This chapter reviews the impact of computers on the surveying and mapping of land parcels, and on the recording and dissemination of land-related information. The main advantage of computerization is the speed with which data may be handled.
Computers can, inter alia, be used to:
The list of possible applications of information technology (IT) is almost endless. It is often as valid to ask whether a country can afford to be without a good computerized land information system as it is to ask whether it can afford to install one.
Computerization speeds up the processes of field and photogrammetric survey, the storage, retrieval and analysis of data, and the preparation and production of cadastral maps and plans. Automatic data recording has two advantages - it reduces the human mistakes that occur in writing down and subsequently transcribing field survey observations, and it facilitates the transfer of data for subsequent computation and adjustment. In spite of the increased cost of modern surveying equipment, productivity can be significantly increased through the use of computers. This then makes it possible to reduce the unit costs of survey.
While new surveys may benefit from the availability of computer systems, many records already exist only on paper, for example in written records or on paper maps. Old records must be converted into computer-readable form if the advantages of modern information technology are to be realized. The conversion of existing maps and graphic images into digital form is usually done by “digitizing”. The technology for digitizing maps is readily available, though the processes are often labour intensive and remain expensive. Textual data relating to land parcels may be converted into digital form either by typing the data into a computer by long-hand methods using a keyboard or typewriter, or by scanning. In the latter case, the data may either be stored as scanned graphic images and reproduced when necessary as facsimile copies, or else they be converted into individual characters using pattern recognition software.
Without doubt the most expensive and time consuming part of setting up any computerized cadastral system lies in data conversion. The cost of entering data into the system can account for 70 percent to 80 percent of the total initial costs of getting the system operational. Fortunately the cost of data storage has decreased significantly over time while the speed of data retrieval has increased as a result of the more powerful computers that are available, especially in desktop form.
The priority in many cadastral systems is to manage textual records more efficiently rather than to produce digital cadastral maps. Text data may include the property reference number, the name and address of the proprietor, the title number and form of tenure, details of any mortgages, subleases or assignments, any caveats, and possibly details of annual rents and rental payments and their due dates. In addition there may be references to survey plans, land-use zones, planning applications, etc.
While it is often relatively straightforward to computerize textual records - for instance a deeds register - it is rarely cost effective to “computerize past mistakes”. Since computers cannot tolerate the types of imperfection in the data that arise in manual, human information processing, the opportunity should be taken to improve the quality of existing data and purge the records of errors that have inevitably occurred over time. The opportunity should also be taken to overhaul the procedures that are followed. Often the benefits of computerization stem more from data and system reorganization than from the use of computers per se.
It is not necessary for all data to be stored within one system as long as access to the data can be gained when necessary. Connecting a series of computers together into networks covering local or wide areas is becoming more common. Through this means data can be collected, stored and updated in several different locations. Thus the Registrar of Titles may hold the definitive record of who owns the land while the Ministry of Finance may hold the land tax assessments; the municipal planning department may hold data on land use while data on sewers, water and electricity may be held by public utility companies. Each of these data bases can be linked together and data exchanged as and when needed.
Because of the high cost of data capture and maintenance, data must be shared if cadastral systems are to be cost effective. It will often be found that data sets are incompatible for one reason or another - they may for example contain different parcel referencing systems, the Registrar of Titles using a Volume and Folio system for identifying parcels while the tax assessment may have a totally different system such as a sequential number with no spatial attribute; or the data sets may relate to different definitions of areal units, the taxable unit being defined by land use while the registered title relates to land ownership. If data are to be shared, then common standards must be agreed.
Once data of appropriate quality have been entered into the system, various processes of manipulation can take place. These may take the form of geometrical transformations of the data for better graphic display; or mathematical calculations including the aggregation and generalization of data; or the extraction of particular categories of data either on the basis of attributes or combinations of attributes or in accordance with their location; or simply providing data as part of a management information system. Thus for example, the dates at which documents are passed from one section of a cadastral office to another or to an outside department can be checked, reducing the chances of documents being lost or identifying files where the processing of transfers and applications have failed to be completed by certain dates. Serious delays can then be investigated. Improved management information systems offer one way to improve cadastral systems.
Processing of the computerized records can also be undertaken using what have become known as geographic information systems or GIS. A GIS consists of a data base, graphic facilities and software for data processing. Using a GIS, different data can be retrieved from the database, or data can be taken from two or more data sets and overlaid on the graphic screen or printed out on hard copy such as paper. The computer can carry out spatial searches, such as locating all properties that fall within a specified distance of a proposed new road alignment. Estimates of the cost of acquiring any land can then be made automatically on the basis of the area affected and its estimated value per square metre.
An essential element in any cadastral system is the communication of information either in the form of reports, lists or graphic display. Computers can be used either to display data on a screen or to drive a plotter that produces maps or text in hard-copy form.
In order to make full and effective use of a computerized cadastral system, a corporate strategy should be developed so that potential users of the system, especially other government departments and parastatal bodies, can gain access to it. First, the potential users of the system need to be identified and a feasibility study undertaken to determine how much land-related information is passed between ministries, departments and other organizations and whether the installation of a computerized network is justifiable. After the feasibility study, a user requirements analysis should be undertaken, identifying in detail the resources already available and the type and quantity of data that will need to be processed. Immediate and longer-term requirements should be considered since, if successful, the system will inevitably grow.
From these studies, an implementation strategy can be worked out to determine, within the resources available, what new equipment and training are needed. The implementation strategy should lead to a technical specification that will be described in an Invitation to Tender (ITT) that will be sent out to system suppliers. The ITT document will give details of how any system is to be evaluated (known as the Benchmark Test) and the form of the acceptance test that will be required at the end of the project. Based on the responses to the invitation to tender document and the results of any benchmark tests, the best supplier will be chosen. After suitable contractual arrangements, the system can be installed and acceptance tests carried out to ensure that what has been delivered performs in accordance with the specification. Often there may be a pilot project over a limited area to ensure that the tasks have been correctly specified.
Purchasing and installing a computer system is only the start of a process of change within an organization. A computerized system will need to be maintained and this can be expensive. Technology is changing so rapidly that new equipment will need to be installed in a relatively short time. New institutional arrangements will need to be developed as the objectives as well as the practices within an organization evolve. Computerization is a dynamic rather than a static process.
A major constraint on the implementation of change within a cadastral organization is often the lack of coherent land information policies. In many developing countries there are no consistent policies for the provision of mapping, or for the supply and updating of land information. The position is often mirrored in the lack of coherent policies for the sustainability of urban or rural development. The position with regard to information resource management is little different. There is often no attempt to recover the costs of collecting, processing and distributing cadastral information nor are there plans to keep the data up to date. Frequently the investment in information technology is not supported by a business plan.
While the technology is important, the essential characteristic of a cadastre is that it is an information system, not a set of technological tools. There are of course many technical problems in data integration and in sharing data across networks. The greatest difficulties, however, lie in the human, legal, political, and economic problems that concern all potential users and which must be addressed. In providing greater access to data that are held by other people or other organizations, it is necessary to clarify the rights and obligations of both the data producers and the data users. A number of specific problems can arise, such as protection of the rights of an individual to privacy. Such protection can be achieved by:
The confidentiality of data is more difficult to protect since a legal definition of “information” and what constitutes confidentiality are difficult to lay down.
Before investing in computerized cadastral systems the question must always be asked as to whether the organization concerned can afford to invest in high technology. This is especially so in developing countries, most of whose governments are already heavily in debt. Computerization inevitably involves the expenditure of hard-earned or borrowed foreign exchange. Furthermore there is always a fear that computer technology will reduce employment. Present evidence, however, suggests that there will be changes in the nature of employment but that in the short term at least, employment opportunities may increase. This is because the massive task of data conversion will keep many people in work for a decade or more.
An assessment of the costs and benefits is a prerequisite to computerization. The benefits in part depend on the ability to sell information. Cadastral data can be a valuable commercial asset and hence the cost of cadastral surveying can be offset by the sales of the resulting data. Increasingly, governments are requiring their ministries and departments to find ways of recovering the cost of running their services. In many less developed countries there is, however, still a view that “government should pay”. If the introduction of high technology is successful, then productivity will increase significantly. That alone may not however justify the level of investment. It may therefore be necessary to recover more of the capital costs through the sharing of data and by the sale of the information gathered. Information is a marketable resource and some of the cost can be recovered by selling data to the private sector. If full benefit is to be gained from the sale of data, then the information must be protected through copyright laws. After some initial uncertainties in many jurisdictions, it is now generally possible to protect intellectual property rights including those where the base information is stored electronically. Collections of facts such as maps, lists and pieces of text can all be treated as intellectual property.
Improving existing cadastral systems and the development of information as a corporate resource pose philosophical, technical and institutional problems. Central to their solution is better education and training. On the technical side, with many of the more complex systems, it can take months if not a year for an operator to become fully confident with the system. Although systems are becoming more “user friendly”, their complexity makes it difficult for local operators to understand the full functionality of each system. Suppliers of systems usually include the cost of basic training in their tender price. Such training needs to be sustained as the trainees become more confident and capable. Training in continuing professional development should be a major investment in any organization.
This chapter has touched on a number of issues, both technical and institutional that lie in the way of developing a computerized cadastral system. The cadastre deals with two resources - land and information. Computerization facilitates the better use of both by allowing more people to know more about the land and the problems and opportunities associated with its use. While much can be achieved through improved manual methods of data handling and by focusing the attention of administrators and the public on the integrated nature of many land-related problems, it is computerization that is the most effective catalyst for change. Pressures on land are growing in every community both through population growth and through environmental and ecological change. To monitor, plan for and manage that change, better information is needed. Computerization of cadastral records offers vital support for such activities.