GIS Portfolio: Ross Wygmans

The ability to describe, quantify, and understand spatial data quality is an essential function of all GIS practitioners and professionals. Two of the most common metrics used to describe spatial data quality are accuracy and precision.  The terms accuracy and precision are sometimes used interchangeably. While these metrics of spatial data quality are certainly related, these two terms describe two distinct attributes. Accuracy refers to how close a mapped representation of an object is to the object's actual location, and precision refers to the consistency of a measurement method.  Precision The map below shows 50 waypoints that were collected at a single location using a Garmin GPSMAP 76 unit. The yellow star represents the average waypoint, which is the average XY coordinates of all 50 waypoints. The buffers extending out from the average waypoint represent the 50th, 68th, and 95th percentiles. These areas contain 50, 68, and 95 percent of all the waypoints taken. The most c

As the Earth's climate continues to change, hurricanes and other tropical events are becoming more frequent and more intense. A significant cause of damage associated with these events is linked to storm surge -- an abnormal rise in sea level above the normal tidal level. In the first part of this exercise, we analyzed damage that occurred from Hurricane Sandy along a barrier island off the coast of New Jersey called Mantoloking. Red indicates areas of erosion and blue indicates areas of debris buildup or sand accretion.  In the second part of this exercise, we predicted coastal flooding that would occur due to a 1 meter storm surge using two different digital elevation models (DEMs) -- a high-resolution LiDAR DEM and a regular resolution USGS DEM. We then analyzed the number of buildings that would be impacted based on each of these DEMs. The total number of buildings impacted based on the USGS DEM was nearly twice the amount based on the LiDAR DEM. This significant difference is