I posted a few months ago about a new R package I wrote with Filipe Matias-- it's available for download on GitHub. Last week we extended the GitHub tutorial to include interpolation methods and raster visualization/mapping example code. Spatially Challenged readers have asked me to write tutorials on these techniques before, but I had been… Continue reading Inverse Distance Weighting and Kriging in R
Tag: maps
EJSCREEN: a tool for visualizing Environmental Justice
This week I learned about a great tool from the US EPA called EJSCREEN, which allows users to visualize and download data related to environmental justice. The US has a long history of environmental racism, including building highways through predominantly black neighborhoods and using former factory sites for low-income housing. Pollution and increased noise exposure… Continue reading EJSCREEN: a tool for visualizing Environmental Justice
Paper Size in QGIS 3 Print Layouts
I make most of my maps for publications and presentations in QGIS using the Print Layout feature. This is a wonderfully detailed tutorial if you want to learn more about print layouts. Right now I'm using the print layout to make maps of pH, organic matter, and soil test potassium to include in an update… Continue reading Paper Size in QGIS 3 Print Layouts
Global Yield Gap Atlas
I've used the Global Yield Gap Atlas for a few projects over the last couple years, and it's a great resource. GYGA measures the yield gap (difference between potential yield and achieved yield) of many crops grown in many environments, and provides downloadable data for other researchers. One tool I use from GYGA is their… Continue reading Global Yield Gap Atlas
US Satellite Images and #NoPlant19
Those of you complaining about the weather may feel validated by this headline from CNN (article here). For the over 1 in 10 Americans work in agriculture and related industries (source), this has real consequences. The increased rain this spring delayed planting, and in some places planting was prevented altogether. The Washington Post has some… Continue reading US Satellite Images and #NoPlant19
Data Downloads: Soil Maps
Today I'm continuing a series on sources of spatial data (see past posts on aerial images and DEMs). Soil maps are useful for all sorts of applications, like deciding where to place a trial in a larger field so that all the treatments are on the same soil type or determining the drainage class of… Continue reading Data Downloads: Soil Maps
Inverse Distance Weighting in SAGA
I broke out SAGA again this week to do some soil interpolations. I don't usually use inverse distance weighting (IDW) for much because you can't generate error maps or use covariates with this method. For this project I needed to make some maps in IDW to compare back to other methods. I'm using IDW for… Continue reading Inverse Distance Weighting in SAGA
Saving Layer Style Files in QGIS
Sometimes getting a layer to be displayed precisely how you want it can be a tedious process in QGIS. Fortunately, there is a way to save that style so you can apply it to the same layer in another project, or to another layer with similar attributes. Most of the time I use layer style… Continue reading Saving Layer Style Files in QGIS
Getting Category Colors into QGIS from ColorBrewer
Are you as obsessed with ColorBrewer as I am? I am making a map where I color Ohio counties based on region, and used ColorBrewer to pick colors. The first thing I did was go to ColorBrewer and find a qualitative color set for 5 categories of data. Next I used the HEX codes provided… Continue reading Getting Category Colors into QGIS from ColorBrewer
EPSG Numbers and Coordinate Reference Systems
Over the last month or so I've had a little series about how we describe positions on the globe and how we visualize spherical space on a 2D map. I started with big picture information, like why we care about map projections. Last week began giving more concrete advice for picking a projected or unprojected… Continue reading EPSG Numbers and Coordinate Reference Systems
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