Solute Transport in Simulated Conductivity Fields under Different Irrigations

The interactive effect of irrigation methods and spatial variability of saturated hydraulic conductivity (Ks) on solute transport was determined with the combined use of a two-dimensional deterministic solute transport model and a stochastic parameter generator. In a homogeneous Ks field, the time required to infiltrate a prescribed amount of water or chemical increased from sprinkler to furrow to drip irrigation. Furrow irrigation appeared to leach the chemical more rapidly than either drip or sprinkler irrigation. Assuming the spatial distribution of Ks to be a stationary stochastic process, increased spatial variability in Ks reduced the infiltration rate. When Ks is spatially correlated, sprinkler irrigation appeared to be less susceptible to cause ground-water contamination than furrow or drip irrigation. The concentration distributions in the uncorrelated Ks field were not very different from those in the homogeneous field.