ABSTRACT-Determining hydraulic conductivity of soil is difficult, expensive, and time-consuming. In this study, Algorithm Genetic and geostatistical analysis and Neural Networks method are used to estimate soil saturated hydraulic conductivity using the properties of particle size distribution. The data were gathered from 134soil profiles from soil and lander form studies of the Ardabil Agricul...

Hydraulic conductance was measured on leaf and stem segments excised from sugarcane plants at different stages of development. Maximum transpiration rates and leaf water potential (V'L) associated with maximum transpiration were also measured in intact plants as a function of plant size. Leaf specific hydraulic conductivity (LsJ and transpiration on a unit leaf area basis (E) were maximal in pl...

A linear estimator, cokriging, was applied to estimate hydraulic conductivity, using pressure head, solute concentration, and solute arrival time measurements in a hypothetical, heterogeneous vadose zone under steady state infiltrations at different degrees of saturation. Covariances and cross-covariances required by the estimator were determined by a first-order approximation in which sensitiv...

Loss of hydraulic conductivity occurs in stems when the water in xylem conduits is subjected to sufficiently negative pressure. According to the air-seeding hypothesis, this loss of conductivity occurs when air bubbles are sucked into water-filled conduits through micropores adjacent to air spaces in the stem. Results in this study showed that loss of hydraulic conductivity occurred in stem seg...

Ischemia-reperfusion (IR) injury is a major insult to postcapillary venules. We hypothesized that IR increases postcapillary venular hydraulic conductivity and that IR-mediated changes in hydraulic conductivity result from temporally and mechanistically separate processes. A microcannulation technique was used to determine hydraulic conductivity (Lp) in rat mesenteric postcapillary venules seri...

Hydraulic conductivity of the xylem is computed as the quotient of mass fiow rate and pressure gradient. Measurements on excised plant stems can be difficult to interpret because of timedependent reductions in fiow rate, and because of variable degrees of embolism. Using Acer saccharum Marsh, stems, we found that certain perfusing solutions including dilute fixatives (e.g. 0.05% formaldehyde) a...

We investigated the role of increasingly well-constrained geologic structures in the subsurface (i.e., subsurface architecture) in predicting streambed flux and hyporheic residence time distribution (RTD) for a headwater stream. Five subsurface realizations with increasingly resolved lithological boundaries were simulated in which model geometries were based on increasing information about flow...

With the aim of setting up a simpli®ed method to measure hydraulic conductivity of structured soils at saturation, a method reported by Ahuja et al. (Soil Sci. Soc. Amer. J. 48 (1984) 699±702; Soil Sci. 148 (1989) 404±411), which also refers to the generalised equation of Kozeny±Carman and the scaling theory, is tested in this paper. Data were elaborated from hydraulic conductivity measurements...

Saturated hydraulic conductivity of Soil is an important property in processes involving water and solute flow in soils. Saturated hydraulic conductivity of soil is difficult to measure and can be highly variable, requiring a large number of replicate samples. In this study, 60 sets of soil samples were collected at Saqhez region of Kurdistan province-IRAN. The statistics such as Correlation Co...

The main goal of this work is to determine and to evaluate the saturated hydraulic conductivity for a silt loam soil in field and laboratory conditions. The experimental area was located in the Vallcebre research catchments, in headwaters of the Llobregat River (NE Spain). Hydraulic conductivity was measured in the field using the Guelph permeameter and field saturated hydraulic conductivity (K...