Design And Development Of The Expert System For Forest Lands' Classification And Evaluation

Recently,Expert System(ES for short) has been widely ultilized in every field by reason of its particular advantages. The system uses the abundant expert knowledge stroed in Knowledge Base combining the reasoning abilities of Inference Engine and Interpreter to simulate the decision process of human experts and solve complicated problems in relative fields.Owing to forest lands'transfer load have been enhanced increasingly since reforming the system of collective forest rights,deveplop forest lands' clssification and evaluation ES to be propitious to assist or.replace in a certain extent forestry expert to doing forest lands'classification and evaluation.In this study, Changzhutan District, Hunan Province as the research object forest land, take the case of Xingsha Town Changsha County forest land, apply ES's knowledge and theory in forest resource's classification and evaluation. The system sets forest lands'site quality factors (topography, soil type, soil thickness, humus layer thickness, height, slope aspect, slope position, slope) and the ecological and economic quality factors (community structure, land cover, species diversity, business level, logging conditions, human interference, supply potential, transport distance) as the main parameter for the forest lands' classification;and also can set the scope of the evaluation, selecting the evaluation method, at last,finish scientific, rational evaluation.To enhance the usefulness of the ES, this system realizes the knowledge base of forest lands'classification & evaluation and inference engine separation. Users can flexibly define expert system inference engine, namely:the forest land for different situations, users can customize the inference rule, and choose the most appropriate evaluation method to finish forest lands'classification and evaluation of forest resources.Using Arcgis Engine components provided by ESRI U.S., the use of ActiveX component-based development techniques to achieve the results of expert system classification and grading of the hook with ArcEngine graphics library; at the same time, the system also enables editing layer elements, spatial analysis and management functions, and can add highways, rivers, forest lands'and other surface materials flexibly, develop the measurement capabilities of distance, length and area, which greatly expands the flexibility of spatial data management, but also enhanced the results of classification and evaluation of the visual capabilities, so that the results of forest lands'classification and evaluation inquiries are rich and varied, simple and practical.Through collecting and arranging the experts'knowledge, forest classification formula library (Formula.dll) have been built, providing some expert knowledge for other relative systems as well as simplifying the development of the systems related.The system in addition to completing classification and evaluation of forest lands, but also to achieve the project selection, project statistics, regional updates, data updates, rule modification, computing cumulation, database modification and results report and so on, enhance the system's practicality.