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Explore how LiDAR technology revolutionizes water resource analysis by providing accurate elevation data and modernizing DEMs for better analysis. Learn about LiDAR data attributes, making DEMs from LiDAR, and the process for evaluating LiDAR data.
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LiDAR and Water Resources Moulay Anwar Sounny Slitine GIS in Water Resources CE 394K - Fall 2007
What is LiDAR ? • Uses Laser and Sensor • Transmit and Receive pulses from reflected surfaces (Earth) • Accurately measures elevation of a point on the earth
Water Resources Today • Uses USGS DEMs • Interpolated from USGS contours • Many Errors • Limited in applications on flat lands (Places that do not have a lot of elevation change)
LiDAR – The Next Generation DEM • Current DEMs are not accurate • LiDAR offers a way to modernize the DEMs • New DEMs will lead to better Water Resource Analysis • LiDAR will also lead to more DEM coverage
What does LiDAR Data look Like? LiDAR data is comprised of 4 attributes X Y Elevation Intensity 1355800.04000000000 1125836.62000000000 549.45000000000 36 1355800.04000000000 1125284.62000000000 534.08000000000 29 1355800.04000000000 1125108.12999999000 532.59000000000 21 1355800.03000000000 1126544.83000000000 564.99000000000 53 1355800.02000000000 1127122.34000000000 563.89000000000 70 1355800.02000000000 1125728.90999999000 546.26000000000 48 1355800.02000000000 1125511.54000000000 534.51000000000 56 1355800.01000000000 1127581.62999999000 561.84000000000 66
Making a DEM from LiDAR A Two “very long” step process 1. Convert the raw tables to point shapefile 2. Interpolate points to a raster using 3D analyst
LiDAR Evaluation Positives • Superior accuracy due to data density that eliminates interpolation. • USGS Contours 1000s of point per county to millions of points with LiDAR • Better Data give better analysis Negatives • Huge Datasets • Time Consuming
Automation • Model Builder • Python • Visual Basic Scripting • ArcCatalog Command Line
Preview of the Paper • Outline of Process and Steps • Explanation of Scripts Used/Made • Utilization of Data with ArcHydro • Applications to Pollution Study on Texas Gulf Coast
LiDAR: Floodplain Mapping NED 30m NED 10 m LiDAR • 3D River-Stream Channel and Floodplain Source: KSU