Simple Data Types Point (2d or 3d) –Coordinates with attributes Polyline (2d or 3d) –Points collected by line segments –2 lines max per point Polygon (2d) –Closed polylines Rasters (2d, 3d elevations) –Points in a grid (one attribute or lookup) Triangulated Irregular Networks (2d or 3d) –3 lines max per point

Triangulated Irregular Networks TINs A “mesh” of triangles Vertices Nodes Edges, Line Segments, Links Arcs

TINs – Complex but Flexible

Water Resource Management Improving Environmental Site Management Through the Use of Internet Resources Authors: Gary Whitton, Clayton Cranor, Michael Lilly, David Nyman

More Complex Data Types Networks –Related polylines and/or TINs Raster Mosaics –Overlapping rasters Spatial Databases/Datasets –All types and relationships Object Models

Object Data Models “Objects” are things Objects are connected through “relationships” “Methods” are behaviors of objects Address Number Spatial Data Street Name Spatial Data

Terminology Arc Desktop GeoDBObject model DatabaseDisk LayersFeature Dataset -DatabaseProject Folder LayerFeature Class -Table or portion File Feature ObjectRecord- AttributeFieldPropertyField- Shapefile Type Feature ClassType ClassGeometry type in field -

Additional Slides

Networks Streams and rivers –Water supply –Flood prediction –National Hydrology Network Transportation (mature): –Freeways, highways, and roads –Ships –Planes Disease vectors (developing) Natural Resource Management (new)

Network Analysis Vertex: Sum of inputs and outputs = 0 Edge: Has maximum capacity Source: Inputs to network Sink: Outputs from the network

Global Water Cycle

Complex Features Polyline –Rivers & Streams: Connected networks of “reaches” –Attributes include: quantity of flow Polygons –Groups of islands: Hawaii –“Holes”: Lakes on surfaces Islands on lakes