Sanderson Townend &Gilbert uses the geographic information system ArcView to translate screen data to the ground. Human judgment is backed up, clients are better informed and the firm benefits. John Kirkwood reports
Many property organisations have recognised that intelligent and appropriate use of information technology is a useful selling point.
Geographic information systems (GIS) technology, for example, has enabled chartered surveying firm Sanderson Townend & Gilbert (ST&G) of Newcastle upon Tyne to expand its retail agency business.
Although the traditional property terrier has all the essential elements of a GIS – maps, data and explicit geographic references linking the two -such paper-based creations provide very limited search facilities and little or no opportunity for data analysis.
Implementing the GIS concept using computers, however, provides a wealth of opportunities that the property sector is only just beginning to explore. ESRI, which supplied the ArcView GIS used in this study, alludes to these possibilities on its Web site http://www.esriuk.com/:
“A geographic information system is a computer-based tool for mapping and analysing things that exist, and events that happen, on earth. GIS technology integrates common database operations such as query and statistical analysis with the unique visualisation and geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises.”
ST&G used ArcView 3.0 to identify and purchase sites throughout Britain on behalf of Global Video, a Scottish company which operates a chain of video stores. As the firm’s Paul Stevenson states: “It was apparent after relatively little use of GIS that population data, in addition to more commonly used property data, could be vital in providing superior acquisition advice to the client.”
ST&G used a number of datasets for the Global Video project, in addition to the ArcView mapping software. These included boundaries of postcode sectors from Geoplan (supplied as polygons); raster mapping from Bartholomew; Goad digital maps, and demographic data supplied by CACI. In addition, data about Global Video’s main competitors in the video rental business were extracted from the Internet.
Computer-based maps are supplied in either raster or vector format. Raster maps can be created quickly by scanning existing paper-based sources. A map is represented by the pixels that form the screen display, in the same way as any other image. In contrast, with the vector model, information about points, lines, and polygons is encoded and stored as a collection of x, y co-ordinates.
Mapping packages
Raster data is cheaper than vector data and is said to be more useful for mapping continuous features (eg income levels by postcode). Bartholomew, a division of Harper Collins Publishers www.harpercollins.co.uk/maps, supplies its 1:250,000 map dataset of Great Britain for just £700.
The demographic data supplied by CACI include population data from the 1981 and 1991 censuses. CACI Information Services www.caci.co.uk was the first accredited Census agency in Great Britain, and claims to have processed more censuses worldwide than any other company. For the ST&G project more than 120 data fields were provided for each postcode sector, including household sector, unemployment, car ownership and social class.
Finally, ST&G used Experian Goad’s digital data. This covers every major retail centre in the UK, and is available in digital format for use by retailers, property companies, local authorities, planners and surveyors http://www.experian.com/corporate/press_releases/102197.html. Users customise their own plans, or configure their own national or regional view of competitor activity, utilisation of space or size of retail outlets. Thus, S&TG extended the original data on the basis that additional local information provides the cutting edge.
ST&G currently runs ArcView on a 100Mhtz Pentium PC. This GIS package provides the mechanism to integrate and use the datasets described above.
A possible map location is first identified and then GIS selects the postcode sectors for the proposed video store’s catchment area. This provides data to see if those sectors conform to ST&G’s demographic model for a successful store. Once the site is identified, a visit takes place. Thus the human-judgment element is not replaced but is simply and effectively enhanced by the technology.
Michael Quinn, managing director of Global Video, states: “When my management team is called by ST&G to view a potential new site, I’m confident that the property will invariably suit our needs. The technology genuinely adds value to the advice we receive from ST&G and helps us to remain focused on our business objectives and the operational viability of our outlets.”
The use of GIS as an aid to site selection is not new, of course. As ST&G’s Stevenson stated in a paper to the RICS1: “The technology has now gained wide acceptance among large retailers, such as Boots, WH Smith and Marks & Spencer.”
Similarly, using CACI’s InSite and Impact GIS products “retailers can build sophisticated analyses of their marketplace and of their customers which can then be applied to business issues.”
Client assistance
The encouraging feature here is that a GIS system is being used in-house to advise clients who cannot warrant undertaking such work themselves. Stevenson says: “These companies are not large enough to justify their own geographic information systems, and therefore turn to practices such as ST&G for assistance.”
Although using technology to enhance professional services is a progressive development, it is clear that more could be achieved. It was evident from ST&G’s system that the level of analysis could be stepped up.
There is a real danger that GIS is used more as a marketing tool, rather than providing sophisticated analyses of retailers’ requirements.
ST&G recognises the value of obtaining data from a number of sources, and understanding it, before it can be incorporated into GIS. There is also significant scope for greater refinement of the data used.
Data analysis could also be improved by the use of more advanced statistical tools such as MathSoft e-mail: int-info@mathsoft.co.uk.
Finally, the full benefits of new computer technology can be realised only if appropriately trained staff are available within a company. Sanderson Townend & Gilbert employs a GIS graduate and the project is supervised by a chartered surveyor. But generally within the property sector more needs to be done to develop a wider acceptance of the role of GIS as an aid to professional practice.
John Kirkwoodis course leader for the MSc in property information management at Sheffield Hallam University. e-mail j.s.kirkwood@shu.ac.uk
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ArcView data access l Reads map data directly from shapefiles, ARC/INFO, PC ARC/INFO, ArcCAD, AutoCAD (DXF and DWG) and Intergraph (DGN). Directly import map data from MapInfo, Atlas GIS and ASCII.
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ArcView key features l Easy-to-use interface
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ArcView data analysis l Performs spatial queries.
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ArcView system requirements Processor: 486 or higher MS Windows (3.x, 95, or NT) 12-16 Mb RAM Disk installation: 57 MB – Typical 24 MB – Compact |
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Traditional firm updated ST&G provides traditional professional surveying services, including commercial agency, property management, valuation and building construction-related work for both local and national clients from its Newcastle headquarters and offices in Stockton, York and London. Last year its senior partner, Peter McKendrick, was elected president of the RICS. During his term of office he championed the cause of GIS for property applications. |
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Reference 1 The use of GIS for computer-assisted decision-making in site selection. A paper submitted to the RICS Research Review Series Buchanan, H; Fairbairn, D; Parker, D; Stevenson, P; Taylor, G; and, Wall, J. |
