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Showing posts from December, 2017

Elevation, latitude...

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Here's a question that seems perfect for GIS - in fact, it's probably trivial for a skilled GIS person. I have a farm in Hawaii, at approximately 20 degrees latitude, 750 meters elevation, and 3-4 meters of rainfall annually.  Let's say I'd like to visit farmers elsewhere in the world - say, India or Central America - which have similar conditions.  Where are they? I'd guess this would involve making three areas, those with similar elevation, similar latitude, and similar rainfall, then finding their intersection. The first decision, technically, would seem to be answering this question with rasters, or vectors.  Both are technically possible, and I know that the elevation data is going to start as rasters, but I believe that GIS software more commonly does "intersection" with polygons, so I'll try that. Part 1: Elevation I grabbed some common free data ( GMTED2010 ) from the USGS, loaded into QGIS, and used Layers: Properties: Band Rendering

New blog for experiments

I've been a "geo person" since the 90s, but almost always as a tool maker , not as a tool user .  Despite years of writing and supporting 2D and 3D geovisualization software, I've never really used  regular GIS software. Sure, every few years I've fired up ESRI or FOSS GIS tools for a quick spin, but never used them to do real work - and as for the hipster neo-geo world where everything seems to be GeoJSON in The Cloud, I've barely ventured.  Hence, a blog to share some of my learning adventures.