Sig En America

Computers, Environment and Urban Systems 26 (2002) 89–112 www.elsevier.com/locate/compenvurbsys

Expert systems and GIS: an application of land suitability evaluation
S. Kalogiroua,*
a

Department of Geography, University of Newcastle, Daysh Building, Newcastle Upon Tyne, NE1 7RU, UK Accepted 13 September 2001

Abstract In this paper expert systems and geographical information systemstechnologies are combined to help with an implementation of a land suitability evaluation model. The result is the LEIGIS software, which allows empirical work within the framework of this paper. The model used is based on the FAO land classification for crops, and data which describe an agricultural area in terms of soil mechanics and environment. The land evaluation has two parts; the physicalevaluation and the economic evaluation. For the physical evaluation of the land, data for 17 land characteristics have been used and a Boolean classification method has been applied. The implementation includes models for general cultivation and five (wheat, barley, maize, seed cotton, sugar beet) specific crops. A new interpolation function is introduced to map values to scores in terms of landcharacteristics. The economic evaluation includes income-maximization taking into account market restrictions. The expert system has been designed to help with the evaluation of land and to allow alteration in its rules based on different performance observed in local areas. The GIS functions help in managing the spatial data and visualizing the results. The software developed allows the evaluation andpresentation of any equivalent spatial dataset and does not require special computer skills. # 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Physical and Economic land evaluation; Expert Systems in Agriculture; Custom GIS

1. Introduction The problem of selecting the correct land for the cultivation of a certain agriculture product is a long-standing and mainly empirical issue. Althoughmany researchers, organizations, institutes and governments have tried to provide a framework for optimal agricultural land use, it is suspected that much agricultural land is used at below its optimal capability. The increased need for food production
* Tel.: +44-191-222-6359; fax: +44-191-222-5421. E-mail address: stamatis.kalogirou@ncl.ac.uk (S. Kalogirou). 0198-9715/02/$ - see front matter #2002 Elsevier Science Ltd. All rights reserved. PII: S0198-9715(01)00031-X

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S. Kalogirou / Comput., Environ. and Urban Systems 26 (2002) 89–112

and the shortage of resources stimulate a need for sophisticated methods of land evaluation to aid decision makers in their role to both preserve highly suitable lands and satisfy producers’ demand for increased profit. This paper presents amethodology for the physical evaluation of the land based on the FAO’s (1976) framework. It introduces a rather simplistic economic evaluation using the results of a physical evaluation and information on crop yields. The methodology is applied using a piece of specially written software that incorporates expert system and GIS components. The area of interest is agricultural land in CentralMacedonia, Greece. The information concerning yields and prices has been available for 1995 from FAO Statistics for Agriculture (FAO, 2001). The main aim of this paper is to illustrate how important it is for rural planners to provide the methodology for physical land evaluation along with economic evaluation, and to motivate further research on the latter. The initial aim of this research is to providethe geographic society with a stand-alone, powerful and user-friendly application for land use assessment that has customized capabilities and functionalities. However, the focus of the paper is on discussing a method for economic as well as physical evaluation of the land. It aims also to link the theory with the real world. Thus, it provides empirical work based on the results of the land...