This study investigated the combined effect of temperature and single-species salt solutions on geotechnical properties (swell index and liquid limit) and hydraulic conductivity of bentonite applying different cation types, concentrations, and temperatures. Results showed that both the swell index and the liquid limit decreased with an increase in salt concentration irrespective of the type of ...

In this study, natural bentonite was used as natural clay material and samples were taken from the Kalecik district in Ankara. In this research, bentonite is the subject of an analysis from standpoint of assessing the basic properties of engineered barriers with respect to the buffer material. Bentonite and sand mixtures were prepared for tests. Some of clay minerals give relatively higher hydr...

Transmissivity results from eight aquifer tests were used to derive horizontal hydraulic conductivity values for hydrogeologic units underlying the Sequim-Dungeness Peninsula in Clallam County. Specific-capacity information for the tested production wells also was analyzed to obtain a second hydraulic conductivity value for comparison against the "aquifer test" results. These paired estimates d...

Hayashi, M. and Quinton, W. L. 2004. A constant-head well permeameter method for measuring field-saturated hydraulic conductivity above an impermeable layer. Can. J. Soil Sci. 84: 255–264. Hydrologic understanding of mountainous and northern regions of Canada is poor owing to the lack of critical field data such as hydraulic conductivity. A portable field instrument, the Guelph permeameter (GP)...

We present a new two-parameter expression for relative hydraulic conductivity (RHC) of partially saturated soils. It is based on the premise of Assouline et al. [1998] that soil structures evolve from a uniform random fragmentation process. This assumption allows us to derive hydraulic properties of soils (water retention curves and unsaturated hydraulic conductivity) from primary properties, s...

Hydraulic conductivity variations around the boreholes in uniformly graded sands for cyclic water injection pressure have been evaluated by laboratory tests. Prototype laboratory devices have been designed and constructed for this research. The cell has a capability to model the well, the boundary condition and to measure the hydraulic conductivity. While increasing water injection pressure, hy...

Variation in xylem structure and function has been extensively studied across different species with a wide taxonomic, geographical, and ecological coverage. In contrast, our understanding of how xylem of a single species can adjust to different growing condition remains limited. Here phenotypic and developmental plasticity in xylem traits of hybrid poplar (Populus trichocarpa×deltoides) was st...

is often still limited by the ill-posedness of the problem being considered. Ill-posedness in general is affected Inverse methods are increasingly used to estimate the hydraulic by nonoptimal experimental design, poor measurement properties of unsaturated soils. The method generally uses a weighted least-squares approach in which numerically simulated data are fitted quality, errors in the assu...

Hydraulic architecture parameters, water relation parameters and wood anatomy were studied in roots and shoots of the flood-tolerant tree Annona glabra L. on Barro Colorado Island, Panama. Hydraulic conductivity, leaf specific conductivity, and Huber value were similar to the corresponding values for tree species living in non-flooded habitats. The vulnerability of stems to loss of hydraulic co...

There are applications of barrier technology where the variability in hydraulic conductivity from point to point in the barrier, in addition to the average hydraulic conductivity of the barrier, is important. Throughout this chapter, the following application will be referred to in order to demonstrate this point: use of a circumferential soil-bentonite cutoff wall to completely enclose a conta...