Watershed and Stream Network Delineation – Geomorphological Considerations
Geographic Information Systems - Purdue Universityabe325/week.8/Geographic...Run Watershed...
Transcript of Geographic Information Systems - Purdue Universityabe325/week.8/Geographic...Run Watershed...
Geographic Information Systems
What is GIS
How is it used
What are some sample applications
GIS… a definition:
Think of this as a map – database combination.Designed to ask questions that are answered with spatial informationAsk the map and the answer lights-up in the database.Ask the database and the answer lights-up on the map.
You have already used a GIS
If you have used MapQuest or similar sites for an address or driving instructions.
If you have searched online for an ATM banking machine location.
How is it used?
Creation of maps (visualizing spatial relationships)
Beyond maps- shows dynamic relationships
Front-end to databaseAnswers questions like “where is” and “what is nearest…”
Front-end to interactive modelsNow we see “what-if” answered in a spatial way
This web page asks “where is the nearest ATM from a specified point, and how do I get from here to there…
How is it used? Example 1
This website allows access to a county GIS department
Example 2
Example 3
This website displays traffic problems in the context of the street network.
Example 4 Arcview 3 D
A common product is a simple map like this.
Many GIS programs can go from flat map to 3D.
ArcView can easily make a 3D version of the map on the previous slide.
This shows use zone (commercial versus residential) in color and buildings extruded
Answer to query lights-up on map
See a short video of thishttp://pasture.ecn.purdue.edu/~tgis/images/howgiswrk.avi
Example query
GIS is used for maps–but offers more power than mapping software.
A common product is a simple map like this.
ArcMap for display and analysis
ArcToolbox for data preparation
ArcCatalog for data browsing
GIS – visualizing beyond maps
Another typical GIS application – a model output created from many layers.
Animation of air quality change over 7 days time – from a GIS
GIS - Visualizing beyond maps
GIS – analysis and visualizing
CAAGIS is distributing digital aerial photos for all of Indiana
Interactive (and on-line) databases
User-friendly database query (through maps)
Many tools to get online fairly easily
Distribution by INTRA-NET is possible
This site is a local government ( county with 100,000 people) GIS effort. The citizens need to get GIS data for permits to build homes or dig wells and septic tanks. Photos and map layers are available, tied to street address.
Interactive front-end to models
Greatly speeds use
Much wider clientele
You won’t lose the documentation
This is a new and growing use of GIS. It saves the model user much time formerly spent making data layers fit the format required by the model.
Interactive (and on-line) models-
LTHIA (Long Term Hydrologic Impact Analysis)
This model needs many inputs: soils, zoning, weather.
The mapserver-based website allows the user to select a location and have the GIS fetch all the pertinent layers, parameterizing them for the LTHIA model.
http://pasture.ecn.purdue.edu/~watergen/
Watershed Management Decision Support Using Web-Based Hydrological Tools and GIS
Bernard A. EngelJin-Yong ChoiLarry Theller
Agricultural and Biological DepartmentPurdue University
Processes for Hydrologic Impact Analysis Using Web-GIS Tools
Outlet Point Selection Using Web-GIS
Run Watershed Delineation
Watershed Delineation Result
Reflect Land Use Change Using Online Digitizing
Run L-THIA
Runoff and NPS Output/Impact Evaluation
Starting Page
Select Outlet Point Main Menu
Layer ControlOn/Off
Map Display
Display ControlZoom in/outPan, Full extent
Auxiliary functions
Reference Map
WD Submit Button
Watershed Delineation and Result Page
Results Display
Print and Download Page
L-THIA Input Data Preparation about Present Land Use and Hydrologic Soil Group
Buttons for Online Tool
Change Land Use in the Watershed Delineated Using Online Digitizing Tool
Add Low Density Residential, Commercial, and High Density Residential Areas
Results Page after Merging the Land Use Change
Present Land Use Data
Proposed Land Use Data
Application Buttons forHydrological Model Operation
L-THIA Input Page After Changing Land Use
Input is created for the second scenario
L-THIA Result Runoff Tables
Comparison Chart to evaluate the impact on hydrology of the proposed landusechange.
Runoff Landuse
NPS Pollutant Loading Chart
LTHIA and WD training
We created an 8 minute video which steps you through the WD and LTHIA process.
You will see this in lab, and you can view it here: http://
pasture.ecn.purdue.edu/~theller/abe325/wd_lthia_new.avi