Estimation of in situ unsaturated soil hydraulic functions from scaled cumulative drainage data

1994 ◽  
Vol 30 (8) ◽  
pp. 2387-2394 ◽  
Author(s):  
S. O. Eching ◽  
J. W. Hopmans ◽  
W. W. Wallender
Keyword(s):  
Unsaturated Soil ◽  
Soil Hydraulic ◽  
Drainage Data

Unsaturated Soil Hydraulic Properties Identification using Numerical Inversion and In-Situ Experiments from Mnasra Area, Morocco

2019 ◽  
Vol 23 (11) ◽  
pp. 4949-4959
Author(s):  
Hamid Qanza ◽  
Abdellatif Maslouhi ◽  
Said Abboudi ◽  
Hachimi Mustapha ◽  
Abderrahim Hmimou
Keyword(s):  
Unsaturated Soil ◽  
Hydraulic Properties ◽  
Numerical Inversion ◽  
Soil Hydraulic Properties ◽  
In Situ Experiments ◽  
Soil Hydraulic

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.

scholarly journals Use of field and laboratory methods for estimating unsaturated hydraulic properties under different land uses

2015 ◽  
Vol 19 (3) ◽  
pp. 1193-1207 ◽  
Author(s):  
S. Siltecho ◽  
C. Hammecker ◽  
V. Sriboonlue ◽  
C. Clermont-Dauphin ◽  
V. Trelo-ges ◽  
...  
Keyword(s):  
Land Use ◽  
Unsaturated Soil ◽  
Hydraulic Properties ◽  
Rubber Tree ◽  
Measurement Methods ◽  
Soil Parameters ◽  
Forest Site ◽  
Land Uses ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

Abstract. Adequate water management is required to improve the efficiency and sustainability of agricultural systems when water is scarce or over-abundant, especially in the case of land use changes. In order to quantify, to predict and eventually to control water and solute transport into soil, soil hydraulic properties need to be determined precisely. As their determination is often tedious, expensive and time-consuming, many alternative field and laboratory techniques are now available. The aim of this study was to determine unsaturated soil hydraulic properties under different land uses and to compare the results obtained with different measurement methods (Beerkan, disc infiltrometer, evaporation, pedotransfer function). The study has been realized on a tropical sandy soil in a mini-watershed in northeastern Thailand. The experimental plots were positioned in a rubber tree plantation in different positions along a slope, in ruzi grass pasture and in an original forest site. Non-parametric statistics demonstrated that van Genuchten unsaturated soil parameters (Ks, α and n) were significantly different according to the measurement methods employed, whereas the land use was not a significant discriminating factor when all methods were considered together. However, within each method, parameters n and α were statistically different according to the sites. These parameters were used with Hydrus1D for a 1-year simulation and computed pressure head did not show noticeable differences for the various sets of parameters, highlighting the fact that for modeling, any of these measurement methods could be employed. The choice of the measurement method would therefore be motivated by the simplicity, robustness and its low cost.

scholarly journals Joint Distributions of the Unsaturated Soil Hydraulic Parameters and their Effect on Other Variates

2004 ◽  
Vol 3 (4) ◽  
pp. 1492-1492 ◽  
Author(s):  
G. H. de Rooij ◽  
R. T. A. Kasteel ◽  
A. Papritz ◽  
H. Fluhler
Keyword(s):  
Unsaturated Soil ◽  
Hydraulic Parameters ◽  
Joint Distributions ◽  
Soil Hydraulic Parameters ◽  
Soil Hydraulic
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