I am a farmer and very new to GIS.
I am trying to load shapefiles or KML files to an online site/service called FarmLogs.com. Once my "fields" are uploaded the site can tell me the amount of rainfall on the fields. It can also display soil type maps. And GPS data from farm equipment (planters, sprayers, harvesters) can be overlaid.
The first step was for me to get the "shapefiles" from my county FSA office. They were sent to me as .JSON files which were not recognizable by FarmLogs.com. I searched around and found some online GeoJSON editors that would display the files and let me save them as .kml files or shapefiles (zipped .dfb, .prj, .shp, .shx). That worked!!, but here's the problem.
Mostly, each of the JSON files represents one "tract" of land (a few contain multiple tracts). The tract is basically one large polygon representing the outline of that tract. However, one tract usually consists of several smaller polygons. Some of these "sub-polygons" represent crop acres and some represent non-crop acres like houses, patches of trees in the middle of the fields, creeks, fence rows around the perimeter, things like that. But it's important that the GIS file I import into the FarmLogs.com site/service only represent the "crop acres", otherwise it doesn't accurately calculate per-acre metrics.
As a side note… I'd like to create 2 different "total maps" of the farm for my reference outside of the FarmLogs site. Ideally I could have them all in one Google Earth file with the "crop acres" tagged one way, and the non-crop acres tagged another, so I could visually distinguish and/or toggle them on/off. One that represents all the total land owned/farmed and another representing just the tillable land / crop acres. But to upload the files to FarmLogs.com, I need to be able to isolate the sub-polygons that represent crop acres and export or save them as .kml or preferably "shape files".
I've uploaded the JSON files to several free online editors which do a great job of displaying the overall tract and all the sub-tracts. I just downloaded QGIS 2.14.2 and it can read the JSON files, but only displays the overall tract boundary. To be more specific: QGIS, when I drag and drop a JSON file, finds 2 different "vector layers" that I can add to the project. One is a OGRGeoJSON with 1 feature of geometry type "Polygon". The other is a OGRGeoJSON with X features of geometry type "GeometryCollection". (Where X = the number of sub-tracts in the larger tract).
What free tools are available that can read a .JSON geoJSON file that will then allow me to select each "sub-polygon" and save it as it's own file then export to other formats?
Or does QGIS have a feature I can't find?
Best Answer
Step 1: Make a Selection of the specific sub-polygon
Step 2: Save your selection as a separate feature, but make sure to choose GeoJSON as your file save type