In this week's module, we again analyzed the after-effects of Hurricane Sandy on the coast of New Jersey. However, this week we zoomed in to focus more on structural damage to each parcel. We analyzed the parcels in a selected study area and then used this analysis to determine the probability of a similar outcome in nearby areas.
I examined the damage to each parcel row by row, I started with the parcel in the Northeastern corner of the study area and snaked my way down the street moving from east to west and back. I used a scale of 1:455 when doing my analysis. This scale let me see the damage and debris in each parcel and compare it to the neighboring parcels. Determining wind damage was most difficult. I used debris build-up in each parcel to determine how bad the wind damage may have been. However, by only being able to see the roof of each structure, it was hard to know for certain how severe the wind damage had been. It was easiest to determine inundation, the evidence of erosion and washout was prevalent in each parcel. In our analysis, we noted which structures suffered major damage or were destroyed. With this being a coastal study, we could also look at how many structures were left standing (albeit destroyed), and how many structures washed away from their foundation entirely. I think this information could help with future planning to know which lots were the most vulnerable and suffered the absolute worst damage.
Next, we needed to determine structural damage relative to the coastline. I created a new Coastline feature class and drew a polyline along the ocean shoreline of the Pre_Sandy Raster. I used the Multiple Ring Buffer analysis tool to create a three-ring buffer around the polyline in increments of 100m, 200m, and 300m. I set the symbology to different shaded of transparent blue so I could still see the raster and parcel lines beneath the buffer. After I created the buffer, I used the Select by Attribute tool to select each damage category in the Structure Damage feature class (no damage, affected, etc). I exported the selected data for each category to a new feature class (right click>Data>Export Features). Then, I used the Spatial Join tool with the buffer polygon for each new individual Structure Damage layer. I referenced the attribute table for each new join layer I created to complete the Structure Damage table.
Based on my analysis, every home within a 100-meter buffer of the coastline was destroyed. Alternatively, industrial properties that were 300 meters from the coastline look to have fared relatively well during Hurricane Sandy. I think that the results of my analysis are definitive enough that it would be reliable to assume that in nearby areas 100% of the residential structures within 100 meters of the coastline will suffer major damage or be destroyed. Comparatively, nearby structures within the 200-meter buffer are 91.3% likely to be affected by the same level of damage, and structures within the 300-meter buffer are 34.2% likely to be majorly damaged or destroyed.
Link to Story Map - Hurricane Sandy: Coastal Flooding & Damage Analysis: https://arcg.is/9yTmG
Wow honey! Amazing project! So proud of you!
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