It explains the need and significance of cartographic abstractions and generalizations in the geographical information system.

1. Information System and
Cartographic Abstraction
Indrita Saha Research Scholar
Prof Ashis Sarkar Professor of Geography, Chandernagore College, West Bengal

2. • Congestion
• Coalescence
• Conflict
• Complication
• Inconsistency and
• Imperceptibility
Map generalization is
needed for a good map
layout and design. Its
because of the
following features of
spatial distribution :
Map generalization involves the
following operations:
Simplification
Smoothing
Aggregation
Amalgamation
Merging
Collapse
Refinement
Typification
Exaggeration
Displacement and
Classification

3. OBJECTIVES
1. To establish digital database utilizing modern
technologies of Photogrammetry, RS and GIS.
2. To examine spatial features of generalization at
different levels / hierarchy of planning.
3. To examine its utility to the potential users
(decision makers) at different levels of
generalization.

4. METHODOLOGY
•Extracting and separating feature layers from large scale
maps
•Generalizing the large scale maps to smaller scales
•Compare and contrast maps at different scale/level
•Proposed suitable map scales for different level of planning

5. 1:4,000
1:5,000

6. 1:25,000
1:10,000

7. 1:100,000
1:50,000

8. Scale Symbolization Simplification Exaggeration Displacement Smoothing Elimination Aggregation
1 : 4,000
1 : 5,000 √
1 : 10,000 √
1 : 25,000 √ √ √ √
1 : 50,000 √ √ √
1 : 100,000 √ √ √ √ √ √ √
1 : 200,000 √ √ √ √ √ √ √
SCALEDEPENDANTPARAMETERSOFCARTOGRAPHICABSTRACTION
Scale Feature resolution (m)
1 : 2,500 1.25
1 : 10,000 5.00
1 : 24,000 12.00
1 : 50,000 25.00
1 : 100,000 50.00
1 : 250,000 125.00
1 : 500,000 250.00
1 : 1,000,000 500.00
1 : 10,000,000 5000.00
MAP SCALEANDEFFECTIVE CARTOGRAPHICRESOLUTION

9. Scale 1 : 4,000 1 : 5,000 1 : 10,000 1 : 25,000 1 : 5000 1 : 100,000 1 : 200,000
County √ √ √ √ √ √ √
City Body √ √ √ √ √ √ √
Main City Division √ √ √ √ √ √
Parks √ √ √ √ √ √
Major Waterbody √ √ √ √ √ √ √
Rivers √ √ √ √ √ √ √
Areas / Regions √ √ √ √ √ √
Streets √ √ √ √
Major Roads √ √ √ √ √ √
Secondary Road √ √
Primary Roads √ √ √ √ √ √ √
Railway Lines √ √ √ √
Transport Hub √ √ √
Institute √ √ √
Retail √ √ √
Reclaimed Areas √ √ √
Institute Shield 5 √ √ √
Institute Shield 515 √ √
Institute Shield 1550 √ √
05 √ √ √
515 √ √
1550 √ √
SCALEDEPENDANTRESOLUTIONSOF MAP FEATURES

10. Scale Hierarchy
Point Line Area
Feature Size Colour Feature Width Colour Feature Colour
1 : 10,000 Mouza Spot Height 5 Black Streams (perennial) 1 Blue Rural Settlement Red
Bench Mark 5 Black Streams (non pere) 1 Black Urban Settlement Magenta
School 5 Blue NH 7 Red PF Green
College 8 Blue SH 7 Pink RF Green
Post Office 8 Green MDR 5 Red Jungle Green
Police Station 8 Green PWD Road 5 Pink Plantation Green
Hospitals 8 Red Morrum / Metalled 3 Red River Blue
Medical Centres 5 Red Planning Roads 3 Pink Ponds / Tanks Blue
Temple 5 Brown Unmetalled 1 Red Agricultural Land Yellow
Mosque 5 Brown Railways 3 Black Scrub Brown
Church 5 Brown Canals 2 Blue Gullied Brown
Wells 3 Black / Blue Broken Grounds 2 Black Sandy Areas Dark Yellow
Railway Station 3 Black Embankments 2 Black Mines Grey
Industrial Area Ash
Dumping Ground Mixed
Graveyard Brown
Burning Ghat Brown
1 : 1,00,000 Gram PanchayatBench Mark 3 Black Streams (perennial) 1 Blue Rural Settlement Red
School 3 Blue Streams (non perennial) 1 Black Urban Settlement Magenta
College 5 Blue NH 7 Red PF Green
Post Office 5 Green SH 7 Pink RF Green
Police Station 5 Green MDR 5 Red Jungle Green
Hospitals 5 Red PWD Road 5 Pink Plantation Green
Medical Centres 3 Red Morrum / Metalled 3 Red River Blue
Temple 3 Brown Planning Roads 1 Pink Ponds / Tanks Blue
Mosque 3 Brown Unmetalled 1 Red Agricultural Land Yellow
Church 3 Brown Railways 3 Black Scrub Brown
Wells 2 Black / Blue Canals 2 Blue Gullied Brown
Railway Station 3 Black Broken Grounds 1 Black Sandy Areas Dark Yellow
Graveyard 3 Brown Embankments 1 Black Mines Grey
Burning Ghat 3 Brown Industrial Area Ash
Dumping Ground Mixed
Patternof SizeandColourof SpatialFeatures

11. Mouza→ GramPanchayat
1 : 10,000 1 : 1,00,000

12. Features Changes
Spot Height Eliminated
Bench Mark ↓ Size
School ↓ Size
College ↓ Size
Post Office ↓ Size
Police Station ↓ Size
Hospitals ↓ Size
Medical Centres ↓ Size
Temple ↓ Size
Mosque ↓ Size
Church ↓ Size
Wells ↓ Size
Railway Station ↓ Size
Feature Changes
Streams (perennial) No Change
Streams (non
perennial) No Change
NH No Change
SH No Change
MDR No Change
PWD Road No Change
Morrum / Metalled No Change
Planning Roads ↓ Width
Unmetalled No Change
Railways No Change
Canals No Change
Broken Grounds ↓ Width
Embankments ↓ Width
Feature Changes
Rural Settlement No Change
Urban Settlement No Change
PF No Change
RF No Change
Jungle No Change
Plantation No Change
River No Change
Ponds / Tanks No Change
Agricultural Land No Change
Scrub No Change
Gullied No Change
Sandy Areas No Change
Mines No Change
Industrial Area No Change
Dumping Ground No Change
Graveyard Converted to Point
Burning Ghat Converted to Point
Point Features Line Features Area Features
SPATIALCHANGES: Mouza→ GramPanchayat

13. Scale Hierarchy
Point Line Area
Feature Size Colour Feature Width Colour Feature Colour
1 : 1,00,000 Gram PanchayatBench Mark 3 Black Streams (perennial) 1 Blue Rural Settlement Red
School 3 Blue Streams (non pere) 1 Black Urban Settlement Magenta
College 5 Blue NH 7 Red PF Green
Post Office 5 Green SH 7 Pink RF Green
Police Station 5 Green MDR 5 Red Jungle Green
Hospitals 5 Red PWD Road 5 Pink Plantation Green
Medical Centres 3 Red Morrum / Metalled 3 Red River Blue
Temple 3 Brown Planning Roads 1 Pink Ponds / Tanks Blue
Mosque 3 Brown Unmetalled 1 Red Agricultural Land Yellow
Church 3 Brown Railways 3 Black Scrub Brown
Wells 2 Black / Blue Canals 2 Blue Gullied Brown
Railway Station 3 Black Broken Grounds 1 Black Sandy Areas Dark Yellow
Graveyard 3 Brown Embankments 1 Black Mines Grey
Burning Ghat 3 Brown Industrial Area Ash
Dumping Ground Mixed
1 : 2,00,000 C.D. Block Bench Mark 3 Black Streams (perennial) 1 Blue Settlement Red
School 2 Blue NH 5 Red Forest Green
College 3 Blue SH 5 Pink Plantation Green
Post Office 3 Green MDR 3 Red River Blue
Police Station 3 Green PWD Road 3 Pink Ponds / Tanks Blue
Hospitals 3 Red Morrum / Metalled 2 Red Agricultural Land Yellow
Medical Centres 2 Red Planning Roads 1 Pink Scrub Brown
Temple 2 Brown Railways 2 Black Gullied Brown
Mosque 2 Brown Canals 2 Blue Sandy Areas Dark Yellow
Church 2 Brown Industrial Area Ash
Railway Station 3 Black Dumping Ground Mixed
Graveyard 3 Brown
Burning Ghat 3 Brown
Mines 2 Black
Patternof SizeandColourof SpatialFeatures

14. 1 : 1,00,000 1 : 2,00,000
GramPanchayat → CD Block

15. Feature Size
Bench Mark ↓ Size
School ↓ Size
College ↓ Size
Post Office ↓ Size
Police Station ↓ Size
Hospitals ↓ Size
Medical Centres ↓ Size
Temple ↓ Size
Mosque ↓ Size
Church ↓ Size
Wells ↓ Size
Railway Station ↓ Size
Graveyard ↓ Size
Burning Ghat ↓ Size
Feature Size
Streams (perennial) ↓ Size
Streams (non perennial) Eliminated
NH ↓ Size
SH ↓ Size
MDR ↓ Size
PWD Road ↓ Size
Morrum / Metalled ↓ Size
Planning Roads No Change
Unmetalled Eliminated
Railways ↓ Size
Canals ↓ Size
Broken Grounds Eliminated
Embankments Eliminated
Feature Size
Rural Settlement Aggregation
Urban Settlement Aggregation
PF Aggregation
RF Aggregation
Jungle Aggregation
Plantation No Change
River No Change
Ponds / Tanks No Change
Agricultural Land No Change
Scrub No Change
Gullied No Change
Sandy Areas No Change
Mines Converted to point
Industrial Area No Change
Dumping Ground No Change
Point Features Line Features Area Features
SPATIALCHANGES: GramPanchayat→ CD Block

16. Scale Hierarchy
Point Line Area
Feature Size Colour Feature Width Colour Feature Colour
1 : 2,00,000 C.D. Block Bench Mark 3 Black
Streams
(perennial) 1 Blue Settlement Red
School 2 Blue NH 5 Red Forest Green
College 3 Blue SH 5 Pink Plantation Green
Post Office 3 Green MDR 3 Red River Blue
Police Station 3 Green PWD Road 3 Pink Ponds / Tanks Blue
Hospitals 3 Red Morrum / Metalled 2 Red Agricultural Land Yellow
Medical Centres 2 Red Planning Roads 1 Pink Scrub Brown
Temple 2 Brown Railways 2 Black Gullied Brown
Mosque 2 Brown Canals 2 Blue Sandy Areas Dark Yellow
Church 2 Brown Industrial Area Ash
Railway Station 3 Black Dumping Ground Mixed
Graveyard 3 Brown
Burning Ghat 3 Brown
Mines 2 Black
1 : 10,00,000 District College 3 Blue NH 3 Red Settlement Red
Police Station 3 Green SH 3 Pink Forest Green
Ponds / Tanks 2 Blue MDR 1 Red Cultivated Land Yellow
Railway Station 3 Black PWD Road 1 Pink Wasteland Brown
Mines 2 Black Railways 2 Black Industrial Area Ash
District HQ 5 Red Canals 1 Blue
Census Town 3 Red River 2 Blue
Patternof SizeandColourof SpatialFeatures

17. Feature Size
Bench Mark Eliminated
School Eliminated
College No Change
Post Office Eliminated
Police Station No Change
Hospitals Eliminated
Medical Centres Eliminated
Temple Eliminated
Mosque Eliminated
Church Eliminated
Railway Station No Change
Graveyard Eliminated
Burning Ghat Eliminated
Mines No Change
District HQ Introduced
Census Town Introduced
Feature Width
Streams (perennial) Eliminated
NH ↓ Size
SH ↓ Size
MDR ↓ Size
PWD Road ↓ Size
Morrum / Metalled Eliminated
Planning Roads Eliminated
Railways No Change
Canals ↓ Size
Feature Colour
Settlement No Change
Forest Aggregated
Plantation Aggregated
River Converted to Line
Ponds / Tanks Converted to Point
Agricultural Land No Change
Scrub Aggregated
Gullied Aggregated
Sandy Areas Aggregated
Industrial Area Aggregated
Dumping Ground Aggregated
Point Features Line Features Area Features
SPATIALCHANGES: CDBlock→ District

18. Scale Hierarchy
Point Line Area
Feature Size Colour Feature Width Colour Feature Colour
1 : 10,00,000 District College 3 Blue NH 3 Red Settlement Red
Police Station 3 Green SH 3 Pink Forest Green
Ponds / Tanks 2 Blue MDR 1 Red Cultivated Land Yellow
Railway Station 3 Black PWD Road 1 Pink Wasteland Brown
Mines 2 Black Railways 2 Black Industrial Area Ash
District HQ 5 Red Canals 1 Blue
Census Town 3 Red River 2 Blue
1 : 50,00,000 State District HQ 4 Red NH 2 Red Forest Green
Capital 6 Red SH 2 Pink Cultivated Land Yellow
Cities 2 Red Railways 2 Black Wasteland Brown
Airport 3 Blue River 2 Blue Industrial Area Ash
1 : 2,00,00,000 Country State Capital 5 Red NH 2 Red Physiographic Divisions
Airport 3 Blue
Major
Railways 2 Black Soil Regions
Million Cities 3 Red Rivers 1 Blue Climatic Regions
Natural Vegetation Regions
Patternof SizeandColourof SpatialFeatures

19. 1 : 10,00,000 1 : 50,00,000 1 : 2,00,00,000

20. Point Features Line Features Area Features
SPATIALCHANGES: District→ State
Feature Changes
College Eliminated
Police Station Eliminated
Ponds / Tanks Eliminated
Railway Station Eliminated
Mines Eliminated
District HQ ↓ Size
Census Town Eliminated
Capital Introduced
Cities Introduced
Airport Introduced
Feature Changes
NH ↓ Size
SH ↓ Size
MDR Eliminated
PWD Road Eliminated
Railways No Change
Canals Eliminated
River No Change
Feature Changes
Settlement Eliminated
Forest Green
Cultivated Land Yellow
Wasteland Brown
Industrial Area Ash

21. Generalization and
Planning

22. Planning Units Scale
Feature Resolution
after Generalization
(m)
Remarks
Gram Panchayat 1 : 5,000 to 1 : 10,000 2.5 – 5.0 Resolution ↓
Generalization ↑
Spatial Order / Regularity ↑
CD Block 1 : 100,000 to 1: 200,000 50.0 – 100.0
District
1 : 500,000 to 1 :
1,000,000
250.0 – 500.0
For India,
• Point Feature → Symbol
No size constraint
Exact Location
Lost Dimension
• Line Feature → Symbol
Distance preserved
Direction preserved
Compromised Width
• Area Feature → Colour / Shade Coded
Maintains Shape
Preserves Area
The level of detail and importance of what
is remaining on the map must outweigh
the insignificance of items that were
generalized, as to preserve the
distinguishing characteristics of what
makes the map useful and important
against the constraint of limited map
space.

23. Creating Database for each feature
separately in different layers at the lowest
hierarchical level.
Generalization of map features from the
base map at lower scales.
Extraction and Superimposition of
feature layers as required by the user.
Identifying patterns and analysis of
inter-relationships among variables.
PLANNING

24. Regional Development & Planning
Spatial Data Models (SDM: Map)
SDM = ∫ (Theme, Scale, Level)
Thrust
Area
Spatial
Resolutio
n
Generalization

25. Contact:
indrita.saha@gmail.com
profdrashis@gmail.com

26. Need / Function
Scale
Minimum Maximum
Planning: Master Plan/ Structure Plan, Zoning Plan 1:5000 1:4000
Engineering Plans 1:4000 1:2000
Housing Plans 1:4000 1:1000
Water Supply, Sewerage 1:2000 1:1000
Traffic Junction Plans 1:2000 1:1000
Transportation Routes 1:10000 1:5000
Roads & Highways 1:10000 1:2000
Revenue Authorities 1:4000 1:1000
Unauthorised construction, encroachment, squatter settlement, etc 1:4000 1:2000
Ground Water 1:25000 1:10000
Drainage 1:25000 1:10000
Inventory of trees, parks, environmental themes 1:10000 1:4000
Heritage Monuments 1:1000
Police Station / Fire Brigade 1:2000