of a small area on a large scale.
  • Gives detailed information (e.g., length and breadth of a room, layout of a building).
  • Drawn accurately to scale.
  • Used by architects and engineers.

Key Takeaways for Exams:

• Understand the fundamental difference between a globe and a map and their respective uses.
• Know the definitions and examples of Physical, Political, and Thematic maps.
• Clearly understand the concept of 'Scale' and differentiate between 'Small Scale' and 'Large Scale' maps (know which shows more detail and which covers larger areas).
• Be familiar with Cardinal and Intermediate directions and the use of a compass.
• Recognize common Conventional Symbols, especially the colour conventions (blue for water, brown for mountains, etc.) and symbols for features like railway lines, roads, temples, post offices.
• Know the difference between a sketch (not to scale, rough) and a plan (large scale, detailed, accurate).

These notes cover the core concepts of Chapter 4, focusing on definitions, classifications, and components essential for objective and descriptive questions in government exams. Remember to refer back to the textbook for diagrams and specific examples of symbols.