I recently spoke with Jon Hempel, Co-Director-National Geospatial Development Center, Soil Business Area Analysis Chair at the Natural Resources Conservation Service (NRCS) about GlobalSoilMap.net. One of the more interesting points in our discussion is the work being done to create raster vs. vector soil data for the entire world. Here’s Hempel on the utility of this new raster dataset:
“I believe about 90% of the nation has detailed soil-mapping completed. There are a number of different websites you can go to see this. The most popular one is called the Web Soil Survey (http://websoilsurvey.nrcs.usda.gov) and this is where you can locate and zoom into areas around the country and get data and interpretations for the soil information of that particular area.
The existing information is built on what is called a vector-data model, and you’re probably familiar with that, so it’s points, lines, and polygons. It’s displayed as such, and the information attached to each of the polygons is an aggregated data set, so there’s one data set that represents the entire polygon. Now, we know that there’s more soil information than just that one data set in the polygon, but, in the vector model, that’s how the information is presented.
Global-soil map.net will be displayed as a 90-meter raster grid, with each grid cell having its own specific data. With each cell having its own specific data, the raster presentation allows for data to be displayed on a natural continuum, as small nuances in the landscape changes, the soil data adjusts to those variations. Vector data only changes at the edges of polygons, polygons can be many hectacres in size. The other big difference is that the global soil project will display soil properties – rather than a mapunit aggregated value, we have individual soil properties attached to each raster.”
Read the full interview here.
