January 25, 2008
Written Exercise 1
GIS on the Internet
Project: Identify Helicopter Landing Zones in Wake of Hurricane Katrina
Having reviewed the suggested websites for this assignment and scanned many projects related to disaster relief, I decided to search the Internet for GIS work conducted after Hurricane Katrina. I wondered how GIS might have been helpful in the relief efforts. The environmental and social aftermath of the hurricane seemed like fertile ground for GIS work.
One such project was described on ArcNews Online, in which GIS was used to identify helicopter landing zones (HLZ) along the post-hurricane coast in order to provide aid to victims in 2005. The U.S. Northern Command (NORTHCOM) recruited the U.S. Army Space and Missile Defense Command/U.S. Army Forces Strategic Command (SMDC/ARSTRAT) Measurement and Signature Intelligence/Advanced Geospatial Intelligence (MASINT/AGI) Node, located at Peterson Air Force Base, Colorado, to develop the HLZ maps.
The development of the HLZ maps were crucial to response efforts, because helicopters could arrive quickly to hard-to-reach areas that needed immediate help, but they needed safe places to land in the wake of massive flooding. The HLZ maps used satellite data and preexisting datasets to identify landing zones that incorporated the following criteria: grassland and sparsely vegetated area; current flooded and saturated areas; slope less than 15%; and vertical obstructions such as towers and power lines to be avoided. Layered on top of each other, these features would enable helicopter pilots to identify landing zones. The HLZ mapping project represented the coastal Mississippi region.
Two software packages were used to create the maps: ArcView was used to analyze raster and vector datasets and produce the final map; and ITT Visual Information Solutions ENVI 4.1 was used to analyze newly collected satellite imagery. The goal of the project was to quickly provide pilots with easy and readable maps that would guide them to safe landing zones during the relief effort. The final map had the following layers: the hillshade was placed as a backdrop for topographic rendering, followed by the potential HLZ land classes that met the slope criteria; overlaid on this was street, city, and vertical obstruction data. The US Army teams were able to produce maps within hours. Once the maps were complete, NORTHCOM disseminated the up-to-date maps to recovery teams.
This project is exciting, especially in light of today's class discussion about the tediously slow pace at which maps were previously created. The speed and comprehensiveness of the GIS mapping capabilities are particularly well suited to such crisis situations, in which up-to-date information about the surface of the earth is a matter of life and death. With this type of technology at our fingertips, it is a shame that the greater post-Katrina response effort was not handled with an equally speedy and advanced methodology.