Workshop for Watershed Management Using Web-Based Decision Support Tools

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Workshop for Watershed Management Using Web-Based
Decision Support Tools
Bernard A. Engel Jin-Yong Choi
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Tools

• Web-based Watershed Delineation
• L-THIA Long-Term Hydrologic Impact Assessment
• SEDSPEC Sediment and Erosion Control Planning,
  Design and SPECification Information and Guidance
  Tool

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Web GIS Based Online Watershed Delineation
Capability

• Bernard A. Engel
• Jin-Yong Choi

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What is Watershed

• Watershed A basin, drainage or catchment area
  that is the land area that contributes runoff to
  an outlet point

Watershed boundary
Rain
Runoff
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What is Watershed Delineation

• Watershed Delineation Define the watershed
  boundary based on topographical information about
  an outlet point
• Outlet point A point on a stream or river of
  interest.

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Why we need Watershed Delineation (WD) capability

• Need to understand target area and its features
  that are related with hydrologic phenomena to be
  analyzed at outlet point (e.g. peak runoff)
• Control boundary (watershed) is needed to gather
  hydrologic data including soil, land use, weather
• Watershed delineation is first hydrologic
  analysis step

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Methodology (1)

• Traditional Approach
• Hand drawn on a paper topographic map
• Contour line (Continuous line for the same
  elevation points) use
• Requires experience and labor
• Analogue approach
• Manual

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Methodology (2)

• Using DEM and desktop GIS software
• Digital Elevation Model (DEM) Grid format, Each
  grid has elevation (altitude) value
• GIS Geographic Information System Computer
  program for digital mapping
• Possible automatic data preparation
• WebGIS tools
• WWW GIS Yahoo Map, MapQuest
• Preprocessed data, limited functionalities

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Where to begin?
http//pasture.ecn.purdue.edu/watergen
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Display Functions
Auxiliary Functions
Layer Control On/Off
Map Display
Reference Map
Display Control Zoom in/out Pan, Full extent
WD Submit Button
Main Menu
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Using the SDSSIndian Creek, Tippecanoe County,
Indiana
Outlet point selected
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Results Page
Using the SDSSIndian Creek, Tippecanoe County,
Indiana
http//pasture.ecn.purdue.edu/watergen
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Watershed DelineationIndian Creek, Tippecanoe
County, Indiana
Results Page
Results display

• Run hydrologic models
• Impervious Area
• L-THIA
• SEDSPEC
• Peak Runoff Estimation

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Download and Print Map
Using the SDSSIndian Creek, Tippecanoe County,
Indiana
http//pasture.ecn.purdue.edu/watergen
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On-line Digitizing ToolIndian Creek, Tippecanoe
County, Indiana
Land Use Change Using On-line Digitizing Tool and
Run L-THIA
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On-line Digitizing ToolIndian Creek, Tippecanoe
County, Indiana
Land Use Change Using On-line Digitizing Tool and
Run L-THIA
Land Use Change Report after Digitizing
Land Use Change Using On-line Digitizing Tool
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On-line Digitizing Tool -gt Input
PreparationIndian Creek, Tippecanoe County,
Indiana
Land Use Change Using On-line Digitizing Tool and
Run L-THIA
Land Use Change Report after Digitizing
Scenario 1 Before Change
Scenario 2 After Change
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Thank you !
http//pasture.ecn.purdue.edu/watergen