What is a Cartogram?

S5-SA2-0382

Grade Level:

Class 7

Law, Civic Literacy, Economics, FinTech, Geopolitics, Personal Finance, Indian Governance

Definition

What is it?

A cartogram is a special kind of map where the size of different areas (like states or countries) is changed not by their actual land area, but by a specific topic's value. So, a state with more people might look bigger on a population cartogram, even if its actual land size is small.

Simple Example

Quick Example

Imagine you have a map of India. If you wanted to show which states have the most mobile phone users, a regular map might not be clear enough. A cartogram would make states with many mobile users appear much larger, while states with fewer users would shrink, even if their actual land area is big.

Worked Example

Step-by-Step

Let's make a simple cartogram showing the number of chai stalls in three cities:

1. **Gather Data:** Suppose Mumbai has 1000 chai stalls, Delhi has 800, and Bengaluru has 600.
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2. **Decide Scale:** We need to decide how much area represents one chai stall. Let's say 100 chai stalls equals 1 unit of map area.
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3. **Calculate New Sizes:**
* Mumbai: 1000 chai stalls / 100 = 10 units of area
* Delhi: 800 chai stalls / 100 = 8 units of area
* Bengaluru: 600 chai stalls / 100 = 6 units of area
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4. **Redraw Map (Mentally):** On your cartogram, Mumbai would look the biggest, then Delhi, and Bengaluru the smallest, even if their actual city boundaries are different. This map now clearly shows the *density of chai stalls* rather than just land area.
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**Answer:** A cartogram for chai stalls would show Mumbai largest, followed by Delhi, then Bengaluru, based on their respective number of stalls.

Why It Matters

Cartograms help us quickly understand data related to population, economy, or elections, making complex information easy to see. This is useful for government officials planning development, economists studying market trends, and even journalists explaining election results to the public.

Common Mistakes

MISTAKE: Thinking a cartogram shows the actual geographic size of a place. | CORRECTION: Remember, a cartogram distorts geographic size to represent a specific dataset, not actual land area.

MISTAKE: Confusing a cartogram with a choropleth map (which uses colours to show data). | CORRECTION: Cartograms change the *size* of areas, while choropleth maps change the *colour* or shading of areas, keeping the original shape.

MISTAKE: Believing a bigger area on a cartogram always means more people. | CORRECTION: A bigger area on a cartogram means a higher value for the *specific data* being shown (it could be population, but also income, votes, etc.).

Practice Questions

Try It Yourself

QUESTION: If a cartogram shows states based on the number of votes cast in an election, which state would likely appear largest: Uttar Pradesh or Goa? | ANSWER: Uttar Pradesh, because it has a much larger population and therefore more voters than Goa.

QUESTION: A cartogram of Indian states shows Kerala appearing much larger than its actual land area, while Rajasthan appears smaller. What kind of data is this cartogram most likely representing? | ANSWER: Population density, as Kerala has a very high population density and Rajasthan has a low one.

QUESTION: You are making a cartogram of Indian states based on the number of government schools. If Maharashtra has 1,000 schools and Sikkim has 100 schools, and 1 unit of area represents 50 schools, how many units of area would each state occupy on your cartogram? | ANSWER: Maharashtra: 1000 schools / 50 = 20 units. Sikkim: 100 schools / 50 = 2 units.

MCQ

Quick Quiz

What is the main purpose of a cartogram?

To show the exact geographic boundaries of countries

To display data by distorting the size of geographic areas

To indicate elevation and physical features of a region

To compare the climate zones across different continents

The Correct Answer Is:

A cartogram's main purpose is to show data by changing the size of regions on a map, making areas with higher values for the chosen data appear larger. It does not show exact boundaries, elevation, or climate zones.

Real World Connection

In the Real World

When you see news reports about election results in India, sometimes they use cartograms to show which political party won more seats. States where a party won many seats might appear much larger on the map, making it visually clear where their strength lies, even if the state's actual land area is small. This helps understand the political landscape better.

Key Vocabulary

Key Terms

DISTORT: To twist or pull out of shape, making something look different from its actual form. | GEOGRAPHIC AREA: The actual physical space or land size of a region, like a state or city. | DATASET: A collection of related information or facts, like population numbers or election votes. | VISUALIZATION: The process of representing information in a graphical or pictorial form to make it easier to understand.

What's Next

What to Learn Next

Now that you understand cartograms, you can explore choropleth maps next. Choropleth maps also show data on maps, but they use colours and shading instead of changing the size of areas. This will help you compare different ways of visualizing geographic data!