scholarly journals Free-form estimation of the unsaturated soil hydraulic properties by inverse modeling using global optimization

2007 ◽  
Vol 43 (7) ◽  
Author(s):  
S. C. Iden ◽  
W. Durner
Keyword(s):  
Global Optimization ◽  
Unsaturated Soil ◽  
Inverse Modeling ◽  
Hydraulic Properties ◽  
Free Form ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

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 Inverse estimation of soil hydraulic properties and water repellency following artificially induced drought stress

2018 ◽  
Vol 66 (2) ◽  
pp. 170-180 ◽  
Author(s):  
Vilim Filipović ◽  
Thomas Weninger ◽  
Lana Filipović ◽  
Andreas Schwen ◽  
Keith L. Bristow ◽  
...  
Keyword(s):  
Soil Water ◽  
Inverse Modeling ◽  
Hydraulic Properties ◽  
Global Climate ◽  
Water Repellency ◽  
Irrigation Event ◽  
Water Infiltration ◽  
Soil Hydraulic Properties ◽  
Soil Water Repellency ◽  
Soil Hydraulic

AbstractGlobal climate change is projected to continue and result in prolonged and more intense droughts, which can increase soil water repellency (SWR). To be able to estimate the consequences of SWR on vadose zone hydrology, it is important to determine soil hydraulic properties (SHP). Sequential modeling using HYDRUS (2D/3D) was performed on an experimental field site with artificially imposed drought scenarios (moderately M and severely S stressed) and a control plot. First, inverse modeling was performed for SHP estimation based on water and ethanol infiltration experimental data, followed by model validation on one selected irrigation event. Finally, hillslope modeling was performed to assess water balance for 2014. Results suggest that prolonged dry periods can increase soil water repellency. Inverse modeling was successfully performed for infiltrating liquids, water and ethanol, withR2and model efficiency (E) values both > 0.9. SHP derived from the ethanol measurements showed large differences in van Genuchten-Mualem (VGM) parameters for the M and S plots compared to water infiltration experiments. SWR resulted in large saturated hydraulic conductivity (Ks) decrease on the M and S scenarios. After validation of SHP on water content measurements during a selected irrigation event, one year simulations (2014) showed that water repellency increases surface runoff in non-structured soils at hillslopes.

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
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