Check it out – the NRCS Geospatial Data Gateway

I don’t know where I’ve been that I hadn’t heard about this before. I was flipping through a a Geoworld magazine (the last surviving GIS trade mag as far as I know) when I noticed that the resource of the month was the NRCS Geospatial Data Gateway; implemented by my former employer, the good ol’ USDA. I decided to kick the tires on their service. Read on for my take –

The interface is fairly straightforward, though you need to have a Java-enabled browser to make it work, which might hinder those with a slower computer or a slow internet connection. Though I have to say, if you’re downloading geodata sets, you shouldn’t be doing it in slowsville anyway.

You can use an interactive map or just look to the left & use the quick county or quick state selector. The interactive map is nice, though I think most users work on a state or county level. For power users, I’m guessing nine times out of ten the map interface wouldn’t be missed. Once you’ve got the area defined, it’s time to choose your data. They’ve got quite a selection, Including some newer products that DASC doesn’t have yet, like the 2006 NAIP imagery (1 meter resolution this year! Yay!). Also included are datasets for USDA Common land unit (CLU), hydrologic units, map indices, a whole mess of imagery, soils, & climate/precipitation data.

To test the system, I chose one vector & one raster dataset each. Feeling a bit nostalgic, I opted for the CLU (I digitized a lot of those buggers) and because it’s new, the 2006 NAIP. While selecting your data, you can highlight a selection from the list to get a preview image as well that all-important metadata (disable your pop-ups to see it). I have to admit I was kind of lost here, because it’s not entirely intuitive that you can only select one dataset for preview at a time. Plus, there’s a difference between checking & highlighting the dataset as well. Anyone who ever tried to teach someone ArcView 3.x will know what I’m talking about.

After getting un-lost & realizing that all the click-thrus for each step were always in the lower left of the screen, data selection became easier. I checked my selections, chose my preferred projection & data format, selected my method of receipt (FTP if you want it free), and gave them a bit of my personal info. With the request made, I was told to wait for a response in the next 15 hours that would allow me access to the FTP site for download. Seven hours later, I had an email with direct links to the FTP site, complete with the necessary passwords. No extra software needed; the web browser is quite sufficient. NRCS keeps your data available for 5 days, which is ample time to download even larger files. My 950 MB aerial took about 2 hours to download on my cable connection.

After downloading completed, I opened the ZIP files and was pleasantly surprised to find that the vector data was refreshed last week and metadata was included. Shapefiles and Zipfiles overlayed without a hitch. Kudos to the NRCS for allowing the user to select coordinate system & projection. At this time, only State Plane, UTM & Geographic are available, but that’s what most people use anyway, so it’s adequate.

Put this site in your bookmarks. This is another great free data resource!

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