TY - RPRT TI - SUTRA— A code for simulation of saturated-unsaturated, variable-density groundwater flow with solute or energy transport—Documentation of the version 4.0 enhancements—Freeze-thaw capability, saturation and relative-permeability relations, spatially varying properties, and enhanced budget and velocity outputs AU - Clifford I. Voss AU - Alden M. Provost AU - Jeffrey M. McKenzie AU - Barret L. Kurylyk PY - 2024 DO - 10.3133/tm6a63 UR - https://pubs.usgs.gov/publication/tm6A63 ID - tm6A63 ER -