Cartographic Skills » Atlas and Base Maps

What you'll learn this session

Study time: 30 minutes

How to read and interpret atlas maps
Understanding base maps and their features
How to use grid references, scale and direction on maps
Identifying map symbols and understanding map keys
Practical applications of cartographic skills in geography

Introduction to Cartographic Skills: Atlas and Base Maps

Maps are the geographer's most essential tool! They help us understand our world by showing the relationships between places, physical features and human activities. In this session, we'll explore how to use atlas and base maps effectively, which is a crucial skill for your iGCSE Geography exams and beyond.

Key Definitions:

Cartography: The art and science of making maps.
Atlas: A collection of maps, typically in book form.
Base map: A simple map showing fundamental features like coastlines, borders and major cities, which can be used to add other information.
Topographic map: A detailed map showing physical features like hills, valleys and rivers using contour lines.

🗺 Atlas Maps

Atlas maps are collections of maps showing different aspects of our world. They typically include:

Political maps (showing countries and borders)
Physical maps (showing landforms and water bodies)
Thematic maps (showing specific data like population or climate)
Regional maps (focusing on particular areas)

Atlases often include an index to help you locate specific places quickly!

📍 Base Maps

Base maps provide the foundation for geographic analysis. They show:

Coastlines and water bodies
Political boundaries
Major settlements
Key physical features

Geographers add specific data to base maps to create thematic maps that show patterns and relationships.

Essential Map Components

All good maps, whether in an atlas or a base map, should include these key elements:

📏 Title

Tells you what the map is showing. Always check this first to understand the map's purpose!

📏 Scale

Shows the relationship between distance on the map and real-world distance. Can be shown as a ratio (1:50,000), a statement (1cm = 0.5km), or a scale bar.

📏 Key/Legend

Explains what the symbols, colours and patterns on the map represent. Always refer to this when interpreting map features!

📏 Direction

Usually shown with a north arrow. Most maps are oriented with north at the top, but always check!

📏 Grid References

Help you locate and describe specific positions on a map using coordinates.

📏 Date

Shows when the map was created or updated. Important for understanding if information might be outdated.

Understanding Grid References

Grid references are a system for precisely locating places on a map. They're essential for your iGCSE exams and fieldwork!

📌 Four-Figure Grid References

These identify a 1km square on a map. Remember the saying: "Along the corridor, then up the stairs."

Find the bottom-left corner of the square containing your location
Read the eastings value (horizontal axis) first
Then read the northings value (vertical axis)
Example: The town is at grid reference 2347

📌 Six-Figure Grid References

These provide more precise locations within a grid square, down to 100m accuracy.

Find the four-figure grid reference first
Estimate tenths along the square eastwards (3rd digit)
Estimate tenths up the square northwards (6th digit)
Example: The church is at grid reference 236472

Map Scale and Distance

Scale tells us how much the real world has been shrunk to fit on the map. Understanding scale helps you measure distances and understand the area a map covers.

📏 Types of Scale

Representative Fraction (RF): Written as a ratio, e.g., 1:50,000 (1cm on map = 50,000cm or 500m in real life)
Statement Scale: Written as a sentence, e.g., "1cm represents 0.5km"
Linear Scale: A line marked with distances, allowing direct measurement with a ruler

📏 Calculating Real Distances

To find the real-world distance:

Measure the distance on the map in centimetres
Multiply by the scale number (if 1:50,000, multiply by 50,000)
Convert to appropriate units (usually km)

Example: 4cm on a 1:50,000 map = 4 × 50,000 = 200,000cm = 2km

Map Symbols and Keys

Maps use symbols to represent features that would be too detailed to draw realistically at scale. Learning common map symbols will help you read maps quickly and accurately.

🔬 Common OS Map Symbols

Blue features: Water bodies (rivers, lakes, seas)
Green areas: Vegetation (forests, parks, golf courses)
Brown lines: Contour lines showing elevation
Black symbols: Human-made features (buildings, bridges)
Red lines: Major roads and boundaries

Always check the map key for the specific meaning of symbols on that particular map!

🔬 Interpreting Thematic Maps

Thematic maps show specific data using:

Choropleth: Areas shaded according to data values (darker = higher values)
Proportional symbols: Symbols sized according to data values
Isoline maps: Lines connecting points of equal value (like contour lines)
Dot density maps: Dots represent quantities of something

Case Study Focus: Using OS Maps for Fieldwork

A group of GCSE students investigated land use in the Lake District National Park. They used Ordnance Survey maps to:

Plan their route using grid references and scale
Identify different land uses (tourism, farming, conservation) using map symbols
Record the locations of their field observations using six-figure grid references
Calculate the area of different land uses using the map scale

Their findings showed that tourism infrastructure was concentrated in valleys and near lakes, while farming dominated the lower slopes and conservation areas were found on higher ground.

Practical Map Skills

🛠 Finding Direction

Maps typically have north at the top, but always check the north arrow to be sure. You can describe directions as:

Cardinal directions: North, South, East, West
Intermediate directions: Northeast, Southwest, etc.
Bearings: Measured in degrees clockwise from north (e.g., 090° = east)

🛠 Describing Locations

When describing locations in your exam, use:

Grid references (four or six-figure)
Relative locations (e.g., "2km south of the town")
Named features (e.g., "at the confluence of two rivers")
Compass directions from known points

Exam Tips for Cartographic Skills

In your iGCSE Geography exam, you'll need to demonstrate your ability to use atlas and base maps effectively. Here are some tips:

Practice using four and six-figure grid references until they become second nature
Learn to quickly identify common map symbols without needing to check the key
Be comfortable calculating distances using different types of scale
Practice describing locations using appropriate geographical terminology
When answering questions about maps, always refer to specific evidence from the map (grid references, named features, patterns)
Remember that atlas skills questions often require you to compare information from different maps

Digital Mapping Tools

While traditional map skills remain essential, modern geographers also use digital tools:

GIS (Geographic Information Systems): Software that allows layers of data to be displayed and analysed on digital maps
GPS (Global Positioning System): Satellite-based navigation system that provides precise location data
Google Earth/Maps: Accessible tools that combine satellite imagery with map data
Online atlases: Digital collections of maps with search and zoom capabilities

These tools build on the same fundamental cartographic principles you're learning now!

🧠 Test Your Knowledge!