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  • Complex confining layers. A stochastic analysis of hydraulic properties at various scales
  • This volume presents a study of the problem of characterizing the hydraulic properties, i.e. hydraulic conductivity and effective porosity, and ground water flow of complex confining layers at various scales. The study has shown that it is possible
  • to derive representative hydraulic properties at the scale of model blocks, from hydraulic properties measured at the score scale. - (AGD)
  • Hydraulic interpretation of sandsize distribution
  • Hydraulics and hydraulic geometry
  • A partial explanation of the dependency of hydraulic conductivity on positive pore water pressure in peat soils
  • Part of the relationship between positive pore water pressures and hydraulic conductivity in peat soils may be explained by accumulations of methane bubbles. The AA. show how compression and expansion of gas bubbles with changes in pore water
  • pressure could cause changes in hydraulic conductivity and thus help to explain some observations of dependency of hydraulic conductivity in peats on pore water pressure. Consideration is also given to the effect on hydraulic conductivities of methane gas
  • Hydraulics of interrill overland flow on rough, bare soil surfaces
  • A set of laboratory experiments on bare, rough soil surfaces was carried out to study the relationship between soil surface roughness and its hydraulic resistance. A new model is developed to predict the hydraulic resistance of the surface, based
  • on detailed surface roughness data. Roughness profiles perpendicular to the flow are used to calculate the wet cross-sectional area and hydraulic radius given a certain water level. The algorithm of Savat is then applied to calculate the hydraulic resistance
  • Hydraulics of sediment-laden sheetflow and the influence of simulated rainfall
  • This paper evaluates and compares hydraulic characteristics in flows with and without rainfall disturbance. The spatial uniformity of simulated rainfall properties, and its significance to flow hydraulics, are also discussed.
  • Sustained storage and transport of hydraulic gold mining sediment in the Bear River, California
  • This study examines the large deposits of hydraulic gold mining sediment and reevaluates Gilbert's (1917) classic model of sediment transport in a symmetrical wave that is based on hydraulic mining sediment primarily in the Yuba Basin. Sustained
  • storage and transport of hydraulic mining sediment in the Bear Basin are documented and a revised model of sediment transport is proposed.
  • Flow-separation berms downstream of a hydraulic jump in a bedrock channel
  • The purpose of this paper is to report the first direct observation of the phenomenon of gravel berm formation, downstream of a hydraulic jump. As the observations were fortuitous, detailed measurements of hydraulic conditions were not possible
  • but estimates were obtained. These observations are compared with laboratory experiments and theory. The deposits have significance in constraining flood palaeoflow reconstructions as the presence of berms determines the former location of hydraulic jumps.
  • Estimating unsaturated hydraulic conductivity from easily measured soil properties
  • The authors measured hydraulic conductivity (saturated and unsaturated) on 127 soil cores, which were taken in different horizons of a wide variety of Belgian soil series. The hot air method and the crust method were combined to obtain the complete
  • range of hydraulic conductivity from saturation to air-dry. Regression equations for estimating the Gardner parameters were established from simple soil properties, such as soil texture, carbon content, bulk density. Three parameters can reasonably well
  • be estimated from the textural composition and the saturated hydraulic conductivity.
  • Salt effect on hydraulic conductivity of a vertisol
  • The changes in saturated hydraulic conductivity, macroscopic swelling and clay dispersivity of a sodic black clay soil in relation to solution concentration and Na adsorption ratio of the percolating solution were measured. Based on the threshold
  • concentration curves, an empirical relationship relating saturated hydraulic conductivity and soil solution properties has been derived for vertisols and its field applicability established. For all practical purposes, swelling of clay seemed to be the major
  • factor responsible for loss of saturated hydraulic conductivity of a sodic vertisol.
  • Logratio linear modelling of hydraulic geometry using indices of flow resistance as covariates
  • This study develops a statistical model for the relationship between channel friction and at-a-station hydraulic geometry, which presents potential difficulties with regard to both non-linearity and spurious correlation.
  • Discriminant function analysis of compositional data: an example from hydraulic geometry
  • Compositional discriminant function analysis of bank stability on the basis of hydraulic geometry had a success rate of 88%, making routinely archived measurements of stream width, cross-sectional area, mean velocity, and discharge a readily
  • Ungauged catchment modelling II. Utilization of hydraulic models for validation
  • This paper presents the second part of an exploration of the application of developments made in hydraulic floodplain modelling to ungauged flood forecasting. A two dimensional finite element model, RMA-2, is applied to a 25 km floodplain reach
  • Hydraulic conditions for rill incision under simulated rainfall : a laboratory experiment
  • A series of controlled laboratory experiments were conducted in order to obtain precise data on the hydraulic and sediment transport conditions during rill formation.
  • English to metric conversion of hydraulic geometry and its significance to basins software
  • The purpose of this technical note is threefold : 1) to provide a derivation for the conversion formula and to prove that the slopes (i.e., hydraulic exponents) are, in fact, independent of units; 2) to correct an erratum that appeared
  • in the conversion formula and a related error in the BASINS User's Manual, Version 2.0 (USEPA, 1998); and 3) to discuss the significance of different systems of units for describing hydraulic geometry.
  • Landscape position, surface hydraulic gradients and erosion processes
  • Different hydraulic gradients, especially due to seepage or drainage, at different locations on a hillslope profile may have a profound effect on the dominant erosion processes. A laboratory study was designed to simulate hillslope processes
  • and quantity effects of surface hydraulic gradients on erosion for a Glynwood clay loam soil. Results showed that, under drainage conditions, interrill processes dominated and rilling was limited.
  • Establishing the role of pedogenesis in changing soil hydraulic properties
  • Chronosequences provide suitable sources for the study of changes in soil hydraulic behaviour as a result of long-term pedogenesis. For a podsol chronosequence in the Scottish Highlands, data are presented to indicate the changes that have occurred
  • over 13 000 years in the saturated hydraulic conductivity in each horizon. As the soil profile has evolved into a differentiated sequence of three horizons, the resulting hydrological changes can be both measured and quantified. The results
  • Experimental field assessment of suspended sediment pathways for characterizing hydraulic habitat
  • This paper describes a field methodology for exploring the transfer of particulate matter at small scales within river channels, which may be used to aid hydraulic habitat characterization. The field protocol combines field measurement of high
  • frequency flow properties, to characterize hydraulic habitat units, and deployment of spatial arrays of turbidity probes, to detect the passage of artificially-induced sediment plumes through different biotope units. Relationships between the nature
  • of spatio-temporal hydraulic variations within glide, riffle and pool biotopes, and the character and mixing behaviour of sediment plumes within these habitat units are identified.
  • Hydraulic erosion of cohesive riverbanks
  • This study identifies and assesses the controls on hydraulic erosion of cohesive riverbanks on a 600-m reach of an urban ephemeral stream with active bank erosion. The AA. examined hydraulic bank erosion by separating estimated bank shear stress
  • into 4 properties : magnitude, duration, event peak, and variability. The results suggest that the amount of hydraulic erosion of cohesive riverbanks is dictated by flow peak intensities. Finally, a conceptual model is produced for estimating bank erosion
  • Mechanical and hydraulic resistance relations in crust-topped soils
  • soil from the central Nile Delta, and a clay soil from the western region of the Nile Delta. Pertinent physical and chemical soil properties of the two soils were determined. Discussion of the results (mechanical resistance, hydraulic resistance, change