Physical information inputs for planning agencies

Basic information attribute to be supplied by the urban agencies

a. Socio-economic data

Plot ownership and other attributes; Property ownership and other attributes; Agricultural/ villages inhabited area socio economic data will be collected/ collated by local authorities for information

b. Boundaries (with pillars, if any)

Municipal ward; Defence land; Government land; Names of localities and important landmarks

c. Any other information (attribute) as desired

Revision and updating of urban digital data

Preparation of Municipal Information System will entail major efforts in generation of physical database. This is a common scenario in all developing countries, as all the information required for GIS is not readily available.

After the data base is prepared through the photogrammetric process, it will be incumbent on the authorities to update the database. Major physical changes take place on the periphery of the town. Fast growing town, will have a lot of changes in building, roads, parks, drainage, landuse and infrastructure and a host of underground utilities. It is therefore suggested that digital database should be kept updated with the help of fi eld visits, aerial photographs/ high resolution satellite imagery and verifi cation by ground surveying techniques, especially GPS.

Smallest size of ground object on aerial photography

Taking 20 microns (1 micron = 1 mm/ 1000) as the resultant resolution of aerial negative; the minimum size of object on the ground, which will be visible, is 20 microns X 8000 (scale) = 160 mm or 16 cms on orthophoto. It means that most of the distinct manholes or equivalent sized objects will be visible on the aerial photograph.

The aerial photography in India is generally carried out by the National Remote Sensing Agency (NRSA), Hyderabad. The modern camera, which NRSA uses, is fitted with GPS and Image Motion Compensation (IMC) device. This entails signifi cant reduction of field control and improves the quality of aerial photography. The quality of aerial photography adheres to world contemporary level.

GIS

GIS is basically a comprehensive spatial decision support system based on geo-referenced digital database, computer hardware/ software and non-spatial attribute data. The spatial data is obtained from satellite imagery, aerial photography/ photogrammetry, GPS and ground visits. Preparation of the digital database is 70 – 80% of total efforts for the establishment of the GIS. The digital database, once complete, will be a big fi llip towards establishment of GIS.

Municipal Information Functions

It is our objective to design an operational and dynamic Municipal Information System, which will be greatly facilitated not only by the generation of a detailed Digital database but also which can be easily accessed, updated and analysed for different purpose.

It is proposed that the GIS will cater to the data requirements of all the departments. The provision of a common database and access to it by the various departments of planning, property, finance, engineering, industry, personnel and that of marketing and rural development will not only increase efficiency and productivity but also go a long way for future decision support system.

The section below indicates the possibilities that exist each of the departments. The Engineering Department would not only be able to have a complete grasp of the existing situation, but also plan for the design of new roads and facilities. Detailed utility mapping showing the exact spatial location of the water supply lines, the sewerage network, the telephone and electricity supply lines would go a long way in providing optimal services and increasing revenues. The detailed spatial database would also provide the ideal basis for the monitoring operations and maintenance of existing assets.

The Planning Department would require detailed landuse maps, which would not only help in the preparation of the new Master Plan but also help in the process of monitoring. The contents of same database can be used to develop an approval system wherein the process of building/ plan sanctions can be approved online or with minimal paper work.

With respect to Revenue and Cadastral Management system the detailed base map can be used as a base to develop a monitoring mechanism with the details of the properties, their current value and the rate of taxation, etc. This will give a clearer understanding of current status of properties related to their various aspects and thereby help in initiating processes for revenue collection. Once a detailed digital database is created, the contents of this would be used to develop webbased application. The web based applications can not only be used to inform and interact with the public, but also reduce paper work, increase efficiency and if necessary limit direct contact with the public to a minimum.

Urban Digital Orthophoto

Orthophoto by definition is an aerial photograph, which has been caled and does not have geometric distortion (tilt and relief distortions). Photogrammetric process is carried to the stage of Aerial Triangulation which then helps in generating the digital terrain model of the overlapping photographs (model). The DTM generation will be carried out in two phases, in phase I, the automatic terrain extraction will be processed which will be followed by manual editing to incorporate the break lines and rectifying the inconsistency of contours to fit the terrain. The resultant DTM is made as an input to generate dimensionally accurate Orthophoto.

Map Updation and Maintenance System

A modern coordinated cadastral system requires regular Maintenance. To keep the records up-to-date and without losing the reliability of data, the cadastral maps have to be updated from time to time. A programme of renovation would be required to be incorporated into the regular surveys replacing the coordinated points which are lost, disturbed and become invalid.

Land Information Technologies – Regulating the City

Regular Monitoring for Encroachments

Encroachment of government land and unauthorized construction are very much a common feature of any urban centre. By comparing the base maps of different epochs of time one can get the handle on the extent of encroachments and its location. The technology of producing the base maps will be suitably designed to get authentic extent of the encroachment.

Environment Monitoring

This function in managing a city has recently gained a major dimension.
The fact is that public perception of a city administration is judged mainly by the way environment is officially monitored. The proposed design will be able to provide working information on:

Inventory of all trees and vegetation (type, location) as Bench Mark study. Any subsequent change will be measured with respect to this Bench Mark Surveys.Establishment of urban village boundary (Lal Dora) – Village boundary determines the land use of urban village. This should be clearly established on the map in an unequivocal manner.

Financial Aspects

The cost of the Design Proposal will depend on the following:
· Technical Activities
· The Managerial decisions about the phases for the production and its strategy.

Strategy of Production Phases / Scheduling of Investment

Decision about these phases becomes important to reduce the budget allocation per year. For example, aerial photography (which is not costly) should be ordered for the whole area of town. Similarly, field control (GPS operations and leveling) is also essential for the whole area. Once these two items are done, the process of aerial triangulation can proceed at convenience. This is a low cost item and can be taken up for the whole urban area. After incurring this cost, the decision of the Agency (or several agencies) can be taken to spread the cost of mapping to a longer period of more than one fi nancial year by asking for photogrammetric mapping of only a small portion of the town. This is being suggested as the major cost of mapping lies in the photogrammetric plotting. A suggestive cost pertaining to the various processes/ activities is given in table 2.

Conclusion

The proposed design of a mix of the various available technologies in India will provide a robust, reliable, comparatively low cost and easily operable Information Base in digital and paper mode. The various agencies can pool their part budget(s) towards the cost. The ideas suggested in this paper could easily be converted to Prof P Misra Consultant, Land Information Technologies, New Delhi, India misralit@hotmail.com a project/ tender and can be easily accomplished through Public Private participation in the matter of one to one and half years. The most difficult part is to make a beginning.

Yet another feature of the design is that the data base will provide the utmost accuracy which is primarily required for engineering projects and establishing encroachments in the ‘final’ sense. There will be permanent landmark on the city for further accurate work or the re-establishing ‘rights’/ right location in legal sense.