OBJECT-ORIENTED MODELING AND GIS INTEGRATION IN A DECISION-SUPPORT SYSTEM FOR THE MANAGEMENT OF EASTERN HEMLOCK LOOPER IN NEWFOUNDLAND

Recently available system design tools were used to explore the re-engineering of pest management models and the computer system frameworks used to deliver these models in order to improve model expansion and to apply them to new problems. These models and frameworks were integrated with software tools to form decision support systems (DSS) for operational use by managers in the field. Modeling of insect management could then be supported by these systems. In a test case, a DSS that modeled the predicted impact of the eastern hemlock looper Lambdina fiscellaria fiscellaria (Gn.) lacked expressiveness and was difficult to modify and apply to new situations. As well, the architecture of the DSS did not promote reusability and extensibility of the code. To help solve these problems, the insect application was redesigned in an object-oriented (OO) structure. Analysis and design was supported by the OMTool software. The design was then prototyped in the ProKappa system development environment to determine the effectiveness of the design. The OO paradigm provided a new approach to rebuild the models based on natural, hence more stable, abstractions rather than artificial ones contrived to suit computer processing, which is the situation normally encountered with traditional, procedural styles of programming. The flexible structure of the design enabled easier construction of new applications in the pest management domain.