LiDAR and SLOSH updates Light Detection and Ranging

Transcription

1 LiDAR and SLOSH updates Light Detection and Ranging Richard Butgereit id Information Management Section Head Florida Division of Emergency Management What is Light Detection and Ranging? A sensor is moved over a surface transmitting laser pulses. Range to an object is determined by measuring the time delay between transmission and detection of reflected pulse. In our case, airborne laser swath mapping was conducted to cover large areas of the state. High-precision GPS aboard the aircraft and ground stations confirm position of the aircraft and sensor. 1

2 Results of LiDAR Collection Mass points - billions of records, each a point with X,Y,Z (Longitude, Latitude, and Elevation) as well as intensity. Grids, contours, breaklines intensity images, and digital elevation models may be produced from the mass points. A digital elevation model - or DEM is a digital representation of ground surface topograhy or terrain. Digital Elevation Models 4 2

3 Introduction to the SLOSH Update Process CONTRACTORS & FDEM NOAA MDL & NHC Light Detection and Ranging LiDAR Analyses Vulnerability Behavioral Demographics Transportation Data Processing Development for SLOSH Regional Evacuation Studies Sea, Lake, Overland Surge from Hurricanes SLOSH Models Storm Surge Zones Regional Planning Councils Regional Planning Councils 3

4 CONTRACTORS & FDEM NOAA MDL & NHC Light Detection and Ranging LiDAR Data Processing Development for SLOSH Sea, Lake, Overland Surge from Hurricanes SLOSH Models Regional Evacuation Studies Storm Surge Zones Regional Planning Councils 4

5 Given a SLOSH Basin, which is a geographical region with known values of topography and bathymetry, and a hurricane track (identified by its pressure, radius of maximum winds, location, direction, and speed), the SLOSH model solves a complex set of equations and outputs data by storm category for each individual grid segments. 5

6 Now let s concentrate on the right-hand side of the SLOSH inputs, topography and bathymetry. A Comparison Between the Model Run and Model Base 6

7 Let s look at several adjacent cells Lets say a hurricane makes landfall with a storm tide of 8 feet NGVD 15 DRY Mother-in-Law s house! 10 Pelicer Creek Avg Elev 12 NGVD Cell avg water depth DRY Avg Elev 7 NGVD Cell avg water depth 1 Avg Elev 4 NGVD Cell avg water depth 4 5 I-95 NGVD Now what if we quarter the size of the cells? Lets say the same hurricane makes landfall with a storm tide of 8 feet NGVD 15 DRY DRY DRY Mother-in-Law s house! Pelicer Creek I-95 NGVD

8 Preparation of LIDAR During the initial step in the process, LIDAR data is collected prepared for processing into digital elevation models. 8

9 SLOSH Basins updated During the next steps in the process, digital elevation models produced from the LiDAR are used as inputs for SLOSH grids. 9

10 GIS vs. SLOSH a Matter of Scale 10

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12 SLOSH Model Runs During the next steps in the process, the National Hurricane Center runs the SLOSH model for each basin. 12

13 SLOSH to storm surge zones During the next steps in the process, the RPCs run another model with the SLOSH outputs and high resolution digital elevation models to produce storm surge zones. 13

14 This is the result of the postprocessing stage where only contiguous surge zones from the sea are kept. These zones are combined into a layer that has categories 1-5. Typical Storm Tide Atlas Page The final surge model output is mapped in this way to show the inundation of each category storm. 14

15 Results Let s look at some results New Surge Zones 30 15

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17 This is a case, generally where older surge covers less inland areas Where the new surge goes further inland 17

18 This is not always the case, as in many areas of Pinellas County the newer surge Cat 1 (CHHA) covers less area. As you can see here. 18

19 SWFRPC 2001 Surge Zones SWFRPC Surge Zones

20 LiDAR Projects Legend FDEM Coastal Project Partnering Agencies FEMA HHD Other Compatible Data (Counties & WMD's) NWFWMD LiDAR Distribution 20

21 Other uses of LiDAR Flood Hazard Analysis Fuel Models for Wildland Fire Erosion Sinkholes Aquifer Vulnerability Transportation Modeling Environmental Restoration Archeological Research and Protection Site Planning/Construction ti 21