A modeling framework to quantify the effects of compaction on soil water retention and infiltration

The water retention curve (WRC) of arable soils from the southeastern United States at different levels compaction (no compaction, and 10 20% increases in soil bulk density) was estimated using van Genuchten–Mualem (VG) model. VG parameters noncompacted were obtained first by fitting measured hydraulic data. To construct WRC compacted soils, gravimetric values permanent wilting point (?gw, 1,500 kPa) residual (?gr) content assumed to remain unchanged with compaction. parameter ? exponent ? after two approaches. In Approach 1, saturation, point, content. 2, value which allowed be immediately equation. 2 found give slightly better agreement data than 1. effect on saturated conductivity (Ks) predicted semitheoretical approaches VG-WRC function. HYDRUS-1D further used simulate vertical infiltration into a single-layered profile determine impact characteristics our analyses. Results showed that 10–20% increase density, due reduced cumulative (Ic) time T = Tfinal (steady-state) 55–82%, available storage capacity 3–49%, depending upon type.