The groundwater flow is simulated with the seepage model of heterogeneity isotrope, and the partial differential equations are solved with finite difference scheme of irregular triangle net.
In the meantime the time variation of the water level in the ditch has been taken into account, therefore the groundwater head are time-varying as the groundwater flows toward the drain system.
While groundwater flows through an unconfined aquifer due to heterogeneity, the vertical average saturated hydraulic conductivity is a function of hydraulic head.
