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Introduction to GIS Watershed Discretization (model elements) + Digital Elevation Model (DEM) Geographic Information System Intersect model elements with Soil Land Cover Rain Results Geographic Information System A spatially referenced database for storing, retrieving, transforming and displaying information Hammer A tool meant to deliver an impact to an object. Components of Geographic Database Input Database GEOGRAPHIC DATABASE Query input Attributes Topology Position Management Systems Retrieval Transformation Data Input Existing maps Interactive terminal Field observation Digitizer Text file INPUT DATA Sensors Scanner Magnetic media Data Output Displaying and Reporting Visual Display Terminal MAPS Printer Plotter TABLES Magnetic Media FIGURES Data Types Cells, Pixels Points, Lines, Polygons Geographic Information Systems Basic Concepts PC/Workstation Topography Roads Soil Map Land cover Color IR Manual encoding Coordinate digitizer Data Graphics/color printer output image manipulation Monitor Plotter CD Hard Disk Video or array scanner Drum or laser scanner Data Input Floppy disk Data storage Film recorder Data output Hydrologic Modeling Data Model based on Inventory of Data layers (GIS) Data Model Based on Behavior “Follow a drop of water from where it falls on the land, to the stream, and all the way to the ocean.” R.M. Hirsch, USGS Integration of GIS and WQ/Hydrologic models Ad-hoc (loose) integration Operating system1 GIS User File Exchange Interface Operating system2 Process Models User Integration of GIS and WQ/Hydrologic models Partial (close) integration Operating system 1 GIS File Exchange Interface User Operating system 2 Process Models Integration of GIS and WQ/Hydrologic models Complete integration (modeling within GIS) Common operating system GIS Pre-processor Process Models Post-processor Interactive User Interface User (adopted from Tim and Jolly, 1994) Disadvantage of Complete Integration (modeling within GIS) The GIS software are not designed for Water Quality/Hydrologic modeling. Difficult to perform complex mathematical computation processes Longer data processing time (computational time) GIS Functions • Edit –Topology • Build feature • Drop feature • Create label • Centroid label • Renumber node • Coordinates – Transform – Project – Define Projection • Convert • Map sheet – Append – Clip – Map join – Split GIS Functions • Analysis – Overlay • Identity • Intersect • Union – Proximity • • • • • Buffer Buffer region Near Point distance Theissen – Update • Erase • Update – Extract • Clip • Select – Merge • Append • Dissolve • Eliminate GIS Functions – Conversion • Poly to region • Arc to region • Union • Geocoding • Grid: – data conversion • Image – Georectification • TIN • Measurements • Cut-fill • Volume – Analysis • • • • Contour Profile Line of site Visibility GIS Functions • Tables – Info Item – Table summery – External DBMS Open Source GIS • Free • Secure: no supplier dependence • Encourages involvement and sense of ownership; internationalization • Support network via internet • High quality • Good maintenance • Open standards; interoperability MapWindow GIS • MapWindow GIS •MapWindow GIS is an open source GIS (mapping) application and set of programmable mapping components. Because it is distributed as an open source application under the Mozilla Public License distribution license, MapWindow GIS can be reprogrammed to perform different or more specialized tasks. There are also plug-ins available to expand compatibility and functionality. MapWindow GIS is built upon Microsoft .NET technology but is not a multi-platform application and hence does not run on non-Microsoft operating systems including Mac OS X, Linux, and UNIX. MapWindow Innovation D8 Algorithm Flow in 1 of 8 preset directions D∞ Algorithm Flow partitioned into up to 2 directions based on steepest slope on each of 8 facets