Biology professor needs a 3D map of the US, where the z-values represent particular species richness as opposed to the actual elevation of the terrain. The professor (and her GRA) came during my office hours with a delimited text file containing sample lat/long points along with the associated richness values.
Here's a quick shot of the result:
How many hours I spent on this:
Too many. At least 10 hours over the last month.
How I justify spending so much time on this project:
This is my first interaction with this biology professor, and I really, really want the professor to leave with a favorable view of the library's GIS services. I also worked closely with the professor's GRA, and I try to always take advantage of those teachable moments.
How I finally accomplished this task:
My first thought was that this would be a super-easy project. Unfortunately, this was not the case. This is probably due to my lack of experience working with the 3D functions of ArcGIS 3D Analyst/ArcGlobe/ArcScene. After this project, this should no longer be the case.
Here are the steps (from my notes):
- First Using ArcMap
- Create point feature class from sample data provided by the professor.
- Obtain U.S. state boundary shapefile from NationalAtlas.gov.
- Dissolved the continental (48 states) U.S.
- Converted the dissolved feature class to raster.
- Interpolated the sample points using kriging with the following parameters: (100 km radius kriging limit / 1 km cell size). The 100 km radius limit was requested by the professor.
- Merged the kriging layer with the raster U.S. layer.
- Next Using ArcGlobe
- Add merged raster layer
- Redefine raster layer as elevation.
- Exaggerate ArcGlobe by 1000. This was essential as this equated 1 richness factor = 1 km of elevation.
- Add the states layer, with hollow polygon symbology, to drape on top.
Why, develop a workshop of course. Keep your eyes peeled for a good workshop on these techniques planned for Fall 2006 semester. If the professor allows me to use the data points, this might really make some inroads into closer connections with he Biology department.
What about Google Earth?:
I would have to create a Tin (which is no problem) and then convert the Tin to KML using Arc2Earth. If I can find a free morning this summer (after finals...), I will compare how the elevation renders compared to ArcGlobe.