Type of maps
Maps for different purposes
Full topographic maps at different scales are required by Urban Development Authorities for preparation/ revision of Comprehensive Development Plans, Zonal Plans (Sectoral Plans), Neighbourhood Plans, Sub-division Plans, Town Planning Schemes, etc. in the local planning area. The standard scales, for town surveys and planning from city level down to detail town planning schemes in old areas, set in the Bureau of Indian Standards’s IS:963 - “Code of Practice for Architectural and Building Drawings” are: 1:20,000, 1:10,000, 1:5,000, 1:2,000, 1:1,000 and 1:500. The scale of maps required for various purposes at different stages and for different coverage are shown in Table 2.
Table 2 : Map Scales and Coverage
| Sl. No. |
For Presentation of |
Scale of map |
| |
|
1:20,000 |
1:10,000 |
1:5,000 |
1:2,000 |
1:1,000 |
1:500 |
| 1. |
City / town |
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| 2. |
Part of city |
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| 3. |
Sector (district) |
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| 4. |
Part of sector |
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| 5. |
Neighborhood |
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| 6. |
Sub-division |
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| 7. |
Cluster |
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| 8. |
Old parts / EWS housing schemes |
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The scale of map to be used for a particular purpose in a project is determined as to what topographical features and what plan elements (details) are required to be shown with a certain degree of clarity on one or more sheets. Thus, to show a concept for circulation system and layout of plots in a sub-division plan (layout), in any urban area, a 1:2,000 scale map may be adequate. But, if details on plot numbers, entrance to plots, plot dimensions, centre line of roads, chamfers, asphalt, alignment of services like water, electricity and telephone, planting of trees, etc. are to be shown, maps at scale 1:1,000 would be needed. If the width of plot and roads is less than 10 m then a 1:500 scale map would be required to show all the afore cited details. A feature/element of specified dimension, when plotted at different scales, what will be its dimension on map is shown in Table 3.
Table 3 : Features on hard copies at different scales
| Dimension of Feature (m) |
Feature in mm on maps at scales: |
| |
1:1,000 |
1:2,000 |
1:5,000 |
1:10,000 |
1:20,000 |
| 50 |
50 |
25 |
10 |
5 |
2 |
| 30 |
30 |
15 |
6 |
3 |
1.5 |
| 20 |
20 |
10 |
4 |
2 |
1 |
| 18 |
18 |
9 |
3.6 |
1.8 |
0.9 |
| 15 |
15 |
7.5 |
3 |
1.5 |
0.75 |
| 12 |
12 |
6 |
2.4 |
1.2 |
0.6 |
| 10 |
10 |
5 |
2 |
1 |
0.5 |
| 9 |
9 |
4.5 |
1.8 |
0.9 |
0.45 |
| 6 |
6 |
3 |
1.2 |
0.6 |
0.3 |
Users of different types of maps (only indicative).
The users of full topographical maps at all scales may include:
Statutory Authorities in a State
- Urban development authorities - Town Planning and Engineering wings
- Local authorities - Engineering and Health Departments
- Agencies for Urban Water Supply and Drainage system
- Agency for Transmission and Distribution of Electricity
- Agency for Clearance/Improvement of Slums
- Agency for Housing.
Departments of a State Government
Department of Town Planning
- Department of Survey Settlement and Land Records (City Survey)
- Public Works Department
Statutory Authorities/ Departments of the Union
- Bharath Sanchar Nigam
- Central Public Works Department
The users of skeletal maps at all scales include:
Departments of a State Government
- Police Department - crime detection, law and order, traffic
- Fire Force Department - reach the fire spot
Statutory Authorities/ Departments of the Union
- Department of Posts
- Election Commission
- Census Commission
Process in planning - Best Practice
Requirement of maps in terms of content, accuracy, scale, etc. in planning and development of urban areas can be appreciated well when the process involved in planning for physical development and implementation is known. Planning urban areas, especially metropolitan areas and cities, may have three stages, although they can vary:
- Outline Development Plan (ODP) now re-christened as Perspective Plan, at macro (city/town) level;
- Comprehensive Development Plan (CDP) also at macro level. This can also be called Master Plan;
- Zonal Plans for part of city/town to elaborate the details; and
- Town Planning Schemes at micro (local) level to implement the plan.
These levels are basically to perceive, conceptualise and see details from city/ town level to part of city/town and local level. These levels, naturally require maps at different scales with different content with one or fewer maps to see the area under consideration.
For instance for planning a metro rail system or a bypass for rail or road, entire metropolitan area or city as the case may be has to be on only one or two sheets for all to see the alignment at metropolitan or city level. To fine tune the alignment, to avoid insurmountable obstacles, more and more details will be needed for which maps have to be at larger and larger scales. Only important features are shown on maps at small scale. All the features would be required at detail planning. What features in base map and what elements in plan proposal need to be shown on map user (planners, public and decision makers) determine the scale(s) for maps at a particular level.
Preparation of Master Plan
Preparation of Master Plan at Metro/city level is highly complex and needs multi- disciplinary team of experts. However, the experts who steer the work on planning are the physical planners. Before embarking on making projections for demographic aspects to estimate the land required to meet the growth during the plan horizon, several studies are carried out by physical planners apart from other discipline. Most important planning survey is the use of building and parcels of lands, not only in the existing developed area but also in the vicinity, what is called Local Planning Area, a statutory area declared under the Town and Country Planning Acts in all the States.
Planning studies: Statutes on Town and Country Planning in all the States require preparation of Existing Land Use of every plot/property. Land uses are classified broadly in to 8 main groups. Not only that, a register showing the land use of every property need to be prepared and maintained along with the existing land use map. Hard copies of maps must be as large as 1:1,000 to mark the land use in field and to prepare fair maps in office. A GIS in deed, but in hard copy form.
Another planning survey for physical aspect is structural condition survey. This survey assumes importance in old areas due for redevelopment and/or rejuvenation. Structural condition of buildings are classified in to 4 or 5 classes: very good, good, moderate, poor and obsolete. This survey is for structures for which each and every structure must clearly be available on maps to mark the appropriate condition in the field and to prepare fair maps in office. For this purpose also maps must be at least 1:1,000 if not at 1:500. This is yet another GIS earlier to electronic era.
All these maps need to be documented for reference and record, lest they are called for in courts of law. Large-scale maps show limited area on a sheet. They need to be generalized to prepare smaller scale maps: 1:5,000, 1:10,000, 1:20,000 to depict parts of urban area or the whole urban area on one or two sheets. The principle of Part to whole is applied which is similar to preparation of smaller scale maps from survey data at larger scale.
Planning studies other than Land Use and Structural Condition are for:
- Density of population/house holds;
- House hold survey for social, economic conditions which is a sample survey;
- Traffic and transportation survey;
- Problems in physical condition like congested areas, narrow roads, bottlenecks, bad junctions, low lying areas, pollution from industry, etc.
All these surveys are not aimed at each and every property and maps at small scales, say 1:5,000, 1:10,000 and 1:20,000, may suffice.
Analysis of the physical aspect - Land Use and Structural Condition - and socio-economic aspects, problems in physical form, function, need to be made and results shown on small scale maps: 1:5,000, 1:10,000 and 1:20,000.
After the land requirement for future growth is established, land availability has to be analysed for suitability for development. To show the results of the analysis as thematic maps also smaller scale maps, say 1:5,000, 1:10,000 and 1:20,000, area required.
Result of each of the study on separate maps (transparencies) at smaller scale (all at same scale) will be compared with one above the other (sounds like GIS in place!) to synthesis the studies and draw inference. The maps showing the results of planning studies at small scales, on one or two sheets, are the basis on which alternative plans at macro level are conceptualised.
Concept plans: Concept plans are free hand sketches on the base of accurate maps, at smaller scale (1:10,000 or 1:20,000 depending on the planning area) on one or two sheets, to show the boundaries of land areas for different uses, arterial and lower order road system, railway system, density of population/ house holds, etc. However, boundaries of proposed land uses and road system will not have any definite geometry.
Master Plan: After a concept or combination of two or three is accepted, Master Plan (CDP) is prepared on accurate map at larger scales, say 1:20,000 or 1:10,000 (for Metros and large cities), and 1:5,000 for others.
Format for large scale topographical maps
Topographical maps for urban areas at large scales on modular UTM grid system have the following formats and coverage:
| Scale |
Format |
Coverage |
| 1:1,000 |
1,000 x 500 mm |
1.0 x 0.5 km |
| 1:2,000 |
1,000 x 500 mm |
2.0 x 1.0 km |
| 1:5,000 |
800 x 400 mm |
4 .0 x 2.0 km |
| 1:10,000 |
1,000 x 500 mm |
10.0 x 5.0 km |
| 1:20,000 |
1,000 x 500 mm |
20.0 x 10.0 km |
The format, internationally adopted, generate unique four digit (5 or 6 digit for 1:1,000) sheet numbers. Numbering system is scalable in future for maps of adjacent areas in any direction.