Fig. 5. Soil matric head changes at the 1.5-m depth in three Hanford Barrier (HB) and two Hanford Barrier erosion–dune sand deposition (HB–dune sand) lysimeters, which received enhanced precipitation since November 1990. The HB lysimeters had no plants; the HB–dune sand lysimeters had shallow-rooted plants, but deep-rooted plants invaded lysimeter D12 for a short period during 1999.