GIS 4930: Special Topics - Week 2: Analyze

After creating a basemap of the study area and determining the potential flood zones, an evacuation route map was created based on four different scenarios.  Using the Network Analyst toolbar in ArcMap, I was able to define optimal evacuation routes to allow the transfer of patients from one hospital to another, deliver emergency supplies to shelters, transfer citizens to the nearest shelter location, and finding the nearest shelter for local residents.

The first scenario mentioned is the evacuation of patients from Tampa General Hospital on Davis Islands.  The hospital is located at the northern tip of Davis Islands, a small, residential area that was created with sediments dredged during the creation of the nearby canals.  Due to the very low elevation of the islands, the hospital will almost certainly be subjected to heavy flooding during the coming storm.  A route was created to evacuate all patients to other local hospitals before the hurricane hits.  The hospitals that were chosen to accept patients is the Memorial Hospital of Tampa and the St. Joseph’s Hospital.  These two routes were created by using the Network Analyst toolbar and ensuring that the Impedance was set to Seconds for calculating the routes.

The second scenario displays the distribution of emergency supplies by the U.S. Army National Guard to three storm shelters.  Emergency supplies will be delivered to the U.S. Army National Guard armory, located at Howard Ave. and Gray St. on the west side of the river.  Once the supplies reach the armory, National Guard troops will be tasked with delivering the supplies to the local storm shelters.  However, the supplies may not reach the armory before the storm hits, so drivers will have to travel to the shelters while avoiding flooded roadways.  Three new routes were created to assist the drivers and the National Guard troops to safely deliver emergency supplies to the shelters (Tampa Bay Blvd, Middleton High School, and Oak Park Elementary).  These routes were created using the same tools used in scenario one. 

The third scenario displays the creation of multiple evacuation routes for downtown Tampa.  Since the downtown area of Tampa is heavily populated, routes were created to assist the general public in evacuating to the nearest shelter location as quickly as possible.  This was accomplished by using the Scaled Cost function, which works by multiplying the Impedance attribute by the Scaled Cost attribute.  A New Closest Facility was created using the Network Analyst toolbar.  Using this, I was able to classify a point layer as Incidents, which shows all of the locations in downtown Tampa that need to be evacuated.  As shown in the map attached, the final destination for all evacuation routes is the Middleton High School shelter.

The fourth, and final, scenario shows residents which of the three shelters is closest to them by drive time.  The objective in finding the nearest shelter is to aid residents in getting to their designated shelter as quickly as possible and help alleviate confusion.  This was achieved by creating a New Service Area within the Network Analyst toolbar.  The area surrounding Tampa Bay Blvd Elementary is shown in light green, the area surrounding Middleton High School is shown in light red, and the area surrounding Oak Park Elementary is shown in light yellow.