| Cartographic modeling (also known as map algebra) is a powerful set of operations for manipulating raster geographic data. Zonal operations are one type of cartographic modeling operations where the spatial scopes of the operations are defines by zones. The conventional zonal operations only work with raster data and lack the capability of performing spatiotemporal analysis. This research developed zonal operations for spatiotemporal analysis where spatiotemporal zones can be defined in the vector data model. The zonal operations were used to extract watershed hourly or daily precipitation for use in non-point source pollution models and to explore the effects of antecedent precipitation on water quality samples. The case studies demonstrated the usefulness of the operations. A software tool, NexTool was also developed to process and build NEXRDA precipitation database, which was used in the case studies.;Key words: GIS, cartographic modeling, zonal operation, spatiotemporal analysis, NEXRAD... |
