Steady, Darcian, 1-D, 1-phase evaporation through a vertically inhomogeneous soil from a horizontal water table is simulated as an optimal control problem, i.e. the hydraulic properties of the porous medium (relative permeability of moisture and capillary water retention curve) are considered as control functions. The Richards nonlinear ordinary differential equation is integrated twice as a bo...

Estimation of field crop evapotranspiration (ETc) and its partitioning into evaporation and transpiration, are of great importance in hydrological modeling and agricultural water management. In this study, we used a dual crop coefficient model SIMDualKc to estimate the actual crop evapotranspiration (ETc act) and the basal crop coefficients over a cotton field in Northwestern China. A two-year ...

The need for improved crop water use efficiency calls for flexible modeling platforms to implement new ideas in plant root uptake and its regulation mechanisms. This paper documents the details of modifying a soil infiltration and redistribution model to include (a) dynamic root growth, (b) non-uniform root distribution and water uptake, (c) the effect of water stress on plant water uptake, and...

(1) Airflow is induced in the subsurface by applying a pressure gradient through vertical or horizontal wells or horizontal trenches. In SVE, this is usually accomplished by withdrawal, rather than injection, of air. The SVE gas flow increases rates of contaminant mass transfer to air in the unsaturated zone by evaporation of NAPL, volatilization of contaminants dissolved in pore water, and des...

Parlange, M.B. and Katul, G.G., 1992. Estimation of the diurnal variation of potential evaporation from a wet bare soil surface. J. Hydrol., 132: 71-89. Potential evaporation from a wet bare soil field was measured with a large sensitive weighing lysimeter on a 20 min time step for 5 days at Davis, California. The diurnal evaporation rate modeled with the Penman-Brutsaert model for potential ev...

Although short-rotation woody crop biomass production technology has demonstrated a promising potential to supply feedstocks for bioenergy production, the water and nutrient processes in the woody crop planation ecosystem are poorly understood. In this study, a computer model was developed to estimate the dynamics of water and nitrogen (N) species (e.g., NH-N, NO-N, particulate organic N, and s...

seed germination, is a new alternative to no-till in areas where poorly drained soils are dominant. Where soil moisture conditions are suitable, strip-tillage creates narrow-width tilled strips, traditionally in the fall, to increase early spring soil evaporation and soil temperature in the top 2 inches. This is particularly effective in poorly drained wet soils, where slightly raised soil stri...

this study evaluated the irrigation water management and different amounts of boron fertilizer affacts on yield and and water use efficiency of sugar beet. the two-factor factorial design in randomized complete block with three replications of irrigation and different levels of boron fertilizer for three years (2000-02) was designed in qazvin. the main four irrigation treatments were t1, t2, t3...

Soil moisture has been shown in many studies to be an important variable in numerical weather prediction (NWP) systems [1, 2, 3]. In many regions of the world, soil moisture exerts an important control on land surface evaporation, and is thus a determining factor in the partitioning of downwelling radiative energy incident at the surface. This energy partitioning into sensible and latent heat s...