Module 03
Inundation
Yesterday in the Great Smokies
Webcam archive
Webcam archive
GEO 509: Workshop in Geospatial Technologies
03: Inundation
Goals
Assume that floods have a maximum height above stream and that the floodplain is all adjacent areas below that height.* Using relative elevation models (REM), calculate and visualize potential inundation areas for a given floodplain.Methods overview
- Query for stream in your watershed.
- Correct stream alignment against aerial imagery.
- Sample ground elevations along stream.
- Interpolate elevations to create a relative elevation model.
- Calculate and visualize extent of inundation.
Edit candidate stream
- Stream alignment may not match aerial imagery. Edit stream for best results for analysis.
Task 3
Module downloads
- Tools for task and lab > notebook
REM
- Relative Elevation Model
- Height above river in AOI.
Step 1
- Sample elevations
- along stream at a regular interval, e.g. 40ft.
- That's why are river flowline is so important!
Step 2
- Interpolate Surface
- IDW – Inverse Distance Weighting
- using sampled elevations along river.
- Creates a surface of gradual elevation change.
Step 3
- Subtract REM from DEM, e.g., DEM - REM.
- to find height above river.
Inundation
- Find and symbolize areas that are below a certain height above the river.
- Query REM, e.g., REM < 25.
Animation
- This analysis has complicated output.
- Let's animate it in ArcGIS Pro!