Predicting Water, Gas, and Air Transport Parameters between Soils and across Fields - PhDData

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Predicting Water, Gas, and Air Transport Parameters between Soils and across Fields

The thesis was published by Hansen, Benjamin Isak, in January 2022, Aalborg University.

Abstract:

The purpose of this study was to further enable prediction of water, gas, and air transport parameters between soils and within fields. Using a database of soils across Denmark and newly emerged field data from four Danish cultivated fields, links between saturated hydraulic conductivity (Ks), relative gas diffusivity (DP/Do), air permeability (ka), and more basic and easy-to-measure soil properties were examined. This study presented methods for prediction of Ks between soils with < 20% fines (clay and organic matter) from a ratio of coarse to fine particles and bulk density. Also reported were methods for predicting effective porosity (ϕeff) and DP/Do at -100 cm H2O that were highly accurate between soils with up to 30% fines and predicted well the average behavior in four differently textured fields. Further, links between Ks, fines and ϕeff as well as between ka, fines and ϕeff were presented. Saturated Ks was shown to be strongly linked to ka at soil water matric potentials between -30 cm H2O and -1000 cm H2O, and it was shown that a 1:1 ratio of saturated water permeability (ks) to unsaturated ka occurred between -30 cm H2O and -100 cm H2O in four differently textured fields. Finally, it was shown, through kriged maps, that ka could predict north-south gradients and some field patterns in Ks, thereby setting the stage for development of within-field pedotransfer functions.

The full thesis can be downloaded at :
https://vbn.aau.dk/ws/files/473675435/20173681MTII.pdf


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