Introduction to GIS

Watershed Discretization (model elements) + Land Cover Soil Rain Results Intersect model elements with Digital Elevation Model (DEM) Geographic Information System

A spatially referenced database for storing, retrieving, transforming and displaying information Geographic Information System

A tool meant to deliver an impact to an object. Hammer

Query input GEOGRAPHIC DATABASE PositionTopology Attributes Management Systems Transformation Retrieval Input Database Components of Geographic Database

Interactive terminalDigitizerText fileScannerMagnetic media Existing maps Field observationSensors INPUT DATA Data Input

Displaying and Reporting Visual Display Terminal Printer Plotter Magnetic Media MAPSTABLESFIGURES Data Output

Data Types Points, Lines, Polygons Cells, Pixels

manipulation Manual encoding Coordinate digitizer Video or array scanner Drum or laser scanner PC/Workstation CD Hard Disk Floppy disk Soil Map Topography Roads Land cover Monitor Plotter Film recorder Graphics/color printer output ColorIR image Data Input Data storage Data Data output Geographic Information Systems Basic Concepts

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 Operating system2 Process Models Operating system1 GIS File Exchange Interface User Interface User Ad-hoc (loose) integration User Interface User

User Interface Operating system 2 Process Models Operating system 1 GIS File Exchange Interface User Partial (close) integration Integration of GIS and WQ/Hydrologic models

User Complete integration (modeling within GIS) (adopted from Tim and Jolly, 1994) GIS Process Models Pre-processorPost-processor Interactive User Interface Common operating system Integration of GIS and WQ/Hydrologic models

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

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 GIS Functions TIN Measurements Cut-fill Volume – Analysis Contour Profile Line of site Visibility

Tables – Info Item – Table summery – External DBMS GIS Functions

Free Secure: no supplier dependence Encourages involvement and sense of ownership; internationalization Support network via internet High quality Good maintenance Open standards; interoperability Open Source GIS

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.

Flow partitioned into up to 2 directions based on steepest slope on each of 8 facets D ∞ Algorithm D 8 Algorithm Flow in 1 of 8 preset directions MapWindow Innovation