Wednesday, September 30. 2009

Geography Explains Why AIDS Levels Low in West Africa, Epidemic in East

Researchers at the University of Florida led the team that solved the mystery. The situation is this: infection rates of those with the viruses that cause AIDS held steady at relatively low levels for more than 50 years in west central Africa but jumped up to an epidemic in east Africa in the 1970s.

The explanation:

Essentially, the explanation for the HIV explosion — obscured until now — involves the relative ease with which people can travel from city to city in east Africa as opposed to the difficulties faced by people living in the population centers of the Democratic Republic of Congo, the point where HIV emerged from west central Africa in its spread to the east.

- press release

GPS in the Snow

Recall that one of the errors in GPS is called "mulitipath error" - that's when the signal from the GPS satellite bounces off something before it gets to the receiver, making its path artificially "longer." Its noise for most applications, but in fact is valuable in ... wait for it... measuring snow depth. Researchers at the University of Colorado, Boulder, looking to learn about the impact of soil moisture on the echoes found their experiment in the middle of a snow storm. That lead to a startling realization: "The snow slowed the reflected GPS signals, and the delay corresponded to the snow's depth..." That in turn led to a method to accurately measure snow fall in real time. The team's paper, in Geophysical Research Letters appeared this month.

- ScienceNow

SpatialKey Following in FortiusOne's Footsteps

I found this blog post on SFWeekly which linked to post on the SpacialKey (sic) blog. The SpatialKey Blog post details how the company, on its own, read an article in the San Francisco Chronicle about Operation Safe Schools, downloaded data from SFData.gov did some analysis (video below) and came to some conclusions. The post does note the conclusions have a bit of an asterisk on them, since they deal with drug busts and schools, but the data used was collected in the summer when school is out. The post also makes clear that the company has no relation to the city, but would love to speak with them. Transparency = good! There's also a step by step discussion of how SpatialKey was used which can be used as a tutorial.

I note this blog post because it parallels what FortiusOne does with its Dataset of the Day posts (blog). These tend to deal a bit more with analysis even as they highlight freely available datasets. These efforts are great resources for GIS professionals and educators. Should your organization be offering this sort of materials?

Volunteers Use Google Maps to Track Philippine Flooding

The map, created and maintained by volunteers highlights the situation after Typhoon Ondoy (international name: Ketsana) dumped a month’s worth of rain in a day this past Saturday. I'm pleased to report that all the points I checked did have a filled in source field.

- Manilla Bulletin