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

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

Web GIS Based Online Watershed Delineation Capability Bernard A. Engel Jin-Yong Choi

Watershed: A basin, drainage or catchment area that is the land area that contributes runoff to an outlet point Outlet point Watershed boundary Rain Runoff What is Watershed

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.

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

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 Outlet point

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

Where to begin?

Display Functions Main Menu Layer Control On/Off Map Display Display Control Zoom in/out Pan, Full extent Auxiliary Functions Reference Map WD Submit Button

Using the SDSS Indian Creek, Tippecanoe County, Indiana Outlet point selected

Results Page Using the SDSS Indian Creek, Tippecanoe County, Indiana

Watershed Delineation: Indian Creek, Tippecanoe County, Indiana Run hydrologic models - Impervious Area - L-THIA - SEDSPEC - Peak Runoff Estimation Results PageResults display

Download and Print Map Using the SDSS Indian Creek, Tippecanoe County, Indiana

On-line Digitizing Tool: Indian 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 On-line Digitizing Tool: Indian 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 On-line Digitizing Tool -> Input Preparation Indian Creek, Tippecanoe County, Indiana

Thank you !