GIS Applications Module 5

This week we learned how to carry out activities related to coastal flooding. We used Digital Elevation Models (DEM) derived from various sources to map out the effects of storm events. In the first exercise for this module we looked at data from New Jersey associated with Hurricane Sandy. We had to work with LAS datasets and rasters to carry out our evaluations. We had to do conversions using the TIN to Raster tool and we also had to use the Raster Calculator to be able and distinguish differences in raster datasets over time. Once we had all or our data converted and ready to use we were able to map areas where changes in altitude occurred due to either deposition or removal of material by forces created by Sandy. Below is a map I created that shows areas where material was either added or removed by storm activity. 

The second part of the this weeks module continued with the same theme however we moved the study area to the State of Florida and mapped potential storm surge zones and impacts to buildings. We were provided two DEM's one derived from LIDAR data and the other was a conventional USGS DEM. We first had to ensure the units of both DEM's were the same so we had to use the Times tool to change units. We had to reclassify values in the DEM's to represent areas that were flooded (below 1 meter) or not flooded. Rasters were converted to polygon using the Raster to Polygon tool. Once we had derived polygons we spatially joined the DEM derived polygon with a shapefile containing buildings in the study area. The spatial join allowed us to see what buildings were impacted by the predicted storm surge. A series of selections by attribute were used to carry out queries that specified the impacts by building type and DEM type. Once all the analysis was complete we put together a map showing the predicted storm surges derived from each DEM and the potential impacts to buildings. Below is the resulting map from this exercise.