GIS4048 - Module 4 - Coastal Flooding

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In this lab, we assessed and modeled coastal flooding risk using LiDAR and DEM data provided to us. The assignment focused on understanding elevation driven flooding, specifically to major events like Hurricane Sandy in New Jersey and an assumed 1 meter storm surge in Collier County, Florida.

We started of with using pre and post Sandy LiDAR datasets of Mantoloking, NJ. After converting .laz files to LAS, I generated TINs and raster DEMs to visualize elevation change and subtracted the storm DEM from the post storm DEM. This revealed where land was lost to erosion and where sand or debris had been deposited. 

Using a provided DEM, I could reclassify the raster to isolate areas at or below 2 meters in elevation, representing areas that has potentially flooded from Hurricane Sandy. After masking the data to the state boundary, I calculated the percent of Cape May County that was impacted and came up with this map below:

Shifting to Florida, I compared two DEMs (LiDAR vs. USGS photogrammetry) to see how elevation source affects flood zone mapping. I created flood zones for each DEM using a 1-meter surge threshold (this took me incredibly way too long to figure out as I was still using the New Jersey Boundary in my Environments), then used spatial joins to determine which buildings were impacted.

Overall I fairly enjoyed this lab. It helped me understand the importance of risk assessment and the use of GIS in Urban planning and flood zoning, while also showing that there could be much much more data that wasn't covered in this to accurately assess future storm and flooding impacts.

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