scholarly journals Characterization of the field saturated hydraulic conductivity on a hillslope: measurement techniques, data sensitivity analysis and spatial correlation modelling

2005 ◽  
Vol 2 (4) ◽  
pp. 1247-1298 ◽  
Author(s):  
C. Fallico ◽  
E. Migliari ◽  
S. Troisi
Keyword(s):  
Sensitivity Analysis ◽  
Hydraulic Conductivity ◽  
Spatial Correlation ◽  
Unsaturated Zone ◽  
Measurement Errors ◽  
Measurement Techniques ◽  
Saturated Hydraulic Conductivity ◽  
Spatial Correlation Structure ◽  
Disc Infiltrometer ◽  
Data Sensitivity

Abstract. In the context of studies aiming at the estimation of effective parameters for unsaturated zone modelling, this work tackles the problem of experimental data quality, considering the large collection of data gathered at an experimental site equipped for unsaturated zone hydraulic monitoring in the alluvial basin of a Calabrian river, in the South of Italy. Focusing attention on field saturated hydraulic conductivity, the in-site measurement techniques by tension disc and pressure ring infiltrometers are considered, pointing out the main indications for the correct use of each measuring approach; laboratory techniques are also considered. Statistical data analysis showed that the measurements performed by tension disc infiltrometer supplied values of hydraulic conductivity which are on average lower and more homogeneous than the values provided by the other measurement techniques considered. Sensitivity analysis was then carried out by Monte Carlo simulation on the parameter sampling achieved by field measurement techniques in order to evaluate the influence of any possible small measurement errors on the data. Sensitivity analysis showed that both ring and disc infiltrometer are tools reliable enough for the in situ measurements of field saturated hydraulic conductivity. Finally, after a data merging procedure giving origin to different sets of data, the spatial correlation structure of field saturated hydraulic conductivity is investigated, using well-known geostatistical techniques.

ESTIMATING VERTICAL SATURATED HYDRAULIC CONDUCTIVITY FROM SOIL MORPHOLOGY IN ALBERTA

1989 ◽  
Vol 69 (1) ◽  
pp. 1-16 ◽  
Author(s):  
G. M. COEN ◽  
C. Wang
Keyword(s):  
Hydraulic Conductivity ◽  
Measurement Techniques ◽  
Field Measurements ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Soil Morphology ◽  
Soil Series ◽  
Management Procedures ◽  
The Mean

Vertical saturated hydraulic conductivity, as an important soil characteristic, should be part of the information displayed on soil survey maps. As rigorous measurement techniques are relatively slow and cumbersome, a rapid procedure for estimating vertical saturated hydraulic conductivity of soils using soil morphology was tested for Prairie conditions. Morphological estimates of vertical saturated hydraulic conductivity were compared to field measurements using an air entry permeameter for 36 sites representing 25 soil series. Eighty-three percent of the estimated values were within one saturated hydraulic conductivity class of the mean measured value. It was concluded that morphological observations are sufficiently accurate to allow field characterization of pedons. In Alberta, in Chernozemic areas, management procedures do not appear to modify strongly the saturated hydraulic conductivity. This in turn allows useful predictions of saturated hydraulic conductivity to be related to soil series concepts and therefore allows extrapolation to manageable tracts of land using map unit concepts. Key words: Saturated hydraulic conductivity, soil morphology, Alberta, estimating

scholarly journals Sensitivity of hydrodynamic parameters in the simulation of water transfer processes in a permeable pavement

RBRH ◽  
2020 ◽  
Vol 25 ◽  
Author(s):  
Ialy Rayane de Aguiar Costa ◽  
Artur Paiva Coutinho ◽  
Suzana Maria Gico Lima Montenegro ◽  
Ana Emília Carvalho de Gusmão da Cunha Rabelo ◽  
Severino Martins dos Santos Neto ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Hydraulic Conductivity ◽  
Water Transfer ◽  
Saturated Hydraulic Conductivity ◽  
Richards Equation ◽  
Permeable Pavement ◽  
Hydrodynamic Parameters ◽  
Transfer Processes ◽  
Higher Sensitivity ◽  
Daily Time

ABSTRACT The high urbanization process has caused profound changes in the components of the hydrological cycle, causing various problems such as flooding, rainwater degradation, among others. Low Impact Development (LID) techniques have proven to be a viable and effective alternative to stormwater management, reducing runoff, and increasing the infiltration and evapotranspiration capacity of urban areas. The operation prediction of a compensatory technique, such as permeable pavement, depends on the hydrodynamic properties of the permeable pavement layers and the subsoil properties. The numerical solutions based on the solution of Richards’ equation have been the most used to estimate water transfer processes. The objective of this work was to investigate the influence of hydrodynamic parameters on the hydraulic behavior of a permeable pavement installed in Recife-PE. The effect of 5 hydrodynamical parameters was analyzed for a highly heterogeneous permeable pavement. The Hydrus 1-D model was used to simulate water transfer processes on the permeable pavement. Initially, a sensitivity analysis of the mesh refinement degree was performed to simulate the transfer processes in the permeable pavement. The response surface method was applied to the hydrodynamic parameters to perform the sensitivity analysis. The calculations were carried out for hourly and daily time scales. As a result, it was observed that the spatial discretization had no influence on the scenarios of the flow variable. The use of a daily time resolution reduced the influence of events with higher precipitation intensity, underestimating the generation of runoff. The surface runoff showed higher sensitivity to the parameters of the superficial layer, especially to the saturated hydraulic conductivity. The cumulative infiltration and groundwater recharge showed low sensitivity when the hydrodynamic parameters of the retention curve and the saturated hydraulic conductivity varied. The volume of water stored in the profile showed higher sensitivity to the ‘θs’ and ‘n’ parameter of the subbase layer. The use of meteorological input data with different temporal resolutions for the simulation of the water transfer processes in the permeable pavement section demonstrated that the hydrodynamic parameters have a higher influence than the climatic variables in the daily resolution. The use of meteorological data with hourly temporal resolution demonstrated that runoff was hypothetically controlled by meteorological variables. The mesh and parameter sensitivity analysis can influence researches that seek to understand water transfer processes in a structure as a permeable pavement through the Richards’ equation, generating a lower operating cost and speeding up simulations.

A COMPARISON OF THREE FIELD METHODS FOR MEASURING SATURATED HYDRAULIC CONDUCTIVITY

1985 ◽  
Vol 65 (3) ◽  
pp. 563-573 ◽  
Author(s):  
D. M. LEE ◽  
D. E. ELRICK ◽  
W. D. REYNOLDS ◽  
B. E. CLOTHIER
Keyword(s):  
Hydraulic Conductivity ◽  
Frequency Distribution ◽  
Sandy Loam ◽  
Measurement Techniques ◽  
Saturated Hydraulic Conductivity ◽  
Air Entrapment ◽  
Field Methods ◽  
Normal Frequency ◽  
Log Normal ◽  
Guelph Permeameter

The saturated hydraulic conductivity, Ks, was measured on a loamy sand, a fine sandy loam, a silt loam and a clay at four 100-m2-area sites in southern Ontario. Twenty measurements of Ks were obtained by each of three different measurement techniques at each of the four sites. The techniques included: (1) the air-entry permeameter method; (2) the constant head well permeameter method using the Guelph Permeameter; and (3) the falling-head permeameter method applied to small soil cores. The Ks data were found to be better described by the log-normal frequency distribution than by the normal frequency distribution. Statistical comparison of the mean Ks values [Formula: see text] indicated significant differences between some or all of the methods within each site. This site-method interaction was interpreted in terms of the influence of macropores and air entrapment on each of the measurement techniques. The measured Ks values ranged over an order of magnitude on the sand, one to two orders of magnitude on the loams, and three orders of magnitude on the clay. The [Formula: see text] estimates averaged over the three methods were: 3 × 10−5 m∙s−1 for the sand; 2 × 10−6 m∙s−1 for the loams and 1 × 10−7 m∙s−1 for the clay. Although all techniques were able to discriminate between the three soil types, the best choice of method for any particular situation appears dependent on the required type and accuracy of the Ks measurement, soil type, and the various practical constraints on the investigation. Key words: Air-entry permeameter, Guelph Permeameter, falling-head permeameter, spatial variability, macropores, entrapped air

scholarly journals Methods for Measuring the Saturated Hydraulic Conductivity of Tills

1990 ◽  
Vol 21 (2) ◽  
pp. 95-106 ◽  
Author(s):  
Petter D. Jenssen
Keyword(s):  
Hydraulic Conductivity ◽  
Comparative Studies ◽  
Unsaturated Zone ◽  
Representative Sample ◽  
Sample Volume ◽  
Saturated Hydraulic Conductivity ◽  
Saturated Zone ◽  
Traditional Methods ◽  
Dug Wells ◽  
Constant Head

The texture of tills excludes many of the traditional methods for measurement of the saturated hydraulic conductivity. The hydraulic conductivity is scale dependent and for massive relatively homogeneous till a representative sample volume of 104-105 cm3 is suggested. There are no ideal methods for measuring the saturated hydraulic conductivity in till and type of method and equipment should be carefully selected. Studies comparing and evaluating different methods for use in till are few. Comparative studies should be carried out. In the unsaturated zone a variant of the inverse auger hole method using a constant head and a lined pit is recommended. In the saturated zone measurements in dug wells are considered as the most representative method. Correlative methods can only be used for very approximate predictions of the saturated hydraulic conductivity in till.

Prediction of hydraulic conductivity for some Australian soils

Soil Research ◽  
2003 ◽  
Vol 41 (6) ◽  
pp. 1077 ◽  
Author(s):  
Zahra Paydar ◽  
Anthony J. Ringrose-Voase
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Management Practices ◽  
Measurement Techniques ◽  
Effective Porosity ◽  
Saturated Hydraulic Conductivity ◽  
Pedotransfer Functions ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention

Pedotransfer functions and their use in simulation modelling have attracted much attention during recent years. In the absence of measured hydraulic conductivity data, prediction from other soil properties would be most useful. A functional form relating near-saturated hydraulic conductivity to the soil water retention curve based on the Kozeny–Carman equation was investigated on Australian soils. For a dataset comprising a range of soil textures and structural conditions (107 samples with bulk density >1.2 Mg/m3) a power-law relationship between near-saturated hydraulic conductivity, effective porosity, and pore size distribution index was obtained. The function was tested on 2 different datasets for independent evaluation. The results showed poor predictions for most soils in this study. While the reasons for poor predictions might be the difference in the measurement techniques or potentials, it is thought that the proposed function mostly fails predictions on soils with high organic matter and management practices affecting macropores and soil structure (e.g. crust). The proposed function did not show much improvement over the more general form of the Kozeny–Carman equation with empirical coefficients. In the absence of other data, the modified Kozeny–Carman equation (with or without water retention parameters) can be used, with caution, on similar soils and larger scale applications. More data are needed to test the reliabilty of these functions for use in specific locations.

Saturated Hydraulic Conductivity of Clayey Tills and the Role of Fractures

1990 ◽  
Vol 21 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Johnny Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
American Studies ◽  
Field Measurements ◽  
Present Knowledge ◽  
Saturated Hydraulic Conductivity ◽  
Field Observations ◽  
Laboratory Measurements ◽  
Vertical Hydraulic Conductivity ◽  
Data Field

The background for the present knowledge about hydraulic conductivity of clayey till in Denmark is summarized. The data show a difference of 1-2 orders of magnitude in the vertical hydraulic conductivity between values from laboratory measurements and field measurements. This difference is discussed and based on new data, field observations and comparison with North American studies, it is concluded to be primarily due to fractures in the till.

Changes over time in near‐saturated hydraulic conductivity of peat soil following reclamation for agriculture

2019 ◽  
Vol 34 (2) ◽  
pp. 237-243
Author(s):  
Jari Hyväluoma ◽  
Mari Räty ◽  
Janne Kaseva ◽  
Riikka Keskinen
Keyword(s):  
Hydraulic Conductivity ◽  
Peat Soil ◽  
Saturated Hydraulic Conductivity ◽  
Changes Over Time ◽  
Over Time
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