Upper level ontology and integration assessment modeling in digital watershed

With urbanization and environmental changes, water resources safety such as flood risk and drought have been faced with more challenges than ever before. Integrated assessment and modeling methods provided an effective resolution approach for this problem. However, different geographic data sources and modeling methods have produced barriers for sharing, integration, and communication in integrated assessment modeling. Ontology as a formalized description of domain knowledge provided the sharing conception and terms for watershed assessment and modeling. This paper first discusses ontology in digital watershed modeling. An ontology framework of digital watershed is given based on earth and environmental terminology ontologies (SWEET) and Web ontology language (OWL) representation. Then, the ontologies for integrated watershed flood risk assessment were designed. Ontology-guided watershed flood risk assessment workflow was developed, including cause factor and feature selection, criteria definition, and indicator assessment. Based on digital watershed ontology, entity data schema and field data schema were derived. Finally, an integrated assessment framework of digital watershed was developed, including data sources and GIS tools, watershed integrated assessment ontologies, integrated assessment fusion methods, and assessment database.