LIDAR Flood mapping for Brownsville and Matamoros

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LIDAR Flood mapping for Brownsville and Matamoros

• Gueudet Pierre
• GIS in Water Resources
• University of Texas Austin
• Fall 2002

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Particularity of the region

• Frequent Rainfalls (hurricanes floods)
• Very flat region (5 to 6 m above sea level)
• A vast network for irrigation

Bonsville/Matamoros
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Procedure
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Terrain model processing

• I need to
• ?Collect LIDAR data
• ? Build a Hydro Network
• ?Build a TIN which rivers have a clean
  cross-sections (problem with bridges)

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First Step collecting LIDAR data

• Elevation accuracy 10 to 25 cm
• records first and last returns of individual
  pulses and intensity

Applications in ? Flood mapping ? Forest
management ? Land cover classification ?
Atmospheric pollution monitoring
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First Step collecting LIDAR data

• I dont have the LIDAR data yet (not available
  before
• January) then
• ? I used less precise data (7 m resolution)
  from the Bureau of Economic Geology.
• ? I just obtained LADAR data for a small part
  of Brownsville and I am going to work on it.

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Second step building an Hydro Network

• I tried to use Arc Hydro Terrain Processing. I
  got no useful
• results because of
• ? the flatness of the region
• ? the precision of the data

Flow direction
Streams obtained with Arc Hydro Terrain processing
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Second step building an Hydro Network
gt I am going to work only on the Rio Grande
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Third step terrain processing
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Third step terrain processing
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Third step terrain processing
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Conclusion

• Work in progress!
• I am going to start working on HEC-GeoRas and
  HEC-HMS.
• I want to use the LIDAR data to see if I can
  obtain interesting results with Arc Hydro Terrain
  Processing