Research On Building Semantically Enriched Geographic Information Services For Land Suitability Evaluation

Land suitability evaluation is one of the main parts of general land use planning,furthermore, it is the fundamental basis for working out land use planning scientifically and land use decision-making.Owing to the process of the evaluation covering multi-discipline and multi-field, various experiential knowledge is needed to help complete comprehensive judgment towards land suitability under the interaction of multi-objectives and multi-rules.With the development of GIS web services,an ever increasing number of suppliers will release their own GIS web services to the Internet and thus provide rich geo-spatial information resources with consumers.How to make full use of the existing experiential knowledge and a wide range of geo-spatial data services and function services is the important basis of scientific and effective evaluation.Semantics-enhanced geographic information web service composition is the key to meet the business requirement of users by taking full advantage of geographic information web services and realize services discovery,composition and invocation.So the main task of research is to solve the problem about how to match the process of evaluation with the corresponding service instances by using semantic technology,making all kinds of services closely combined with the business process until the business process is completed.The paper proposes a work-flow oriented service composition method for land suitability evaluation through the combination of land suitability evaluation method,geospatial information service and web services discovery and composition based on semantic web technology.In this method,semantic description logic is established for the association rules among existing geospatial information services in order to realize services discovery,composition and invocation.Method of group decision making based on analytic hierarchy process combined with domain ontology is used to evaluate land suitability,which realizes the acquisition of reference rules.Through the combination of OWL described ontology and reference rules, implicit knowledge and semantic relationship between the concepts can be deduced from ontology for land suitability evaluation.Ontology concept and geo-data services involving in land suitability evaluation services are described by using OWL-S so as to enhance the semantic information of WSDL,which establishes a sound foundation for the combination of geographic information web service(especially the formation of service chain).A case study is selected as land suitability evaluation for corn growing area in Hebi.Based on the research of workflow engine which supports BPEL4 WS and the characteristics of chain service,data services and function services, in accordance with OGC WMS,WPS,which are distributed in the Web environment and relevant to the evaluation process will be combined to a chain of service.And the chain is exactly service for land suitability evaluation which is customized solutions.