It started out as just another training exercise.
On March 2, 2002, members of a South African rescue organization were participating in a simulated sea recovery drill in Table Bay, an area northwest of Cape Town, when fog suddenly rolled in, enveloping the three teenagers who had volunteered to act as survivors of an airplane crash. When rescuers were unable to quickly locate the trio, the drill quickly became a real-life emergency.
Just short of 90 minutes later, the three survivors were pulled from the icy Atlantic waters. The incident not only demonstrated the value of a newly developed GIS-based sea search and rescue application but also helped refine its functionality.
The South African Search and Rescue (SASAR) exercise involved personnel from many different organizations including the National Sea Rescue Institute (NSRI), police water wing, the South African Air Force, port authorities, METRO rescue, Cape Town's Maritime Rescue Coordination Center, and several disaster management units for the City of Cape Town. Although the drop locations for the survivors were prearranged, rapidly changing conditions made coordinating these units challenging once the incident evolved into a rescue effort. As part of the exercise-turned-emergency, personnel used RescueView, an ArcView 3.2 application, to identify the last known location of the survivors, track rescue craft, and explain the event to the media.
GIS has become a familiar tool for personnel responding to emergencies on land. A common GIS-based framework makes data maintained by various agencies readily accessible so that timely information can be brought to bear on the developing situation. This framework also centralizes and organizes data for analysis and visually displays critical information during an emergency. Mapping makes complex information instantly comprehensible in a way not possible with text or tables. By giving managers the tools for integrating data from many sources and analyzing how an event will affect an area, GIS has revolutionized emergency response for many agencies.
Kobus Meyer, a member of one of the NSRI stations involved in the Table Bay exercise, wrote RescueView. Developing a sea search and rescue application presented Meyer with some unique challenges. The marine environment is quite literally a fluid one. Currents can carry victims far from the point in which they first enter the water and the rate of their travel (i.e., their drift) can vary considerably. The Table Bay exercise illustrated that the ability to predict the location of a victim in the water would be tremendously useful.
Not only is a victim's location constantly changing but the time it takes to reach a person in the water is critical. According to Meyer, "A minute or two is the difference between yes, you have them or no, you don't. That matter of two minutes is the difference between finding the guy alive."
Meyer has a self-confessed "passion for helping people." He has been involved in volunteer emergency services since 1992 and joined NSRI in 1996. He became a member of a newly founded Station 18 in Melkbosstrand, a small town about 40 kilometers north of Cape Town.
A nonprofit organization staffed entirely by volunteers, NSRI saves hundreds of lives each year. NSRI volunteers, who all earn their livelihoods in other ways, are paged and drop what they are doing to respond to emergencies. In addition to operations, volunteers spend many hours honing the skills required for sea search and rescue.
While any rescue at sea has inherent dangers, conditions off the South African coast can be especially treacherous. Surrounded on three sides by the sea, its 3,000 kilometer-long coastline is swept by two major ocean currents and subject to variable and intense winds, upwelling cells, and large standing waves.
However, miles of beaches and a subtropical climate lure tourists and South Africans alike to the shore to enjoy water sports of all types-kayaking, sailing, swimming, windsurfing, surfing, diving, and snorkeling. In addition to calls generated by swimmers, boaters, and others in distress, NSRI stations must also be prepared to assist survivors of downed jetliners because the adjacent area is a major arrival route for overseas flights landing in Cape Town.
As part of his training for duties at Station 18, Meyer took courses in fire fighting, first aid, radio communications, and off-road driving and serves as a coxswain on NSRI rescue craft. After joining the local disaster management corps, he gained additional experience responding to fires and vehicular accidents. Trained as an emergency medical technician, he is also qualified as a primary member for both private and public ambulance services. He has been involved in numerous rescues as a crew member, mobile land support person, and in the control room.
Despite the best efforts of responders, rescues do not always have happy outcomes and, unfortunately, Meyer has had drowned victims, including some children. "When the opportunity came that I could utilize my knowledge of GIS, coupled to sea rescue and EMT work, I decided to write a sea rescue application that will enable someone to track, control, or estimate where a victim may be," said Meyer.
With 12 years of experience with Esri software in addition to his knowledge of sea rescue, Meyer realized that GIS could supply an intuitive tool for visualizing these types of emergency situations and coordinating aid efforts. When he began designing RescueView, he found an abundance of GIS-based emergency applications but few that dealt with sea rescue.
Writing an application for volunteers who would never have time to become GIS experts applied an additional development constraint. NSRI's limited funds affected the hardware which, in turn, affected the choice of GIS software. An earlier agencywide requirement for electronically filing event reports had meant that all stations did have computers but these machines were not necessarily the newest or most robust. Installing computers onboard was not an option as the rescue craft are open boats and funds for ruggedized devices of any type were not available. What Meyer needed was an application that was simple and inexpensive and easy to operate for nonspecialists.
The result, initially developed in about two weeks, presents users with a pared down interface. All the buttons for RescueView functions are logically grouped and presented in a main dialog box. When an incident is called in, a station staff member creates an operation. To this operation, he adds what is currently known about the event such as a description of the victim, the victim's last known location, and the status of any responding units. Once entered, this information is automatically symbolized in the view.
The staff member will continue updating the operation log throughout the incident as new information becomes available. The log file can be viewed but not modified. Originally just a text file, the log file was converted to an INFO database so that it could be categorized and searched and it has playback capability. The log file is both a useful diagnostic tool for debriefing and a legal safeguard should rescuers be called to testify in court.
If, in their haste to respond to the incident, rescuers cannot take time to supply GPS-generated coordinates, station staff supply approximate coordinates from a known places database or by querying the view. Coordinate information can be manually entered or can be imported as way points that have been captured by a GPS unit.
Calculations made by RescueView take the effects of variance and deviation into consideration. Variance is the magnetic displacement from true North localized for the immediate area. Deviation is the effect on the compass needle of components in the boat such as magnets or metal objects.
The Drift Locator, the most important enhancement to come out of the Table Bay experience, calculates the current position of the victim based on the last known position and drift information gathered by rescuers. Drift is determined by putting a swimmer into the water and noting the start and end coordinates and time. The Drift Locator extrapolates the victim's position. Course to Steer functionality uses information from the Drift Locator to plot a course that helps rescuers travel directly to the casualty.
Search Pattern functionality supplies coordinates for standard search patterns so that rescuers can systematically work a sector and know which areas have been covered. The search routes for each boat can be displayed on-screen.
Standard 1:50,000-scale topographic maps of the area that were scanned and georeferenced are used as a backdrop. These maps were chosen because nautical charts are available only at a much less useful scale, 1:250,000, and do not supply the kind of detail needed by rescuers. Lacking a readily available street network, the topographic maps also supply street information. The scanned maps have been augmented with a known place names database that contains coordinates.
Before RescueView was developed, the staff back at the station control room never knew what was going on and could not coordinate resources. In a major event, control staff could not keep the media apprised of the situation. With RescueView, station staff not only are aware of the current status of any rescue, they can actively assist.
RescueView, currently developed as a project, will be distributed as an ArcView extension after it has been exhaustively tested and further refined. Esri donated 27 copies of ArcView so that RescueView can be installed at all NSRI stations in time for South Africa's 2002 summer season.
For more information, contact Kobus Meyer at kobus_meyer@esri.com.
