A Compact Constant‐Head Permeameter for Measuring Saturated Hydraulic Conductivity of the Vadose Zone

Amoozegar, Aziz

doi:10.2136/sssaj1989.03615995005300050009x

Cited by 159 publications

(78 citation statements)

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“…Input parameters of the lithotechnical units of Ischia island (Tofani et al, 2008). test using an Amoozemeter (Amoozegar, 1989). The parameters used as inputs to the HIRESS model are reported in Table 3.…”

Section: Lucca Pistoia and Prato Province Areasmentioning

confidence: 99%

HIRESSS: a physically based slope stability simulator for HPC applications

Rossi

Catani

Leoni

et al. 2013

Nat. Hazards Earth Syst. Sci.

138

115

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Abstract. HIRESSS (HIgh REsolution Slope StabilitySimulator) is a physically based distributed slope stability simulator for analyzing shallow landslide triggering conditions in real time and on large areas using parallel computational techniques. The physical model proposed is composed of two parts: hydrological and geotechnical. The hydrological model receives the rainfall data as dynamical input and provides the pressure head as perturbation to the geotechnical stability model that computes the factor of safety (FS) in probabilistic terms. The hydrological model is based on an analytical solution of an approximated form of the Richards equation under the wet condition hypothesis and it is introduced as a modeled form of hydraulic diffusivity to improve the hydrological response. The geotechnical stability model is based on an infinite slope model that takes into account the unsaturated soil condition. During the slope stability analysis the proposed model takes into account the increase in strength and cohesion due to matric suction in unsaturated soil, where the pressure head is negative. Moreover, the soil mass variation on partially saturated soil caused by water infiltration is modeled.The model is then inserted into a Monte Carlo simulation, to manage the typical uncertainty in the values of the input geotechnical and hydrological parameters, which is a common weak point of deterministic models. The Monte Carlo simulation manages a probability distribution of input parameters providing results in terms of slope failure probability. The developed software uses the computational power offered by multicore and multiprocessor hardware, from modern workstations to supercomputing facilities (HPC), to achieve the simulation in reasonable runtimes, compatible with civil protection real time monitoring.A first test of HIRESSS in three different areas is presented to evaluate the reliability of the results and the runtime performance on large areas.

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Section: Lucca Pistoia and Prato Province Areasmentioning

confidence: 99%

HIRESSS: a physically based slope stability simulator for HPC applications

Rossi

Catani

Leoni

et al. 2013

Nat. Hazards Earth Syst. Sci.

138

115

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“…The resulting functions were constrained (by displacing the curves vertically) to match measured values (see Table 1) of porosity (n) and saturated hydraulic conductivity (k sat ). Porosity was obtained by laboratory analysis of single samples removed from each layer of sediment, whereas for the saturated hydraulic conductivity it was possible to perform in situ Amoozemeter tests [Amoozegar, 1989] only for the most superficial layers 4 and 5. For the remaining layers, saturated conductivity was initially assumed from values reported in the literature for similar material types.…”

Section: Groundwater Flow Modelmentioning

confidence: 99%

Numerical simulation of hydrodynamics and bank erosion in a river bend

Rinaldi

Mengoni²,

Luppi

et al. 2008

Water Resources Research

200

141

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[1] We present an integrated analysis of bank erosion in a high-curvature bend of the gravel bed Cecina River (central Italy). Our analysis combines a model of fluvial bank erosion with groundwater flow and bank stability analyses to account for the influence of hydraulic erosion on mass failure processes, the key novel aspect being that the fluvial erosion model is parameterized using outputs from detailed hydrodynamic simulations. The results identify two mechanisms that explain how most bank retreat usually occurs after, rather than during, flood peaks. First, in the high curvature bend investigated here the maximum flow velocity core migrates away from the outer bank as flow discharge increases, reducing sidewall boundary shear stress and fluvial erosion at peak flow stages. Second, bank failure episodes are triggered by combinations of pore water and hydrostatic confining pressures induced in the period between the drawdown and rising phases of multipeaked flow events.

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“…We measured the field-saturated hydraulic conductivity in situ in the mineral soil at the depths of 12.5, 20 cm and 50 cm with an Amoozemeter, which is a Compact Constant-Head Permeameter (Ksat Inc., Raleigh; Amoozegar, 1989a). The procedure involved augering a cylindrical hole with radius r to the desired depth, establishing a constant head H such that H/r ≥ 5 and monitoring the outflow from the device until a steady-state flow rate is attained; at which point Ks can be calculated via the Glover solution (Amoozegar, 1989b).…”

Section: Field Measurements and Sampling Strategymentioning

confidence: 99%

Spatial and temporal variability of soil saturated hydraulic conductivity in gradients of disturbance

Zimmermann

Elsenbeer

2008

Journal of Hydrology

125

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Elektronisch veröffentlicht auf dem Publikationsserver der Universität Potsdam: http://opus.kobv. de/ubp/volltexte/2008/1640/ urn:nbn:de:kobv:517-opus-16402 [http://nbn-resolving.de/urn:nbn:de:kobv:517-opus16402] SummaryAs land-cover conversion continues to expand into ever more remote areas in the humid tropics, montane rainforests are increasingly threatened. In addition to the loss of biodiversity, land-use change potentially deteriorates regional water cycles, which may have undesirable effects for local populations such as decreased water supply during dry seasons, enhanced flooding in the rainy season, or deterioration of drinking water quality.Montane rainforests in the south Ecuadorian Andes are not only subject to man-made disturbances but also to naturally occurring landslides. I was interested in the impact of this ecosystem dynamics on a key parameter of the hydrologic cycle, the soil saturated hydraulic conductivity (synonym: permeability; Ks from here on), because it is a sensitive indicator for soil disturbances. Depending on the rainfall regime, the potential disturbance-induced decrease of Ks may become relevant for regional watersheds.My general objective was to quantify the effects of the regional natural and human disturbances on the saturated hydraulic conductivity and to describe the resulting spatialtemporal patterns. The main hypotheses were: 1) disturbances cause an apparent displacement of the less permeable soil layer towards the surface, either due to a loss of the permeable surface soil after land-sliding, or as a consequence of the surface soil compaction under cattle pastures; 2) 'recovery' from disturbance, either because of landslide re-vegetation or because of secondary succession after pasture abandonment, involves an apparent displacement of the less permeable layer back towards the original depth an 3) disturbances cause a simplification of the Ks spatial structure, i.e. the spatially dependent random variation diminishes; the subsequent recovery entails the re-establishment of the original structure.In my first study, I developed a synthesis of recent geostatistical research regarding its applicability to soil hydraulic data, including exploratory data analysis and variogram estimation techniques; I subsequently evaluated the results in terms of spatial prediction uncertainty. Concerning the exploratory data analysis, my main results were: 1) Gaussian uniand bivariate distributions of the log-transformed data; 2) the existence of significant local trends; 3) no need for robust estimation; 4) no anisotropic variation. I found partly considerable differences in covariance parameters resulting from different variogram estimation techniques, which, in the framework of spatial prediction, were mainly reflected in the spatial connectivity of the Ks-field. Ignoring the trend component and an arbitrary use of robust estimators, however, would have the most severe consequences in this respect.Regarding variogram modeling, I encouraged restricted maximum likelihood estimation becau...

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A Compact Constant‐Head Permeameter for Measuring Saturated Hydraulic Conductivity of the Vadose Zone

Cited by 159 publications

References 0 publications

HIRESSS: a physically based slope stability simulator for HPC applications

HIRESSS: a physically based slope stability simulator for HPC applications

Numerical simulation of hydrodynamics and bank erosion in a river bend

Spatial and temporal variability of soil saturated hydraulic conductivity in gradients of disturbance

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