Hazards: Coastal Flooding

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Hazards: Coastal Flooding

GIS 5100 Applications in GIS- Module 4

Learning Objectives: 

  • Become familiar with procedures for coastal flooding assessment
  • Understand how elevation models are used to delineate coastal flood zones
  • Perform overlay analysis in vector and raster domains
  • Examine the effects of differences in boundaries on the outcomes of spa al analysis
  • Determine errors introduced by using coarser quality datasets


Analysis 1: Determining Erosion:

In this analysis, LiDAR data was used to evaluate the change in elevation along a section of the New Jersey coastline from before and after Hurricane Sandy. Digital Elevation models (DEMs) were created to compare the pre and post Sandy elevations. The map below demonstrates the changes. 

Tools Used:

  • LAS Dataset to TIN
  • TIN to Raster
  • Raster Calculator


Analysis 2: Storm Surge in New Jersey


Using a provided DEM the area of flooding was classified and quantified. In the screenshot below the blue area represents areas affected by storm surge(flooded) and the green areas represent non flooded areas for Cape May County, New Jersey. Using that attribute table enabled us to calculate the percentage of Cape May County that were flooded. 

Tools Used:

  • Reclassify
  • Raster to Polygon
  • Calculate Field
  • Basic arithmetic 

Analysis 3: Storm Surge in Florida

The outcome of a storm surge analysis can vary greatly depending on the data used. This analysis compares the uses of USGS high resolution imagery with that of Lidar Data The processing used on each image was identical. The processing used on each of these was identical and assumed 1-meter storm surge. 

Tools Used: 

  • Reclassify
  • Region Group
  • Extract by Attributes
  • Raster to Polygon
  • Attribute table manipulation
    • Add field
    • Calculate field
    • Select by attributes






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