LINKFLOW, A WATER-FLOW COMPUTER-MODEL FOR WATER-TABLE MANAGEMENT - PART 3 - MODEL APPLICATION

A computer simulation model, LINKFLOW, was developed to compute the mo vement of water during various water table management practices. The d evelopment of the model and validation with field data has been covere d in related articles (Havard et al., 1995a,b). This article describes the use of the model to investigate the effects of anisotropy and cla y lenses on water table elevations during water table management. The first application considers subirrigation and drainage in an anisotrop ic soil, and the second describes effect of clay lenses on subirrigati on and drainage system performance. The results of simulations suggest that water table management system performance can be significantly a ffected by soil anisotropy. Case simulations for subirrigation and dra inage showed 18% and 25% reductions in water movement into and out of the drains respectively when the anisotropy of the soil increased from one to five. Further simulations showed the effect of clay lenses in the soil profile and how backfilling during installation would benefit subirrigation and drainage system performance. Backfilling around the drains for a soil with low permeability lenses showed 70% increase in water flow after 21 days of subirrigation.