GIS

I haven't really said much about my job in my blog so far. People often ask me what I do, and I always have a hard time explaining most of it unless they understand acronymns like GIS, DEM, LiDAR, GPS, ESRI etc. And then for the rest of what I do, it's really good to understand what benzene, gas stations and the EPA have in common along with a whole new set of acronymns (PCB, PAH, VOC, PCP, BETX, DEQ, RBC, PRG, MTCA, etc. etc. etc.)

So, here goes for part 1: GIS.

Most of what I do every day is GIS (Geographic Information Systems). What is GIS? "GIS is a collection of computer hardware, software, and geographic data for capturing, managing, analyzing, and displaying all forms of geographically referenced information." My job is to display, analyze and sometimes create spatial data - that is, pretty much anything you can think of that has a location in the world. For example, some of our data sets are roads, tax lots, aerial photography, sampling locations, wells, buildings, and rivers. I use specialized software to make maps showing combinations of data (the "display" part),. I analyze different relationships between the data layers (maybe you'd ask "which eagle's nests are within 300 feet of this building" or "which houses for sale that are south of Freemont St, north of Broadway, west of 39th and east of 15th are in the Grant High School district, are within 1 mile of a park, have at least 3 bedrooms and are cheaper than $250,000?" - if you're from Portland you know the answer is "none!"). And sometimes I make new data layers through the analysis of what we already have or by manually digitizing in information (perhaps I'd make a new data set with only the tax lots of the houses meeting the above criteria).

Here's a real-life example: I recently worked on a project where there was a lot of contaminated dirt at a particular site in Washington. A field guy went out and collected soil samples (little jars of dirt) from the surface of the site and sent them to a laboratory where they determined what concentrations of nasty substances were in the dirt. As he took his samples, he used a super-high-accuracty GPS unit to record exactly (within about 1 meter) where he took the sample (creating spatial information). He then sent the GPS file to me, and the laboratory sent me all the contamination information. I joined up the x,y information (where the sample was taken in space) with the contamination information and compared the soil concentrations to standards set by the state (WA Dept of Ecology). I made a map showing where the soil concentrations were still too high, and the field guy directed the contractors to dig out the contaminated areas(analyzing spatial information). This process iterated through lots of times - they dug out a big area and took more samples, I figured out what areas were still too contaminated, they dug out more areas, etc. etc. ect. In the end, the field guy took over 1,000 soil samples. I made lots and lots of maps of the area showing where we took the samples and what areas had been dug out (displaying spatial information).

It can get incredibly more complicated, but that's a pretty straightforward example, I think. It's actually quite fun - I get to use a lot of problem-solving skills in planning out the analysis processes to efficiently get a useful result . And it's quite amazing all the applications that GIS has - cities and counties use it to track their utilities, emergency agencies use it to respond to calls, mapping websites use it to get driving directions, I've used it to evaluate relative rockfall hazards in subdivisions built near steep cliffs, it can be used to track wildfires, and on and on. In fact, if you've ever zoomed around on Google Earth, you've used GIS yourself.