Get and prepare basic soil hydraulic parameters from SSURGO via SDA

prepare_SSURGO_hydro_data(cokeys, max.depth)



vector of component keys (cokey) in current SSURGO snapshot


target depth of aggregation (cm), corrected later by real soil depth as reported by slab()


a list containing:

  • SPC: SoilProfileCollection

  • agg: aggregate representation of hydraulic parameters, by cokey

The following soil hydraulic properties are included:

cokeycomponent key
hznamehorizon name
hz_tophorizon top depth (cm)
hz_bottomhorizon bottom depth (cm)
thickhorizon thickness (cm)
satVWC at saturation (cm/cm)
fcVWC at field capacity or 1/3rd bar tension (cm/cm)
pwpVWC at permanent wilting point or 15 bar tension (cm/cm)
awctotal sand content (<2mm fraction, mass %)
sandtotal silt content (<2mm fraction, mass %)
silttotal clay content (<2mm fraction, mass %)
claytotal sand content (<2mm fraction, mass %)
dbthirdbarbulk density at 1/3 bar tension (g/cm^3)
ksatKsat (um/second)
soil_fractionvolume fraction of soil (1 - coarse fragment volume fraction)


Weighted mean soil hydraulic parameters are returned over the interval of 0-max.depth, calculated by aqp::slab().


D.E. Beaudette