The indirect estimation of saturated hydraulic conductivity of soils, using measurements of gas permeability. I. Laboratory testing with dry granular soils

Soil Research ◽  
2006 ◽  
Vol 44 (7) ◽  
pp. 719 ◽  
Author(s):  
Tony Wells ◽  
Stephen Fityus ◽  
David W. Smith ◽  
Hlwan Moe
Keyword(s):  
Hydraulic Conductivity ◽  
Gas Flow ◽  
Gas Permeability ◽  
Cylindrical Tube ◽  
Saturated Hydraulic Conductivity ◽  
Granular Soils ◽  
Soil Hydraulic Conductivity ◽  
Wide Range ◽  
Soil Hydraulic

A comprehensive knowledge of soil hydraulic conductivity is essential when modelling the distribution of soil moisture within soil profiles and across catchments. The high spatial variability of soil hydraulic conductivity, however, necessitates the taking of many in situ measurements, which are costly, time-consuming, and labour-intensive. This paper presents an improved method for indirectly determining the saturated hydraulic conductivity of granular materials via an in situ gas flow technique. The apparatus employed consists of a cylindrical tube which is embedded in the soil to a prescribed depth. Nitrogen at a range of pressures was supplied to the tube and allowed to escape by permeating through the soil. A 3-dimensional, axisymmetric, steady-state, finite element flow model was then used to determine the value of the soil intrinsic gas permeability which produces the best fit to the pressure–air flow data. Saturated hydraulic conductivities estimated from the application of the gas flow technique to 5 granular soils covering a wide range of permeabilities were in close agreement with values determined using a conventional permeameter. The results of this preliminary study demonstrate the potential of this approach to the indirect determination of saturated hydraulic conductivity based on measurement of gas flow rates in granular and structured soils.

Application of In-situ Lysimetric Studies for Determining Soil Hydraulic Conductivity

2009 ◽  
Vol 27 (5) ◽  
pp. 595-606 ◽  
Author(s):  
B. Hanumantha Rao ◽  
V. Sridhar ◽  
R. R. Rakesh ◽  
D. N. Singh ◽  
P. K. Narayan ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic

scholarly journals River Buffer Effectiveness in Controlling Surface Runoff Based on Saturated Soil Hydraulic Conductivity

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2383
Author(s):  
Hatma Suryatmojo ◽  
Ken’ichirou Kosugi
Keyword(s):  
Hydraulic Conductivity ◽  
Surface Runoff ◽  
Hydraulic Properties ◽  
Canopy Cover ◽  
Selective Logging ◽  
Saturated Hydraulic Conductivity ◽  
Soil Hydraulic Properties ◽  
Near Surface ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic

In tropical Indonesia, rainforests are managed by an intensive forest management system (IFMS). The IFMS has promoted selective logging for timber harvesting and intensive line planting to enrich the standing stock. The implementation of the IFMS has reduced the forest canopy cover, disturbed the surface soil, changed the soil hydraulic properties, and increased direct runoff and soil erosion. Investigation of the IFMS impact on soil hydraulic properties and the generation of surface runoff using a saturated hydraulic conductivity model is needed. Soil hydraulic properties were investigated on 11 plots, including one virgin forest plot and 10 plots at different operational periods of the IFMS. A two-dimensional saturated soil water flow simulation was applied to generate surface runoff from different periods of the IFMS. The main parameters of canopy cover, net rainfall, and saturated hydraulic conductivity were used in the simulations. A simulation scenario of a surface runoff hydrograph in different forest operations was used to analyze the river buffer effectiveness. The results showed that fundamental IFMS activities associated with mechanized selective logging and intensive line planting have reduced the soil hydraulic conductivity within the near-surface profile. The recovery time for near-surface Ks on non-skidder tracks was between 10 and 15 years, whereas on the skidder tracks it was more than 20 years. Forest disturbances have altered the typical surface hydrological pathways, thereby creating the conditions for more surface runoff on disturbed surfaces than on undisturbed surfaces. Maintaining the buffer area is an effective means to reduce the peak discharge and surface runoff in the stream channel.

scholarly journals Instrumentation for Measurement of Laboratory and In-Situ Soil Hydraulic Conductivity Properties

10.5772/19866 ◽  
2011 ◽  
Author(s):  
Jose Antonio Gutierrez Gnecchi ◽  
Alberto Gomez-Tagle ◽  
Philippe Lobit ◽  
Adriana Tellez ◽  
Arturo Mendez ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic

Improvement on the Method of Measuring Soil Saturated Hydraulic Conductivity by Using Permeating Bucket

2012 ◽  
Vol 518-523 ◽  
pp. 4735-4739
Author(s):  
Feng Tai Guo ◽  
Sha Wu ◽  
Dong Juan Cheng ◽  
Ya Min Liu
Keyword(s):  
Hydraulic Conductivity ◽  
Layer Thickness ◽  
Water Layer ◽  
Saturated Hydraulic Conductivity ◽  
Saturated Soil ◽  
Water Volume ◽  
Soil Hydraulic Conductivity ◽  
Water Head ◽  
Soil Hydraulic

The method of measuring saturated soil hydraulic conductivity by using permeating bucket is easy and simple and the instrument is cheap. The water volume must be measuring for many times, meanwhile the water must be added on the top of permeating bucket to sustain the water layer thickness. Based on the principles of supplying water in the fixed water head by Marriott bottle, the method mentioned above is improved, which can reduce the experiment work and improve the experiment accuracy.

Simplified estimation of unsaturated soil hydraulic conductivity using bulk electrical conductivity and particle size distribution

Soil Research ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
Mohammad Reza Neyshabouri ◽  
Mehdi Rahmati ◽  
Claude Doussan ◽  
Boshra Behroozinezhad
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Hydraulic Conductivity ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Unsaturated Soil ◽  
Soil Core ◽  
Soil Hydraulic Conductivity ◽  
Core Samples ◽  
Soil Hydraulic

Unsaturated soil hydraulic conductivity K is a fundamental transfer property of soil but its measurement is costly, difficult, and time-consuming due to its large variations with water content (θ) or matric potential (h). Recently, C. Doussan and S. Ruy proposed a method/model using measurements of the electrical conductivity of soil core samples to predict K(h). This method requires the measurement or the setting of a range of matric potentials h in the core samples—a possible lengthy process requiring specialised devices. To avoid h estimation, we propose to simplify that method by introducing the particle-size distribution (PSD) of the soil as a proxy for soil pore diameters and matric potentials, with the Arya and Paris (AP) model. Tests of this simplified model (SM) with laboratory data on a broad range of soils and using the AP model with available, previously defined parameters showed that the accuracy was lower for the SM than for the original model (DR) in predicting K (RMSE of logK = 1.10 for SM v. 0.30 for DR; K in m s–1). However, accuracy was increased for SM when considering coarse- and medium-textured soils only (RMSE of logK = 0.61 for SM v. 0.26 for DR). Further tests with 51 soils from the UNSODA database and our own measurements, with estimated electrical properties, confirmed good agreement of the SM for coarse–medium-textured soils (<35–40% clay). For these textures, the SM also performed well compared with the van Genuchten–Mualem model. Error analysis of SM results and fitting of the AP parameter showed that most of the error for fine-textured soils came from poorer adequacy of the AP model’s previously defined parameters for defining the water retention curve, whereas this was much less so for coarse-textured soils. The SM, using readily accessible soil data, could be a relatively straightforward way to estimate, in situ or in the laboratory, K(h) for coarse–medium-textured soils. This requires, however, a prior check of the predictive efficacy of the AP model for the specific soil investigated, in particular for fine-textured/structured soils and when using previously defined AP parameters.

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