+
+
+
+I am generally trying to avoid including actual spatial data sets
+(e.g. sf or terra objects) in with the MDChelp package
+to minimize the package size. Still, if there is some spatial data that
+can be expressed in tabular form and you don’t need the explicit
+geometry information, I can try to add it in.
+The only spatial objects included in the package are an sf object
+call counties.mo which is a spatial layer of all
+Missouri counties, and state.mo which is a single
+polygon of the state border. They are projected in NAD83 UTM 15N. Two
+NLCD data sets are also included as tabular data. They are the % and
+total area (square km) of several cover classes in each county. Cover
+classes are modified from the original data. See the help sections for
+each data set to see what changes were made.
+Most other types of spatial data can either be obtained from outside
+sources. Two R pacakges that facilitate this are tigris
+and FedData. Tigris lets you download sf objects of
+files from the national TIGER data set, while FedData lets you download
+spatial data from a variety of sources (NHD, NLCD, NASS, SSUGO, etc.)
+Your best bet is to look at those reference manuals, but I give a few
+quick examples here.
+
+
Plotting the Missouri spatial boundaries
+
+
This can be done easily with ggplot
+
+
+#not run
+
+MDChelp::counties.mo->counties.mo
+MDChelp::state.mo->state.mo
+
+ggplot(counties.mo)+
+ geom_sf()
+
+ggplot(state.mo)+
+ geom_sf()
+
+
+
#not run
+tigris::counties(state='MO')->counties.mo # census blocks
+
+tigris::blocks(state=29))->blocks.mo
+
+
+# school district boundaries
+# see tigris documentation
+
+tigris::school_districts(state=29)->schools.mo
+
+
+
There are a number of spatial, landcover, and weather data sets you
+can pull from. Definitley read the reference manual for this package to
+get a comprehensive idea of what data are available.
+
+# need a boundary shape. If it's not a rectangle or a square, one will be created internal to the function before extracting the data. The bounding area will be extracted from the min/max X and Y coordinates of the polygon.
+data(state.mo,package='MDChelp')
+
+
+#get NASS Cropland data layer data
+FedData::get_cdl(template=state.mo,
+ label='MO',
+ year=2023)->cdl.mo
+# returns a SpatRaster, a terra raster object class
+#get NHD data
+FedData::get_nhd(template=state.mo,
+ label='MO', #for use if writing the data to file vs storing in memory.
+ nhdplus=TRUE)->nhd.mo
+
+#Returns a list with 5 sf objects: Points,lines, flowlines, areas (streams and lakes), and water bodies.
+
+# get HUC12 data (the only scale available in FedData)
+
+FedData::get_wbd(template=state.mo,label='MO')->huc.mo
+
+#returns a sf object
+