Cartography and Geo-Spatial Techniques

The science and art of map-making and spatial data representation.

Author

Geography Team

Official Syllabus

NEP-2020 Syllabus

NoteCore I Paper IV — Cartography and Geo-Spatial Techniques

**(4 Credit, Theory: 45hrs, Practical: 30hrs)*

**Unit I:* - Scientific basis of Cartography, needs of map making, characteristics of maps - Geographical Coordinates (Latitude and Longitude), Graticules - Types of Scales (Plain, and Diagonal Scale)

**Unit II:* - Meaning, Uses and types of Map Projection - Transformation of area, Distance and Direction, Choice of map projection - Interpretation of Bedding plane, Strike, Dip, structure & stratigraphy of Geological map - Methods of determination of slope (Wentworth’s method and Smith)

**Unit III:* - History of Geographical Information System, Components of GIS - Dimensions of GIS data (field/object) and logical (raster/vector) - Data sources, data types (raster/vector/attribute) - History of Remote Sensing, Types of Platform, Sensor characteristics - Aerial photographs and Visual interpretation of Satellite images - Global Positioning System (GPS) and Global Navigation Satellite System (GNSS) - Applications of GIS and RS

UGC NET Syllabus

TipUnit X — Cartography
  • Types of Maps, Techniques of Map Making
  • Data Representation on Maps
  • Thematic maps: Choropleth, Isarithmic, Dasymetric, Chorochromatic, Flow Maps

NET Cartography — Detailed Syllabus (Pulakesh Pradhan)

ImportantSyllabus Topics (50 marks section — 10 Marks)
  • Map as a tool in Geographical Studies
  • Types of maps
  • Techniques for the study of spatial patterns of distribution
  • Single purpose and composite purpose maps
  • Choropleth, Isopleth and chorochromatic map
  • Pie diagram
  • Mapping of location specific data
  • Accessibility and flow maps

Important Topics for NET

TipHigh-Yield Topics
  • Thematic Map, R.F of Map
  • Scales of Map — Small, Medium, Large
  • Map Enlargement / Reduction
  • Flow Map, Choropleth Map, Choroschematic Map, Chorochromatic Map
  • Star Diagram, Scatter Diagram, Bar Diagram
  • Hythergraph, Triangular Diagram
  • Toposheet (SOI interval), Dot Map (Multiple), Sphere Diagram
  • Contours, Hachures
  • Isobars, Isochrones, Isobaths, Isogonic, Isopaches, Isoneph, Isopleth

Welcome to the Cartography and Geo-Spatial Techniques module of Geography OpenCourseWare.

Part A: Common Topics (NEP-2020 & UGC NET)

These topics are covered in both the NEP-2020 undergraduate syllabus and the UGC NET syllabus.

Basics of Cartography and Scale

Warning📘 Syllabus Coverage
Syllabus Topic Details
NEP-2020 Unit I — Needs, characteristics of maps, Coordinates, Scales
UGC NET Types of Maps, Techniques of Map Making

Get the Presentation ↗   |   Watch the Video ↗

NoteKey Concepts
  • Cartography: Science and art of making maps. Evolution from manual drafting to digital cartography.
  • Geographical Coordinates: Latitude (parallels) and Longitude (meridians) forming a graticule to pinpoint absolute locations.
  • Map Scale: The ratio between distance on the map and corresponding distance on the ground.
    • Representative Fraction (RF): 1:50,000. Independent of units.
    • Graphical/Linear Scale: A drawn line divided into segments. Remains true even if the map is enlarged/reduced.
    • Statement Scale: “1 cm represents 1 km”.
  • Nautical Mile: One nautical mile measures the arc-length distance along the great-circle against 1’ (one minute) of angular distance at the centre of the Earth.

Types of Maps — Detailed (NET Notes — Pulakesh Pradhan)

Topographic Maps

  • Include contour lines to show shape and elevation of an area
  • Lines close together show steep terrain; lines far apart show flat terrain
  • Used by geologists to record rock types and engineers for planning

Thematic Maps

  • Represent climate, precipitation, vegetation, elevation, population, life expectancy, etc.
  • Usually used when looking at a single piece of information
NoteTypes of Thematic Maps
  • Choropleth map — regions colored, shaded, or patterned in relation to value
  • Heat map — color represents intensity without geographical boundaries
  • Proportional symbol map — symbols scaled by value (circles or pies)
  • Dot density map — dots represent a feature or attribute
  • Animated time series map — data with temporal context

Physical Map

  • Shows natural features: mountains, plateaus, plains, rivers, oceans
  • Also called relief maps; do not contain man-made features
  • Green at lower elevations, orange/brown at higher elevations

Political Map

  • Shows cities, towns, villages, countries, states with boundaries
  • Does not show physical features
  • Capital cities marked with a star within a circle

Scales — Detailed (NET Notes)

Scale Type Description
Verbal Scale Expresses in words: “one inch represents 16 miles”
Graphic Scale / Bar Scale Shows directly on the map the corresponding ground distance
Representative Fraction (RF) Most abstract and versatile; e.g., 1:25000

Scale Size Classification

  • Large scale: 1:25,000 or larger
  • Medium scale: 1:1,000,000 to 1:25,000
  • Small scale: 1:1,000,000 or smaller

Map Enlargement and Reduction

  • If RF is 1:5000 and map is reduced three times, new RF becomes **1:15,000*

Map Projections

Warning📘 Syllabus Coverage
Syllabus Topic Details
NEP-2020 Unit II — Meaning, Uses, types, Choice of projection
UGC NET Techniques of Map Making

Get the Presentation ↗   |   Watch the Video ↗

NoteKey Concepts
  • Map Projection: Mathematical method of transferring the graticule of a sphere onto a flat surface.
  • Types by Developable Surface:
    • Cylindrical: Best for equatorial regions (e.g., Mercator).
    • Conical: Best for mid-latitudes.
    • Zenithal/Azimuthal: Best for polar regions.
  • Types by Property Preserved:
    • Orthomorphic/Conformal: Preserves shape/local angles. Examples include Stereographic and Mercator projections.
    • Homolographic/Equal Area: Preserves area (crucial for thematic mapping like population density).
    • Equidistant: Preserves scale along certain lines.
  • Choice: Depends on purpose (navigation vs. statistical display) and Latitudinal extent of the mapped area.

Topographical and Geological Maps

Warning📘 Syllabus Coverage
Syllabus Topic Details
NEP-2020 Unit II — Interpretation of Bedding plane, Strike, Dip, structure
UGC NET Types of Maps

Get the Presentation ↗   |   Watch the Video ↗

NoteKey Concepts
  • Topographical Maps: Detailed, accurate graphic representation of features that appear on the Earth’s surface (relief, drainage, settlements, roads). Produced by Survey of India (SoI).
  • Geological Maps: Show the distribution of different rock types or geologic strata exposed at the surface.
    • Strike: The direction of the line formed by the intersection of a rock surface with a horizontal plane.
    • Dip: The acute angle that a rock surface makes with a horizontal plane (magnitude and direction).
  • Slope Analysis: Techniques like Wentworth’s or Smith’s method to derive quantitative slope data from contour lines on topomaps.

Toposheet — Detailed (NET Notes — Pulakesh Pradhan)

Major Elements Shown

  • Cultural: roads, buildings, urban development, railways, states, international borders
  • Hydrography: lakes, rivers, streams, swamps, coastal flats
  • Relief: mountains, valleys, contours, cliffs, depressions
  • Vegetation: wooded and cleared areas, vineyards, orchards

Contour

  • Joins points of equal elevation
  • The vertical distance between two consecutive contours is called the **contour interval*

Survey of India (SOI) — Detailed (NET Notes)

  • Prints maps at 1:250,000, 1:50,000, and **1:2,500*
  • Based on Everest datum and **Polyconic Projection*
Map Series Datum Projection
OSM (Open Series Map) WGS-84 UTM
DSM (Defence Series Map) WGS-84 LLC
  • OSM = publicly available
  • DSM = supports national security

General Wall Maps and State Maps

  • General wall maps: 1:12M scale
  • State maps: 1:1M scale

Dot Maps (NET Notes)

  • A dot represents features or phenomena
  • Dot maps rely on visual scatter to show spatial pattern
  • One-to-one: each dot represents a single recorded phenomenon
  • One-to-many: each dot may represent more than one phenomenon

Introduction to GIS and Remote Sensing

Warning📘 Syllabus Coverage
Syllabus Topic Details
NEP-2020 Unit III — GIS components, data types, RS platforms, GPS
UGC NET Geographic Information System (GIS), Remote Sensing

Get the Presentation ↗   |   Watch the Video ↗

NoteKey Concepts
  • GIS Components: Hardware, Software, Data, People, Methods.
  • Data Models: Vector (points, lines, polygons for discrete objects) and Raster (grid cells for continuous fields like elevation).
  • Remote Sensing: Acquiring information from a distance. Types of platforms (ground, aerial, space-borne) and sensor characteristics (spatial, spectral, temporal, radiometric resolution).
  • GNSS/GPS: Global Navigation Satellite System providing autonomous geo-spatial positioning. Uses triangulation from a constellation of satellites. Segments: Space, Control, and User.

Quick Reference

Key Scholars — Cartography

Contributors and Their Contributions (NET Notes — Pulakesh Pradhan)

Scholar Key Contribution
Gerardus Mercator Developed the Mercator projection (1569); revolutionised marine navigation
Claudius Ptolemy Geographia; early map projections and coordinate systems
Arthur H. Robinson Developed the Robinson projection (1963) for visually appealing world maps
Eratosthenes Early calculations of the Earth’s circumference and tilt
Arno Peters Gall-Peters projection; equal-area map highlighting the true size of developing nations

Notes compiled by Pulakesh Pradhan — Cartography (NET)

Cartography Quick Reference

Key Books and Authors

Book Author
Elements of Cartography Arthur H. Robinson
Semiology of Graphics Jacques Bertin
How to Lie with Maps Mark Monmonier
Maps and Diagrams Monkhouse & Wilkinson

Key Map Projections

Projection Property / Use Case
Mercator Projection Cylindrical Conformal; straight rhumb lines; used for navigation. Distorts size near poles.
Gall-Peters Projection Cylindrical Equal-Area; preserves area, distorts shape. Used for thematic mapping.
Robinson Projection Compromise projection; neither equal-area nor conformal; visually pleasing for world maps.
Gnomonic Projection Azimuthal; all great circles are straight lines; used for plotting shortest routes.

Thematic Mapping Techniques

Technique Description
Choropleth Uses color or shading to represent data values for predefined regions (e.g., population density).
Isopleth Uses lines (isolines) to connect points of equal continuous value (e.g., isotherms, contours).
Dot Map Uses dots to represent the spatial distribution and density of a discrete phenomenon.
Cartogram Scales areas based on data values (e.g., population size) rather than geographic area.

Notes compiled by Geography Team