Archive for the ‘geographic information systems’ Category

GIS and natural disasters

Thursday, November 17th, 2005

Thanks to Enrico from the intro GIS course for this post.

Here’s an interesting use of GIS for history/background information about natural disasters on National Geographic’s website.

It is a spatial application made using Macromedia Flash, so it has vector qualities and doesn’t take as long as ArcGIS to restructure all of the entities when changing the map extent. Once the Flash is loaded, everything is pretty much ready to go. The “Navigator” on the bottom right functions as the inset map that indicates where you’re zoomed in on and also as a means of moving the map extent within North America.

One also can view ALL dates of selected disasters or choose any increment of 25 years by ticking a box and sliding a rule along the bottom timeline.

When rolling over a natural disaster (a point), a small window pops up nearby to give quick facts. For tornatoes and hurricanes, their paths (represented by polygons and a lines, respectively) are highlighted when the mouse is over their point. Larger disasters allow you to click on them to bring up detailed information. These attributes are videos, photos with captions, and large text blocks of information.

There is a nice color scheme that makes it easy to distinguish between types of “forces of nature,” and the scheme is continued when following the links of the larger disasters. Each type of disaster also has a different shape for its “point” representation on the map, making it even easier to distinguish among them.

This application is useful in understanding the spatial trends of hurricane and tornado origins and paths as well as seeing evidence of volcanoes and earthquakes along the “ring of fire.” This example of GIS can be used for public general interest or as a fun way to educate students about the forces of nature.

GIS for effect, disease, and outbreak response

Tuesday, November 15th, 2005

Thanks to Andrea for this post.

Public health needs are most often at the forefront of international discussion. Disease outbreaks need to be readily dealt with, as to minimize effects. The tragedy of epidemics is to great to risk. Proper planning, with up-to-date and useful information, is needed in any effective decision-making process. GIS has become an invaluable tool to address public health needs.

With the development of the Public Health Mapping and GIS program in 1993, the World Health Organization can now map disease outbreaks, assess epidemic risk and analyze epidemiological data. Analysis of spatial data in tabular format often misses details and trends in space. GIS has facilitated decision-making processes by creating a visual representation of disease to look at outbreak control, monitoring and management.

The roles of GIS in WHO’s Public Health Mapping and GIS program include: determining the geographic distribution of disease, analyzing spatial and temporal trends in disease, determining populations at risk and other risk factors, and planning resources, targets, intervention and monitoring needed to mitigate impacts of the disease.

GIS maps diseases outbreaks in relation to social and ecological variables that may factor into the spread of the disease, such as population demographics, the natural environment and existing health services. Visualization of the problem aids in targeting areas of greatest concern, for more effective disease treatment and control.

Mapping of disease is not a new thing, but GIS can do this faster than ever before. The speed at with GIS can map the distribution of disease and the social and ecological that may play a role in the spread of the disease can get aid to the areas its most needed, fast. There is great hope in the fact that GIS can target areas that lack the health resources to deal with disease outbreak, making aid more readily available to those who do not have the basic, required health resources and to those in areas of high risk.

WHO’s HealthMapper describes applications of the Public Health Mapping and GIS program. Over 500 people in 70 countries have been trained to use GIS software; this has resulted in the mapping of HIV/AIDS risk worldwide, malaria spread in Ethiopia and post-tsunami relief in Indonesia. The visual representation of disease leads, not only to better and more prompt decision-making processes in disease control, but also to better public awareness and understanding of epidemics.

Check out WHO’s Global Atlas for interactive maps on disease distributions. The site also contains excellent encyclopedic descriptions of the use of GIS for health mapping.

Dental topography

Monday, November 14th, 2005

Thanks to huds for this post about Dental Topography and Food Deserts: The Role of geographic information systems (GIS) in our Diets

A more scrumptious application of GIS technology allows food scientists to not only “map out our appetites”, give the reasons for why we eat what we eat, but also gives us insight into what our ancestors ate!

At the University of Arkansas, a professor and his team of researchers managed to create GIS based methods to examine fossil teeth to help extract diet information. A combination of GIS software and laser technology gives insight into a dramatic shift in anatomical time, from more herbivorous habits to meat eating.

Why teeth?
“Teeth are perfect for testing diet hypotheses, because they are the best preserved items in the fossil record and are part of the digestive system,” said Peter Ungar, professor of anthropology. “But until now, we haven’t had the technology to pull much information out of them.”

That’s where GIS come in. Teeth shape can tell us what the initial chewing design was capable of, and the “wear and tear” gives clues into food habits and textures. With modern day benchmarks, the research team can get a pretty good idea of what we were all consuming back in the day.

Professor Ungar looked to technology to avoid time consuming manual analysis and gain better, more accurate results. “Dental landscapes” were examined by a high-resolution laser that reads three-dimensional coordinates of the teeth along the surface, which is coupled to GIS software that then calculates them and produces a 3-D map of one tooth.
The team’s analysis showed that Australopithecus afarensis had shallow slopes on their teeth, suggesting a diet of brittle foods like nuts, seeds, roots and tubers, while the teeth of early humans showed steeper slopes with greater shearing power, suggesting a dietary shift to tough meats.

Widely accepted archeological evidence argues the consumption of meat by early human ancestors, but it hasn’t been until Professor Ungar’s research that these dietary hypotheses can be supported!

To analyze more recent food habits, scientists at the UW College of Architecture and Urban Planning in collaboration with the UW School of Public Health have been able to map out the relationships between local environments and health to give insight into why certain population diets vary across regional settings.

Based on data collected via telephone surveys, the team links poor, unhealthy nutrition to socioeconomic status, spending power, and residential transportation accessibility, GIS based environmental variables were measured to highlight distances to fast food joints as opposed to health food stores, annual income and health food costs, and walking/exercise space in neighborhoods.

“The use of GIS offers many exciting ways to map the health-enhancing dimensions of neighborhoods”, the team insists.

I could eat to that!

See
Fat Neighborhoods: Spatial Epidemiolgy Meets Urban Form

Diet Information from Fossil Teeth

GIS and conservation biology

Sunday, November 13th, 2005

Thanks to “a tree lover” in the introductory GIS course for this post.

The Smithsonian National Zoological Park has an informative and interactive website concerning the use of GIS in conservation biology. Of particular interest, is a project called World forests: Biases in forest protection across world biomes. This project aims to assess the decline and protection of forests across the major biomes – temperate, boreal and tropical. The GIS application they created contained layers such as the estimate of the original coverage of forest, the current protected areas, and the modern forested area.

With this application they could then answers 3 questions :

  1. Did deforestation in past centuries differ among major global biomes-the boreal, temperate, and tropics? The GIS allowed them to determine that temperate forests declined the most (by 65%), followed by tropical forests (45%) and then by boreal forests (13%).
  2. How much forest remains in boreal, temperate and tropic zones? Of the total remaining forests in the world, 51% are in the tropical zones, 45% in the boreal zone and only 4% in the temperate zones.
  3. What is the degree of protection in these biomes relative to the degree of threat? Less than 5% of the remaining temperate forests are currently protected, for boreal forests the proportion is less than 4%, and for tropical forest more than 15%.

It is possible to see the resulting GIS application and even to use some of the tools of GIS (e.g., identify, query, and measure) with the conservation atlas of the Smithsonian Institute. We can see from these GIS results that more efforts must be directed towards protecting areas of the temperate forests.

These are your cells on a map, but how are your cells on a cell?

Monday, November 7th, 2005

Thanks to Leven for this.

In the US alone, it was estimated that there were 92 million cell phone users in 2000 and this number was growing by 1 million every month. The Cellular Telecommunications & Internet Association has estimated that there were almost 170 million U.S. cell phone subscribers in 2004.

Cell phones have steadily founded themselves in our everyday life, so much so, as to make them an attractive means for some scientific ends. In mid September, a geographical information system (GIS) application was built in the Austrian city of Graz, based on data from real-time cell-phone use. Tens of thousands of people carrying cell-phones were mapped using information from one of the leading local mobile companies. The ‘’Mobile Landscapes project’’ continually remaps the mobile positions according to the new information it receives. “For the first time ever we are able to visualize the full dynamics of a city in real time,” said project leader Carlo Ratti, an architect/engineer and head of the SENSEable City Laboratory at MIT. So you get to visualize these dynamics, by virtue of a neat representation of the density and ‘flows’ of users on the city map. Urban planning studies and applications will certainly find much usefulness in this. It could help transport engineers aiming at better freeway traffic management, may prove useful in large large-scale emergencies, as well in regulating emergency and safety precautionary measures, etc.

In another recent scientific endeavor, mobile phones were used in the field of medicine. A couple of weeks ago, it was reported that a Michigan hospital reduced by half the time it takes to begin life-saving treatment on heart attack patients, by using cell phones to transmit electrocardiograms (ECG) from the field. The patient calls his doctor not feeling well; the doctor begins to diagnose by running ECG’s with the help of the cell before the ambulance gets to unpark. The medical staff are better prepared by the time the patient arrives at the hospital. Sounds pretty good huh?

Not always. Over these past years, however, when health was the issue- cell-phone usage had been burning tissue rather than preventing (or better preparing for) heart-attacks. Some research suggests that radio-frequency cell-phone emitted radiation not only heats cell tissue but breaks it up and mutates cell DNA. The most recent such study of significant size is the REFLEX Project (which stands for Risk Evaluation of Potential Environmental Hazards from Low Frequency Electromagnetic Field Exposure Using Sensitive in vitro Methods).

A four-year study that surfaced almost a year ago was conducted by 12 research groups in seven European nations and was two-thirds funded by the European Union. The REFLEX Project studied electromagnetic fields (EMFs) in the extremely low frequency (ELF) region, coming from the ordinary electricity supply and appliances, and in the radio frequency (RF) range emitted by mobile phones. The study was looking for the effects on human and animal molecules after exposures to EMF for short periods of time: from 6 hours to 24 hours and at most up to a few days. The effects of long-term exposures were not addressed.

Despite this, what many groups found was that exposure to electromagnetic radiation caused significant DNA breaks in human and animal cells. DNA damage occurred even when radiation levels were often far below the official limits. This damage could not always be repaired by the cell and it would persist in the next generation of cells. Despite these findings, the concluding report stated the following:

Taken together, the results of the REFLEX project were exclusively obtained in in vitro studies and are, therefore, not suitable for the conclusion that RF-EMF exposure below the presently valid safety limits causes a risk to the health of people.

So damaged and mutated cells are not necessarily a bad thing! This is, of course, a very controversial and ‘sensitive’ topic, and this is aptly reflected in the conclusive remarks of many different studies. It is however, one that definitely deserves our close attention considering the heavy, and intimate (touches our head, maybe the waist too), use we make of this technology.

Anyone interested in more info on other ‘cell-phone effect’ studies,

Radio frequency safe devices

Court case in Maryland and many other links

Israel TECHNION on sight

Institute of Science in Society

Google Maps go Mobile

Monday, November 7th, 2005

Tomorrow, Google is set to expand mobile phone mapping service. As long as your phone has a GPS, Google Maps will plot your location automatically on your cell phone. Oh, and as long as your cell phone uses one of the supported services, that is your phone service is from Cingular, T-Mobile and Sprint. Forget it, if you have Verizon phones, Blackberries or Palm OS PDAs. No word on Rogers or Fido.

New satellite imaging reveals rainforest devastation

Saturday, October 22nd, 2005

New satellite imaging techniques have revealed that the Amazon rainforest is being destroyed twice as fast as previously thought.

Scientists have discovered that previous satellite photographs of the Amazon have missed a form of surreptitious logging that is equally destructive, but not as apparent from space.

Now a team of American and Brazilian specialists have for the first time been able to assess from space the damage done by “selective logging”, when one or two trees are removed leaving surrounding trees intact.

More on the imaging:

Scientists have been working for eight years to find a way of detecting the large-scale damage caused by selective logging. From this work emerged the Carnegie Landsat Analysis System (CLAS) which processes data from three Nasa satellites. The information is fed into a powerful supercomputer which can spot changing patterns within each image pixel.

“For example, the signals tell us how much green vegetation is in the canopy, how much dead material is on the forest floor and how much bare soil there is,” said Dr Asner [, head of the study]. “Extracting those data has been a Holy Grail of remote sensing. With CLAS, we’ve been able to obtain a spatial resolution of 98ft by 98ft for the Brazilian Amazon Basin. That’s huge.”

I don’t know whether to call this positive technological innovation or not, considering how depressing the findings are.

Click here and here for more info on the Stanford work.

Open source and innovation

Friday, October 21st, 2005

To what extent does our software have to be free or shareware to encourage innovation and research? This NYTimes article points to the new phenomenon called map mash-ups that has arisen because of Google’s free api.

What I find exciting is the “meta-multiplier” effects. It’s happened in the growth of third party value-add ons. In the US, the inexpensive and broad-based distribution of Census data made much of GIS software development (read-survivability) possible; without this easily accessible digital data, we wouldn’t have seen the advent of digital gazetteers. Basic map api’s such as Google maps build on this data availability and have created a platform for new companies such as Homepricerecords.com. These api’s also have created new opportunities for public participation GIS. Think of www.scipionus.com, an application to help people affected by Hurricane Katrina. This interface was built on top of Google maps in 1 1/2 hours.

Obviously Google has a very different business model from ESRI. However, even ESRI has made its modeling interface “open source”. What’s next? ArcIMS?

Useful, but is it legal?

Monday, October 3rd, 2005

William Bright, a a design director at Nerve.com, decided it would be a great idea if people could access subway maps on their iPods. So he chopped the maps into pod sized pieces and offered them for download. Thing is, these images are copyrighted and the copyright holders, the subway authorites, got mad and went after him. (Well, after his site got noticed by a blog, he got noticed by the authorities.)

The sad lesson is, someone may create something imminently useful, perfectly suited to a technological innovation, and free and it still may run afoul of the law.

See Washington Post and wired for further details.

Rita and new uses of the Internet

Wednesday, September 28th, 2005

As never before, Hurricane Rita prompted high use of the Internet to inform the general public. This article mentions several.

For example, the Houston Chronicle featured on-site blogging before and during the hurricane from about a dozen “citizen” bloggers. Additionally,

Web surfers were able to get firsthand accounts Friday through podcasts and photographs. They could track the storm using Google-powered maps. And they could find housing and other emergency information from government and private Web sites.

They established a live streaming feed called RitaCast and made arrangements to produce a new personal audio dispatch every hour, each about 20 minutes long. The group was even trying to take calls from listeners — something rare with podcasts.

One interesting item, implied in the article, was as some television stations were flooded out of their offices and newspapers couldn’t operate their paper plants, they turned to webcasting.

BTW, the Washington Post has an excellent interactive map of Rita’s impact (although it did crash Firefox). You also may want to check out FLHurricane.com, which can track the movement of hurricanes on a map. The site combines Google’s map api with data from the National Weather Service. The site’s administrator, Mike Cornelius, wrote software to automatically extract latitude and longitude coordinates from government storm advisories.

Satellites and New Orleans wetlands

Saturday, September 17th, 2005

Scientists, policy makers, and the public have made enormous use of satellite images since Hurricane Katrina struck (e.g., see here). Using these images, NASA has just reported how important wetlands are in absorbing flood waters.

GIS-assisted picture of fraud

Saturday, September 17th, 2005

I read about this investigative series, about to be published in the South Florida Sun Sentinel, about the massive corruption at the US Federal Emergency Management Agency and came across this paragraph on how they did the analysis:

Reporters overlaid maps of the various storms and disasters with maps of where FEMA money was spent. The newspaper tracked some one million claims, Mauker said.

Update: The first article in the Sun-Sentinel series has just been published.

GIS and Tennis

Sunday, September 11th, 2005

(From time to time I’ll post information that students send me on interesting applications of geographic information systems. This time from “Tennis Fan”:)

Looking for that competitive edge?

Professional Tennis and Cricket have a new tool in helping players form winning strategies. The ‘Hawk-Eye’ tracking device, used since 2001 in telecasting, processes data from multiple cameras on a Tennis court or Cricket pitch to form a 2D or 3D image pinpointing landing spots within 2 or 3mm on a respective court or pitch.

If you are a tennis fan, you will recognize this technology in the computer generated replays, used in broadcasts of major tournaments, often showed after a controversial call by the umpire or a particular close call at the baseline. In tennis, the use of many cameras on the court allow for three dimensional recreation of ball trajectory and precise landing point location. What’s the use of such technology? Asides from making broadcasters sound smarter by giving them loads of additional statistical data, the Hawk-Eye technology allows for better understanding of player’s strategy.

The following link is to an article at bbcnews.com detailing Venus Williams’ service pattern against Maria Sharapova in the Wimbledon 2005.

Using a vector spatial data model, the article examines the landing points of Williams’ first serves and Sharapova’s return hit points in the first and second set. In the model, first serve landing points and returns are shown as yellow circles and second serve returns as black circles. The white lines are the court delimitations, and a net is added to increase the realism of the CG representation. We can notice that the black circles in the return pattern are on average closer to the net, indicating slower second serve speeds. The article states that Williams’ strategy was to “serve the ball into Sharapova’s body – a sensible tactic against a tall player with a long reach.” This can be seen in the dispersal of the first serve points on the model. Had she wanted to make Sharapova move around more, hypothetically speaking, the model might have shown a higher concentration of landing spots in both corners of the service square. The article also mentions “there was no discernable change of tactic by Sharapova in the second set” meaning the the ball patterns of return hits were similar in both sets. Had Sharapova understood Williams’ strategy and decided to become more aggressive, she could have advanced into the court and thus the yellow circles on the model would have been closer in. The result: Venus beat Maria in two sets of 7-6 and 6-1.
So there you have it, if you have a big match against one of your buddies coming up and you really need that edge, hire Hawk-Eye Innovations to analyse his/her tactics. This will allow you to inflict severe ego-bruising pain on your unsuspecting fair-playing opponent… shame on you!

Click here for an additional article on Hawk-Eye.

Enjoy!