Rose plants (Rosa x hybrida L. CV. Kardinal, grafted on Natal Brier) were grown in UC mix and in coconut coir. Water release curves and hydraulic conductivity of the media were measured. Water tensions in the media were maintained within a predetermined narrow range by tension-actuated irrigation, using high-flow electronic tensiometers. Transpiration rate of plants sitting on load cells was me...

It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of heterogeneous porosity fields. In this study, we use porosity and...

In order to better manage and monitor fluid flow and migration of chemicals in gas and liquid phases, a fundamental understanding and knowledge of the saturation dependency of permeability, diffusion and electrical conductivity in a porous medium is required. The initial fundamental formulations and recent research for characterization of transport properties in porous media are discussed. To i...

Comparison of the root system growth and water transport of southern pine species after planting in different root-zone environments is needed to guide decisions regarding when, and what species to plant. Evaluation of how seed source affects root system responses to soil conditions will allow seed sources to be matched to planting conditions. The root growth and hydraulic conductivity of three...

regarding the role and importance of subsurface drainage in water table control, many studies have been made throughout the world to find out new techniques and more economical solutions, especially as related to different pipe envelope material and their installations. this research was conducted to investigate the use of rice husk, as drain envelope material, in drainage installations. in add...

Based on the field measurements of the physical properties of fractured rocks, the anisotropic properties of hydraulic conductivity (HC) of the fractured rock aquifer can be assessed and presented using a tensor approach called hydraulic conductivity tensor. Three types of HC values, namely point value, axial value and flow direction one, are derived for their possible applications. The HC valu...

The Wells G and H Superfund site, located in the Aberjona watershed in Woburn, Massachusetts, has been studied by a number of MIT research groups since 1987. Initial research conducted to characterize the hydraulic properties of the wetland deposits, did not indicate the classical trend linking changes in hydraulic conductivity to changes in total porosity. It was hypothesized, therefore, that ...

Relatively small changes in the shape of the soil water retention curve near saturation can signi®cantly a€ect the results of numerical simulations of variably saturated ̄ow, including the performance of the numerical scheme itself in terms of stability and rate of convergence. In this paper, we use a modi®ed form of the van Genuchten±Mualem (VGM) soil hydraulic functions to account for a very ...

In this study we determine constitutive relations (relations between saturation, hydraulic conductivity and pressure head) for unsaturated fractured rocks using a computational procedure that mimics the laboratory technique of measurement. Isotropic three-dimensional rock samples with random vertical and horizontal fractures are computationally constructed. Each fracture is conceptualized as a ...

Following planting, western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings experience water stress and declining xylem pressure potential (Psi(x)). Low Psi(x) can result in xylem cavitation and embolism formation, causing a decline in hydraulic conductance. This study focused on the relationship between Psi(x), xylem cavitation and transpiration (E) of newly planted seedlings. Leaf specifi...