IAAS, Department of Archaeology
University of York, The Kings Manor, York
GIS can act as a useful tool if a conservation policy is properly defined for historic cities.
Urban areas are complex multi-dimensional systems evolving out of an interaction of multiple agents at several levels. At any given singular moment of time, several transformations may be occurring simultaneously, which every human being perceives differently and comprehends individually. Kant saw time as a ‘collective singular’ which everyone uses to order the world, but each of us experience in our own separate ways. These individual experiences result from the perceptual and cognitive processes in the human brain that also determine the meanings that we derive from our surroundings. These perceptual processes also determine the image that is created in the human brain of the environment around us, and is a selective process influenced by our cultural and social positions. This process of formation of mental images through individual experiences and recollections is always rooted in the spatio-temporal context and by forming connections between the past and the present it can help us in assigning values to the remains from the past and justifying the need for their continuation into the future.
The Integrated Approach
The historicity of a city cannot be confined solely to any rigidly demarcated zone but has to be seen in totality over the whole landscape. Conservation professionals in India have been advocating strongly for this ‘integrated approach’ since the last few years, but have not been successful in being able to evolve policies and practices which can bring together professionals from planning and conservation together. It is however unimaginable how a process can be partitioned into planning and conservation needs when both concern themselves with the ‘city’. As long as we do not move away from the definite constraints of a Master Plan process and do not bring the user to the forefront, the city will continue to be seen as a system of roads, transport networks and dispersed physical entities.
Any Conservation or Management efforts have to begin with letting the people discover a common position regarding the past, which helps demarcate what people form associations with or identify their existence in the city with, and not solely by an associated value of ‘timelessness’ that may be attached to it. As people form these associations through internal recollections that are rooted in their collective memories, ways have to be found to map these mental models and collate them with the physical dimensions which are much more easily mapped. Researchers are increasingly looking at ways to model such internal perceptions and experiential constructs and also the interconnections and networks that exist in the thought processes leading to such mental constructs. These mental images have been interpreted into what are termed as ‘cognitive models’, and most consumer-oriented enterprises are now moving towards the adoption of such exercises at different levels of the organisation to be able to define their aims, policies and goals depending on the result of such exercises. Direct application of such mapping techniques in planning and urban management is yet to be seen where the reliance is still largely on the physical networks for analytical purposes rather than on any mental ones.
GIS applications: Possibilities and Limitations
With a number of agencies and organisations involved in planning and conservation in Indian cities, the integrated process can well be a ‘participatory process’ where GIS can serve as a common platform and interface that permits data exchange and collaborative decisions. Although most data in GIS has to be geo-referenced, non-commercial solutions such as those in the environmental context are now looking at ways to integrate non geo-referenced information in GIS. This can be particularly useful when historical maps are to be used for research. Most historical maps have very different co-ordinate references than those used in the current Survey of India maps. Overlaying of such maps to find common denominators has been a problem in manual processes; partly because of the way these have been scaled or referenced and partly because often these were not geographically accurate but mostly cognate representations incorporating symbolic and metaphoric imagery.
Techniques such as ‘rubber sheeting’ in GIS can help adjust the historical maps and find common reference points with present maps. However, it is still a research issue as to how the metaphoric representations in historic maps can be related to the SOI maps to be able to accurately decipher the transformation that has taken place in the overall spatial the historical maps and find common reference points with present maps. However, it is still a research issue as to how the metaphoric representations in historic maps can be related to the SOI maps to be able to accurately decipher the transformation that has taken place in the overall spatial structure of the city. Our increasing reliance on rigid, cartographic renditions makes these historical maps extraneous which can otherwise be a very useful resource for lending an insight into how perceptions of people have evolved over time. Although commercial GIS packages are still incapable of applying statistical analysis to such ‘loose’ representations, there have been a few recent efforts to integrate ‘perceptual maps’ in the process of understanding of our environs, and such integrations could be made more effective by developing analytical techniques that need to be and could be applied to such cognate models. Conversions of such models into networks have been attempted in organisational software such as ‘Decision Explorer’. Whether visual renditions can be converted into networks for analytical purposes in the urban context would depend on the kind of information that we seek out of them in the process. It can be highly useful if such statistical analytical packages can be linked with GIS, allowing the interchange of data that is mapped as network structure and as visual spatial representations.
Databases for managing large data sources in the listing of historical buildings or census details are now being widely used, but the correlation of data from more than one source is still mostly limited due to data protection policies that exist between various organisations. GIS can provide a base for the spatial and non-spatial data to be interlinked, and by developing techniques such as relational databases or object-oriented databases in GIS an added advantage of linking non-spatial data across several levels can be realised. Research in the field of ‘multiple views’ is working towards the creation of parallel views where the same datum can be viewed across several different maps or layers of spatial information. In this instance, GIS provides the advantage of linking databases to information from maps that may be created in other software packages such as ‘AutoCAD.
GIS allows for data input from such diverse sources as remote sensing, traditional cartographic maps, aerial photographs and other photographic images. It can be hoped that the data dissemination policy in India will soon be defined for less restricted data exchange and data from remote sensing and other satellite information would be easily available for commercial purposes. Most European countries have relaxed their data protection rules, which allows for better exchange of data at a global level. If historic cities are being seen as global resources and the preservation of them is to be seen as a global responsibility, then it is fair to hope for information to be much more conveniently accessible at a global level. With the Internet forming the prominent interface where most global communities interact, more and more data resources are being made available on the World Wide Web, and any GIS application in the Indian context will benefit from a flexible national policy for data dissemination allowing for greater exchange.
The development in the field of ‘fuzzy logic’ and ‘Artificial Neural Networks’ is providing the option of incorporating indeterminate and ambiguous information from the real world into GIS. This will be particularly useful while considering cognitive models and individual perceptions of people and incorporating them for reference into GIS, and also while recreating information from the past into the present. Most commercial GIS packages have some basic statistical analysis techniques available within them that need to be explored for resource management applications. Besides these basic applications, several other statistical packages such as SPSS can be linked to GIS. The application of such analysis to abstract attributes such as ‘historicity’ and ‘cultural values’ is certainly an issue for further research although this has been attempted in a few archaeological applications.
The real world cannot solely be represented in two dimensions as is commonly accepted. This is certainly a very limiting view of the reality that we perceive around us. Most modelling in GIS has been two-dimensional especially in the context of urban planning applications. GIS has been used largely to analyse transport and communication networks and it can safely be said that most planning applications in India still rely on plan-based analyses considering only the projections on the ground. This is not how we perceive reality. ‘Reality’ exists for us with all its phenomenological associations, and the geographies around us are perceived through all senses; tactile, visual, olfactory and auditory. Three-dimensional display in GIS was found to be limited in being primarily elevational and research has focussed on developing this aspect. Multimedia extensions and Virtual Reality interfaces with GIS have emanated from this need to develop more perceptual imagery and softwares such as ‘Gis 2 Ve’ provide flexible interfaces to simulate geographical information in a virtual environment. Immersive technologies in VRGIS allow the user to interact with the simulated environment and recreate the sensations that may be felt in interaction with the real world. These techniques are moving away from the ‘fixed position’ observer to ‘multiple viewpoints’. DTM (Digital Terrain Modelling) and TIN (Triangular Intersection Network) can be very useful in the analysis of landforms and in the determination of the trends of human occupancy and resultant transformations.
Plans are afloat to use GIS as a tool for the preparation of the next Master Plan in New Delhi, and it has already been used for such planning applications in Mumbai. The application of GIS will probably involve immense upheavals in organisational and financial terms. However, it has to be realised that an optimum use of this application cannot be achieved unless the benefits that are we hope to derive from it are clearly defined. This will need a two-step methodology. Firstly, the aims and objectives have to be clearly defined for the project and a full review of the limitations of the presently employed techniques must be conducted. Secondly, GIS has to then be assessed to see how it can be used to derive maximum benefit from it, and the changes that would be needed in the present scenario in turn to help derive these benefits. If a conservation policy is properly defined for our historic cities, GIS can act as a very useful tool to help us understand our cities better. Otherwise, it can just end up being used as a mere data storage system.
- Cinderby, S. (1999) Geographic Information Systems for participation: The future of environmental GIS?; International Jnl. of Environment and Pollution.Vol.11 (3), in press.
- Canmara, A. S. and Raper, J., ed. (1999) Spatial Multimedia and Virtual Reality, London, Taylor and Francis.
- Coccosis, H., and Nijkamp, P., ed. (1995) Planning for our Cultural Heritage, Hants; Avebury.
- Duncan, J., and Ley, D., ed. (1993) Place/ Culture/ Representation, London; Routledge.
- Friedman, W., (1990) About Time: Inventing the Fourth Dimension, MIT.
- Gosden, C., (1994) Social Being and Time, Oxford; Blackwell.
- Haapala, A., ed. (1998) The City as Cultural Metaphor, Vol.4
- Hall, P., (1992) Urban and Regional Planning, 3rd ed., London; Routledge.
- King, A. D., ed. (1996) Re-presenting the City, London; Macmillan Press Ltd.
- Langran, G. (1992) Time in Geographic Information Systems, London, Taylor and Francis.
- Leach, N., ed. (1997) Rethinking Architecture: A reader in Cultural Theory, London; Routledge
- Maccormac, E. R. (1985) A Cognitive Theory of Metaphor, The MIT Press.
- Maceachren, A. M., (1995) How Maps Work: Representation, Visualisation and Design, New York; The Guilford Press.
- Maguire, D. J., Goodchild, M. F., and Rhind, D. W., ed., (1991), Geographical Information Systems, Vol. 1 and Vol.2, Essex; Longman Scientific and Technical.
- Molyneaux, B. L., ed. (1997) The Cultural Life of Images: Visual Representation in Archaeology, London; Routledge.
- Paulsson, B. (1992) Urban Applications of Satellite remote sensing and GIS analysis, Washington; The International Bank for Reconstruction and Development.
- Rappoport, A. (1977) Human Aspects of the Urban Form, Oxford; Pergamon.
- Rodaway, P. (1994) Sensuous Geographies: Body, sense and place, London; Routledge.
- Shields, R. (1991) Places on the Margin: Alternative geographies of modernity, London; Routledge.
- Tolman, E. (1948) Cognitive Maps in rats and men; Psychological Review, 55, 189-208.
- Tscumi, B. (1994) Architecture and Disjunction, MIT.
- Turner, T. (1996) City as Landscape: A Post Post-modern view of Design and Planning, London; E&FN Spon.
- Walsh, K. (1992) The Representation of the Past: Museum and Heritage in the post-modern world, London; Routledge.