25 Integrating spatial information in computerised Sites and Monuments Records : meeting archaeological requirements in the 1990 s

Most county Sites and Monuments Records (SMRs) are now computerised to a greater or lesser extent. The value of these SMRs as repositories of the national archaeological record is considerable and they provide a rich resource for any analysis of the cultural landscape. Many SMRs are now reaching the end of the initial data collection and early computerisation phase. In this paper we review the current nature and status of SMRs and consider the implications for users, actual and potential, which have arisen from the present structure of SMR database design. In addition we discuss the emergence of new technology, Geographic Information Systems (GIS), which is now sufficiently developed to be particularly suited to possible further phases of SMR development. This technology provides a fully integrated spatial database management and analysis environment which would enable SMRs to go beyond the present limiting inventorying stage and provide a highly sophisticated information system. Such a system would be capable of greatly improved functionality, have advanced analysis capability, and be able to develop decision support roles in the management of the cultural environment. These technological advances necessitate the inclusion of the full archaeological record, including its spatial component, within the database environment. The underlying basis of SMR computerisation was formulated under the financial and technological exigencies of the late 1970s and early 1980s. The present structure of computerised SMRs must be seen in the context of these origins. These factors have resulted in the construction of databases which closely mirror the structure of earlier manual card index systems. Thus the database can be searched for archaeological sites and artefacts according to a combination of single or multiple attributes based on boolean logic and standard database interrogative procedures. One major difficulty which has arisen from the general adoption of the standardised database structure mainly promulgated by English Heritage, however, has been the problem of how to handle the locational and geographical information associated with the archaeological record. While all would accept that without knowing where an archaeological site or artefact exists on the ground the value of the information is greatly diminished, in most SMRs the spatial description of the phenomena has been reduced to either a single Ordnance Survey point coordinate or to a nominal representation such as the parish administrative area. In many instances of course the inability to locate a find or site accurately on the ground invalidates the allocation of precise coordinates. No amount of sophistication in information retrieval system design will easily overcome the problems associated with the lack of information precision, though research within the field of GIS concerned with 'fuzzy space' may provide one very profitable avenue of enquiry. In nearly all SMRs the inability to incorporate the full spatial description of an archaeological record within the computerised database has resulted in the information having to be stored by hand on small scale Ordnance Survey topographic map sheets. In this paper our concern is focused primarily upon the handling of the full archaeological record within the computerised SMR. To a considerable extent the way in which the spatial description of an archaeological record is currently handled greatly constrains the effectiveness and utility of the SMR to service the needs of users. To this end three aspects of the handling of archaeological information within current computerised SMRs are considered in the light of the current inability of SMRs to maximise their full potential as they are presently structured; in the light of professional and societal trends toward more sophisticated uses of computerised information systems; in the light of current developments in Geographic Information Systems; and in the light of recent government enquiries and reports into the handling of spatial information and the role of GIS technology in many areas of UK society. The first concern arising from the structure of current SMR databases is that a vital component of the archaeological record, its spatial description, is reduced to a geometric form that in many instances clearly does not reflect reality. Thus linear features, such as embankments or ditches, and zonal areas, such as field systems, are simplistically recorded in the computerised database by the allocation of a single coordinate or a parish unit. It is usual for the coordinate to reflect the centroid of a structure. Some SMRs have attempted to describe the shape of such features with a series of grid references, using three for a linear feature for example. While this obviously contains added information it remains incapable of serious analysis. The implications of this, and other, database restrictions are discussed later. The second concern is that current SMR systems are unable to record the topological relationships which exist between archaeological, natural and human environmental phenomena. This rather technical aspect is also discussed later in the paper but the outcome of this omission is critical because it precludes any form of spatially oriented enquiry or spatial analysis being undertaken on the archaeological information within the database, other than that at a very elementary and crude level. This is especially relevant to the SMR user community for even basic requests for information concerning what archaeological sites exist within a certain distance of a proposed development, or seeking the relationships which