crops every 3 yr) and even continuous (annual) cropping in some instances. For example, annualized grain yields Water is the principle limiting factor in dryland cropping systems. for WCF are 75 to 100% greater than WF (Peterson et Surface soil physical properties influence infiltration and cropping al., 2000). Cropping intensification has been possible systems under no-till management may affe...

Data obtained from modified cone penetrometer experiments were used to estimate the hysteretic soil hydraulic properties with a parameter estimation technique which combined a numerical solution of the Richards equation with Marquardt-Levenberg optimization. The modified cone penetrometer was designed to inject water into a soil through a cylindrical screen, measure the infiltration rate with t...

Analytical solutions of the flow equation for infiltration offer an interesting tool for the hydrodynamic characterization of non-saturated soils by optimization of the hydraulic conductivity, Kfs, and the capillary sorptivity, So. However, the experimental conditions have to satisfy the governing assumptions. For falling head infiltration tests the initial water height, Ho, is a third unknown ...

study of the spatial variability of infiltration characteristics is essential to estimating infiltration parameters on a local scale. the objectives of the present study were to scale the parameters of a philip two-term model for infiltration and survey the variability of infiltration characteristics geostatistically using wastewater in the bajgah catchment. infiltration was measured at 30 poin...

known (Tillotson and Nielsen, 1984): (1) the dimensional analysis technique, which is based on the existence of Results with an empirically based one-parameter model showed physical similarity in the system; and (2) the empirical that the pore-size distribution index ( ) described in the Brooks and Corey formulation of soil hydraulic properties can scale the soil–water method, called functional...

Inverse optimization of parameters offers an economical means to infer soil hydraulic properties from in situ measurements of infiltration. We evaluated optimization strategies to inversely estimate soil hydraulic parameters using field measured tension disc infiltrometer data. We estimated the parameters n, , and Ks of the van Genuchten-Mualem (VGM) model, and a piecewise representation of con...

This paper describes the scientific principles of Darcy’s law and hydraulic resistance as they relate to the in-ground dispersal of onsite wastewater effluent. A clear understanding of how water moves into the ground via dispersal trenches is needed to facilitate proper system design and effect some standardization of dispersal trench sizing and design. Hydraulic conductivity of the media, hydr...