Subsurface drip irrigation success depends on surpassing the backpressure obstacle, a phenomenon which occurs when water application intensity exceeds infiltration rate of soil, reduces emitter flow rate. Thus, this study aimed to determine variation, in relation surface flow, four emitters buried at two depths loam soil (Yolo Loam soil), and generated by subsurface condition. The cavity radius...

Methods for determining the parameters necessary for modeling fluid flow and contaminant transport in the shallow subsurface are in great demand. Soil properties such as permeability, porosity, and water retention are typically estimated through the inversion of hydrological data (e.g., measurements of capillary pressure and water saturation). However, ill-posedness and non-uniqueness commonly ...

The SWIFT2D surface-water flow and transport code, which solves the St Venant equations in two dimensions, was coupled with the SEAWAT variable-density ground-water code to represent hydrologic processes in coastal wetlands and adjacent estuaries. A sequentially coupled time-lagged approach was implemented, based on a variable-density form of Darcy’s Law, to couple the surface and subsurface sy...

Installing subsurface tile drain systems in poorly drained claypan soils to improve corn ( L.) yields could potentially increase environmental phosphorus (P) loss through the tile drainage system. The objectives of the study were to quantify the average concentration and loss of ortho-P in tile drain water from a claypan soil and to determine whether managed subsurface drainage (MD) could reduc...

1 Heterogeneity and lack of sufficient site characterization render accurate and reliable predictions of subsurface flow and transport in the vadose zone notoriously elusive. It is now widely recognized that for quantitative descriptions of subsurface phenomena to be scientifically defensible, they have to be accompanied by some measure of predictive uncertainty. In other words, a major goal of...

Numerical simulations of groundwater flow and chemical transport through three-dimensional heterogeneous porous media are described. The authors employ two CRAY supercomputers for different parts of the decoupled calculation: the flow field is computed on the T3D massively parallel computer, and the contaminant migration is simulated on the C90 vector supercomputer. The authors compare simulati...