Vector and Raster Structures in Generating Drainage-Divide Networks from Digital Terrain Models

Geographical Information Systems (GIS) are becoming a fundamental tool in many spatial data applications, such as land planning and natural hazards assessment. A procedure for generating and handling hydrological basins data was developed, based on a set of modules integrated with a commercial GIS. The GIS and the other software modules make a complete system for processing the spatial entities and their attributes. Several types of spatial data are involved: elevation data, digitized polygons, which represent land attributes, and automatically generated drainage-divide networks and watersheds. The paper brings spatial data representation into focus and highlights the need for efficient and versatile conversion tools between raster and vector representations, in order to free users to handle their spatial data in different formats.