A picture is worth a thousand words" especially in disaster relief.
Looking at a series of satellite images of Haiti taken before and after the January earthquake, it's easy to visualize how quickly the displaced population fled to open areas and created spontaneous settlements. In just three days, most of the green space in one Port-au-Princegolf course was replaced by tarps, tents and other temporary shelters housing thousands of people.Additional aerial views of Haiti show nearby water pipes, drains and dams still standing after the earthquake as well as blocked and passable roads. Public health officials have been using maps such as these to provide food, water and medical supplies to the displaced population and to prevent the spread of infectious diseases.
To do so, relief organizations including the U.S. Centers for Disease Control are tapping free, Web-based tools to create and share maps that have been instrumental in the medical community's response to the devastating earthquake. Never before have so many groups"from federal agencies to charitable organizations"been able to gather and distribute so much visual information about a disaster so fast.
"All of these tools allow people the capability to share and distribute information a lot quicker," said Jim Tyson, the situational awareness section lead with the CDC's Division of Emergency Operations. "In previous times, people and organizations would have had separate applications and separate databases built specifically for their needs. The technology architecture didn't allow for interoperability."
CDC's maps were created following a 7.0 magnitude earthquake that struck Haiti on Jan. 12. The epicenter of the quake was 10 miles west of Port-au-Prince, the impoverished capital of Haiti.The Haitiquake caused massive damage, with more than 230,000 deaths and 300,000 injured, according to the latest official figures. Nearly 2 million people lost their homes and were forced into temporary settlements with questionable water supplies and poor sanitary conditions.Immediately following the quake, first responders used free, open-source mapping tools like Google Earth to track the migration of the displaced population and the condition of roads. Because Haiti's Ministry of Health building collapsed, these tools also were used to survey the nation's health infrastructure, including the location of hospitals and health centers.Now that the immediate crisis is over, the medical community in Haiti is using these mapping tools to set up a health reporting and communication network to help prevent the spread of diseases ranging from diarrhea to cholera. The medical community is particularly worried about keeping the displaced population healthy during the rainy season, which lasts from May to July, and the hurricane season in August and September.In its response to the Haiti earthquake, relief organizations are pioneering new uses of multi-layered, standards- based maps along with other Web 2.0 communications channels to ensure the accuracy of these maps."By leveraging the technologies that are out there in the Haiti response, we have shown a magnitude of difference in how fast people were able to collaborate and discover who was working on certain elements of information," Tyson said.
Satellite tracks trends
The CDC is using Google Earth to manipulate satellite imagery of the Port-au- Prince area and to layer it with data elements that are useful to the public health community. Use of this open-source software application has allowed the CDC to develop maps using standard formats"including KML and KMZ files"that are easily shared and accessed by relief organizations in the region.
"The hardest part of this job is determining what verified and relevant data is out there that we can use,'' Tyson said. "It's specific data that needs to be overlaid and put in context with the situation. A lot of enabling technologies have been developed that allow us to take the time and the effort out of that process, which is very important from a public health perspective. We need to get the information, collaborate and share the information."
Within hours of the earthquake, the CDC had created a KML layer on a Google Earth map that showed every open area in Port-au-Prince where temporary settlements might occur. CDC sent out the map to the Department of Health & Human Services, the U.S.military and the Pan American Health Organization (PAHO), among others.
"First responders were able to determine rapidly where to put water stations and food stations because they knew days ahead of time where the thousands of people were settling," Tyson said, adding that these maps aided in search and rescue immediately and then in the ongoing reconstruction.
Next, CDC's situational awareness team created a map overlay with every known body of water, including rivers, streams and swimming pools. "We knew that it would only be eight hours before people were going to get thirsty, and within a day they'd be dipping into any standing body of water," he said.
Once CDC and other relief organizations created multi-layered maps of Haiti, Web sites such as ReliefWeb, Geo- Commons and Haiti Earthquake Data Portal popped up to share the data contained in the maps.
"It started with Google groups like Shelter Cluster Haiti that blossomed,'' said Dr. Jacqueline Burkholder, a public health scientist with CDC's Division of Emergency Operations. "There was a big effort to try to locate the health facilities in Haiti. We tried to agree on a way to identify each one and how to geo-reference it and agree upon how to determine the ability for those facilities to see patients."
CDC debuts Google Earth
The Haiti earthquake response is the first time that the CDC has used Google Earth and KML files.
"We've used paper maps and PowerPoint slides and some portal stuff, but this was the first time we were using other KML files and developing them ourselves," Tyson said. He added that the good thing about KML files is that they are small, easy to e-mail and can be applied to existing Google Earth data.
"You can send it to a BlackBerry, and the user can download it and click on the geo-references automatically on Google Earth," Tyson said. "When you pass your cursor over any spot, it will give you the latitude and the longitude. Our logistics folks had handheld GPS devices and could see any of the layers.''
Another open-source tool that CDC is using is Adobe Flex, a free framework for creating animated Web applications that can be viewed consistently by various browsers and operating systems using the Adobe Flash Player. The CDC used Adobe Flex to create a histogram of the rates of infectious diseases at settlement camps. The bars on the map go up and down, showing the disease rate over time.
The CDC is using this technique to map rates of infection from malaria, Dengue fever and other diseases.
"Using SWF Macromedia Flash Files, you can attach this data, and all you need is a browser to be able to see the numbers associated with the bars," Tyson said. "With some of the epidemiological data, this is the first time we are using SWF Macromedia Files. They are easy to attach to an e-mail, and you can use a Microsoft player to show the animation."
One benefit of using open, standardsbased mapping tools is that it will be easier for the CDC to hand off the data it has collected to the Haitian government when the earthquake relief effort ends.
"We have 50 sites where CDC is actively collecting data. The goal for those sites is to turn the data over to the Haiti Ministry of Health,'' Burkholder said. "The way we are collecting it"in SQL databases, KML or XL data sheets"will allow the Haiti Ministry of Health to continue the surveillance."
Putting GPS
