Cartograms – Map-Based Representation of Data 🗺️📊

Cartograms combine statistics with geography.
They represent data on a map, making regional comparisons easy.

Used widely in:

• Census reports
• Election analysis
• GDP by state
• Crop production maps

What Is a Cartogram?

Definition:

A cartogram is a map-based diagram where statistical data (population, literacy, rainfall, production) is shown geographically.

Cartograms add meaning to maps by integrating numbers.

Types of Cartograms 🧩

1. Dot Cartogram

Uses dots to show frequency.

Example: 1 dot = 10,000 people → map of India showing population clusters.

Used for:

• Population
• Disease incidence
• Urbanization

2. Choropleth Map (Shaded Cartogram)

Regions are shaded according to value.

Example: Dark shade = high literacy
Light shade = low literacy

Used for:

• Literacy
• Rainfall
• Poverty levels

3. Proportional Symbol Map

Symbols (circles/squares) represent magnitude.

Example: Circle size ∝ city population.

ASCII Diagram — Types of Cartograms

Dots
↓
Shaded Regions
↓
Proportional Symbols

Advantages ✔️

• Shows geographical distribution
• Helps compare regions easily
• Very effective for reports and presentations
• Combines statistical + spatial information

Limitations ❌

• Requires map drawing skills
• Not precise enough for small differences
• Interpretation depends on scale & shading
• Can be misleading if symbols are too large

Summary ✨

Cartograms display data in a geographic context using:

• Dots
• Shading
• Proportional symbols

They help understand regional patterns in statistics.

Quiz Time! 🎯