Modeling a knowledge-based geographic information system for landscape sustainability: Siberut Island, Indonesia

Tropical oceanic islands because of their small size and isolated nature are characterized by richness in endemic plants and animals. Unfortunately, their endemic biota are highly vulnerable to mass extinction when humans continuously and extensively modify the natural landscapes and ecosystems of such islands. This situation suggests that ecological quality of a small isolated island will continuously decline when humans continue to modify the island's landscape. Therefore, a spatial optimization model based on landscape sustainability principles is required to prevent mass extinction of endemic biota of small isolated tropical islands and to allow human communities on the islands to continuously utilize the island landscapes for their well-being.; This dissertation developed such a model in the form of a GIS knowledge-based model by integrating three concepts: expert system, GIS, and landscape ecology. The development of the GIS knowledge-base model was accomplished through the achievements of three sub-objectives: develop a conceptual model of human - land use - landscape (HLUL) system of Siberut Island; develop a GIS knowledge-base model of sustainable landscape based on the HLUL conceptual model; and evaluate the hierarchical effect of spatial scale to the applicability of the GIS knowledge-based model. The GIS knowledge-base modeling was implemented in ARC-INFO{dollar}spcircler{dollar} GIS software by transforming the heuristic rules of the HLUL conceptual model into GIS programs that utilize record selection and attribute query as well as overlay commands.; An evaluation of the results of implementing the GIS knowledge-base model for generating an optimal combination of land uses and natural ecosystems of Siberut Island revealed that the island is currently in a sustainable stage and will continue in this sustainable stage for 50 years. The evaluation also revealed that the optimal configuration of land uses and natural ecosystems will not support the sustainability of the island landscape within the next 50 years. A further evaluation of the effect of hierarchical spatial scale on landscape sustainability revealed that the island's individual watersheds are not the smallest spatial units that support the implementation of planning and managing the optimized configuration of land uses and natural ecosystems.